Attorney Docket No.38215.0006P1 A METHOD OF MINIMIZING OR ELIMINATING NEPHROTOXICITY IN PATIENTS UNDERGOING TREATMENT WITH ANTIMICROBIAL OR ANTICANCER DRUGS CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This Application claims the benefit of U.S. Application No.63/595,641, filed on November 02, 2023, the contents of which are incorporated herein by reference in their entirety. BACKGROUND [0002] Drug-induced nephrotoxicity is a significant health problem for which there is presently no satisfactory solution. Nephrotoxicity typically manifests itself as a loss in glomerular filtration rate (GFR). In some cases, the patient may experience transient acute kidney injury (AKI). However, in other cases, drug induced nephrotoxicity can lead to chronic kidney disease (CKD) and reduced long-term quality of life. This off-target nephrotoxicity frequently limits a drug’s use and thus its effectiveness (Pabla et al.2008). Accordingly, special attention must be paid to patients receiving nephrotoxic drugs to the possibility of kidney injury. [0003] One category of drugs that is particularly well known to cause impaired kidney function is chemotherapeutic agents, in particular, platinum-based chemotherapeutic agents such as cisplatin. Cisplatin-associated nephrotoxicity is usually progressive, dose-dependent, and frequently irreversible. Reduction of the dose or the duration of cisplatin treatment, or switching to a less efficacious alternative to minimize toxic side effects, often results in a choice between potential cancer recurrence and kidney damage. Another category of drugs that is known to cause impaired kidney function is antimicrobial drugs, such as aminoglycosides (e.g., gentamicin and colistin), and vancomycin. Thus, there is a significant medical need for nephroprotective strategies that do not diminish the anticancer efficacy of cisplatin. [0004] Cisplatin induced nephrotoxicity is thought to be produced by several distinct mechanisms. Cisplatin achieves its chemotherapeutic effect by crosslinking DNA and inducing the DNA damage response, apoptosis, and cell death. Cisplatin is excreted in urine, and accumulation of cisplatin and its toxic metabolites in PTECs induces various intracellular stresses, including DNA damage, mitochondrial pathology, oxidative stress, and endoplasmic reticulum stress (Tang et al.2022). Cisplatin enters PTECs from circulation via the organic
Attorney Docket No.38215.0006P1 cation transporter 2 (OCT2) and human copper transport protein 1 (Ctr1) (Manohar et al.2018). Cisplatin is transformed to a nephrotoxin by a series of enzymes as part of the xenobiotic biotransformation pathway in the proximal tubule cells (Townsend et al.2003). Activation begins with the formation of a glutathione-conjugate that is metabolized to a cysteinyl-glycine- conjugate in the tubule lumen to a cysteine conjugate. This cysteine conjugate is then re absorbed by the proximal tubule cell, and finally transformed to a reactive thiol, that can bind proteins and contribute to toxicity (Townsend 2003, Mazari 2023). [0005] One strategy for minimizing the nephrotoxic effects is to block entry of cisplatin into the PTECs by, for example, administration of an OCT inhibitor. However, such strategies have only produced partial protection against nephrotoxicity. Further, OTC inhibitors can compromise cisplatin uptake by cancer cells and, therefore, can reduce its therapeutic effect (Pabla et al. 2008). It was also noted that the majority of cisplatin administered is recovered from lysosomes on the apical side of PTECs, indicating a major role of vesicle cycling in accumulation and nephrotoxicity (Camano 2010). [0006] In view of these observations, it has been theorized that accumulation of platinum agents in the kidney may be mediated by megalin, a large (approximately 600 kD) glycoprotein member of the low-density lipoprotein (LDL) receptor family and a major endocytic receptor in PTEC (Saito et al.2010). Megalin (also known as low-density lipoprotein receptor–related protein 2 [LRP2]) is strongly expressed at the of brush border membrane (BBM) of proximal tubules and plays a role in regulating the BBM. Megalin mediates intracellular signal transduction and plays a pivotal role in the reabsorption of glomerular-filtered substances (Saito et al.2010). [0007] Cilastatin is a megalin antagonist (Humanes 2012; Hori 2017). Currently, cilastatin is approved in the United States as part of the fixed dose combination products PRIMAXIN
® (imipenem and cilastatin sodium) and RECARBRIO
® (imipenem/cilastatin/relebactam) by virtue of its ability to inhibit the human enzyme dehydropeptidase-I (DHP-I). In this way, cilastatin can extend the half-life of imipenem, which is degraded by DHP-1 (Keynan 1995). Cilastatin antagonism of megalin, however, occurs by a separate mechanism, independent of DHP-I metabolism. [0008] The ability of cilastatin to bind to megalin and to attenuate cisplatin nephrotoxicity has been demonstrated both in vitro (see, e.g., Camano et al.2010; Becerir, et al.2021; and Hori et
Attorney Docket No.38215.0006P1 al.2017) and in vivo animal studies (see, e.g., Humanes et al.2012; Hori et al.2017; Humanes et al.2017; Moreno-Gordaliza et al.2018; Moreno-Gordaliza et al.2021a; Moreno-Gordaliza, et al. 2021b; Arita et al.2021; and Gonzalez-Fernandez, et al.2022). Further, a clinical study demonstrating proof of concept of imipenem/cilastatin (I/C) prophylaxis for cisplatin-induced nephrotoxicity was conducted in patients with peritoneal carcinomatosis undergoing cytoreductive surgery (CRS) and hyperthermic IP intraoperative chemotherapy (HIPEC- cisplatin) (Zaballos, et al.2021). [0009] Although much work has been done to elucidate the molecular pathway by which a toxic agent gains entry into an organ, such as the kidney, the appropriate posology in which the protective agent, a megalin antagonist is administered has yet to be determined. Neither has the appropriate start time of administration or the dose or duration of administration been elucidated. As such, methods of using cilastatin to treat drug-induced nephrotoxicity in human patients remain limited. Thus, there is a need for nephroprotective compositions and methods to prevent or mitigate nephrotoxicity associated with chemotherapeutic regimens including platinum-based chemotherapeutic agents in human patients. The present invention describes and solves the significant challenges to developing a treatment for drug-induced nephrotoxicity including, but not limited to, identifying the optimum route of administration, the correct dosing regimen, and the correct dose. SUMMARY [00010] In accordance with the purpose(s) of the invention, as embodied and broadly described herein, the invention, in one aspect, relates to methods for treating, preventing, reducing, or otherwise mitigating nephrotoxicity comprising the administration of a megalin antagonist such as, for example, cilastatin, or a pharmaceutically acceptable salt thereof. As further detailed herein, megalin can bind platinum-based chemotherapeutic agents, such as cisplatin, as well as antimicrobial drugs, such as aminoglycosides (e.g., gentamicin and colistin), and vancomycin. Cilastatin competes for megalin binding. It is, therefore, theorized that administration of cilastatin will inhibit drug-induced nephrotoxicity mediated via megalin, thereby avoiding the need to lower the dose of drug. Thus, a more effective treatment is described. [00011] Thus, disclosed are methods of treating or preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically
Attorney Docket No.38215.0006P1 acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. In some aspects, a nephroprotective agent, such as a megalin antagonist like cilastatin, is administered at a time prior to or coincident with the administration of the platinum-based chemotherapy agent so as to ensure that the peak cilastatin blood concentration is sufficient to provide optimum megalin blockade prior to or coincident with the peak blood concentration of the platinum-based chemotherapy agent. In some aspects, administration of the megalin antagonist is continued for a period of time to provide effective blockade while the plasma concentration of the nephrotoxic agent is in circulation. [00012] Disclosed are methods of reducing/mitigating or preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. [00013] Also disclosed are methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. In some aspects, a nephroprotective agent, such as a megalin antagonist like cilastatin, is administered at a time prior to or coincident with the administration of the antimicrobial therapy agent so as to ensure that the peak cilastatin blood concentration is prior to or coincident with the peak blood concentration of the antimicrobial therapy agent. In some aspects, administration of the megalin antagonist is continued for a period of time to provide effective blockade while the plasma concentration of the nephrotoxic agent is in circulation. [00014] Disclosed are methods of reducing/mitigating or preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. [00015] [00016] Additional advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or can be learned by practice of the
Attorney Docket No.38215.0006P1 invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS [00017] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects and together with the description serve to explain the principles of the invention. [00018] FIG.1A and FIG.1B show representative Cryo-EM structures of megalin. [00019] FIG.2 shows a representative schematic illustrating the hypothesized metabolic pathways of cisplatin in the kidneys. M1-M4 = cisplatin metabolites; OCT= organic cation transporter; OCT2, organic cation; transporter 2; GSTP1=glutathione S transferase pi 1; GGT1=γ glutamyltransferase 1; MATE1 = multidrug and toxin extrusion protein 1. MRP2= multidrug resistance associated protein 2; CTR1= copper transporter 1; AP = aminodipeptidase. [00020] FIG.3 shows a representative schematic illustrating the hypothesized effect of administering cilastatin along with cisplatin. M1-M4 = cisplatin metabolites; OCT= organic cation transporter; OCT2, organic cation; transporter 2; GSTP1=glutathione S transferase pi 1; GGT1=γ glutamyltransferase 1; MATE1 = multidrug and toxin extrusion protein 1. MRP2= multidrug resistance associated protein 2; CTR1= copper transporter 1; AP = aminodipeptidase. [00021] FIG.4 shows a representative schematic illustrating that megalin blockade with cilastatin suppresses other acute kidney injury (ACI). [00022] FIG.5 shows a representative diagram illustrating the open-label pharmacokinetic and safety study design. [00023] FIG.6A-D show representative diagrams summarizing the results of the open-label pharmacokinetic and safety study of cilastatin in patients receiving cisplatin chemotherapy. [00024] FIG.7 shows representative serum platinum concentrations over time from patients given imipenem/cilastatin (I/C) prior to cisplatin. [00025] FIG.8 shows representative data illustrating serum creatinine levels after cisplatin and I/C administration.
Attorney Docket No.38215.0006P1 [00026] FIG.9 shows representative data illustrating split glomerular filtration rate (sGFR) after cisplatin and I/C administration. [00027] FIG.10 shows representative data illustrating the urinary N-acetyl-β-D- glucosaminidase/creatinine ratio after cisplatin and I/C administration. [00028] FIG.11A and FIG.11B show representative data illustrating a SAAM II computer program fit to data generated by Norrby et al. (1984), which was obtained after IV administration of 250 mg cilastatin. [00029] FIG.12 shows representative data illustrating a pharmacokinetic model as diagrammed by the SAAM program. [00030] FIG.13 shows representative data illustrating the predicted concentrations over time of cilastatin loading dose and continuous infusion in subjects with mild renal impairment. [00031] FIG.14 shows representative data illustrating the predicted concentrations over time of cilastatin intermittent infusion in subjects with mild renal impairment. [00032] FIG.15A and FIG.15B show a representative schedule of events for the randomized, placebo-controlled clinical study to evaluate the safety, efficacy, and pharmacokinetics of cilastatin compared to placebo in patients receiving cisplatin. Abbreviations: eCrCL, estimated creatinine clearance; ECOG, Eastern Cooperative Oncology Group; ET, early termination; hCG, human chorionic gonadotropin; AE, adverse event; min=minutes.
a Subjects who withdraw from the study early will be asked to complete ET procedures.
b Subject of childbearing potential only.
c Perform urine pregnancy test and confirm negative prior to administering study drug at Day 1 of each cycle.
d Cycle 1 only for assessments other than pregnancy test. Perform assessments prior to administering study drug.
e It is recommended that the ECOG assessment be completed prior to study drug administration.
f It is recommended that vital signs should be collected prior to, or at least 10 minutes after, clinical laboratory tests.
g The results from predose labs to calculate eCrCl and any dose adjustments must be available before study drug administration. Laboratory results collected within the 72 hours prior to dose administration may be used to calculate eCrCl and dose.
h The start of study drug administration will be considered Time 0 for all safety and PK assessments.
I Study drug is intended to begin administration immediately prior to cisplatin. The start of study drug administration will be considered as Time 0. The time window is +5 minutes for the administration of cisplatin relative to the start of study drug.
j Assessments for AEs will be collected from signing of the informed consent form (ICF)
Attorney Docket No.38215.0006P1 through EOS.
k Record all concomitant medications taken from the time the subject signs the ICF through the EOS.
l If any biopsy or surgical resection is performed as part of standard of care, samples will be obtained, if possible, for evaluation of megalin expression. [0001] While aspects of the present invention can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of skill in the art will understand that each aspect of the present invention can be described and claimed in any statutory class. Unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification. DESCRIPTION [00033] The disclosed method and compositions may be understood more readily by reference to the following detailed description of particular embodiments and the Examples included therein. [00034] It is to be understood that the disclosed method and compositions are not limited to specific synthetic compositions, specific methods, specific analytical techniques, or to particular reagents unless otherwise specified, and, as such, may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. [00035] Disclosed are materials, compositions, and components that can be used for, can be used in conjunction with, can be used in preparation for, or are products of the disclosed method and compositions. These and other materials are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these materials are disclosed that while specific reference of each various individual and collective combinations and permutations of these compounds may not be explicitly disclosed, each is specifically contemplated and described herein. Thus, if a class of molecules A, B, and C are disclosed as well as a class of
Attorney Docket No.38215.0006P1 molecules D, E, and F and an example of a combination molecule, A-D is disclosed, then even if each is not individually recited, each is individually and collectively contemplated. Thus, is this example, each of the combinations A-E, A-F, B-D, B-E, B-F, C-D, C-E, and C-F are specifically contemplated and should be considered disclosed from disclosure of A, B, and C; D, E, and F; and the example combination A-D. Likewise, any subset or combination of these is also specifically contemplated and disclosed. Thus, for example, the sub-group of A-E, B-F, and C-E are specifically contemplated and should be considered disclosed from disclosure of A, B, and C; D, E, and F; and the example combination A-D. This concept applies to all aspects of this application including, but not limited to, steps in methods of making and using the disclosed compositions. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific embodiment or combination of embodiments of the disclosed methods, and that each such combination is specifically contemplated and should be considered disclosed. A. DEFINITIONS [00036] It is understood that the disclosed method and compositions are not limited to the particular methodology, protocols, and reagents described as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention which will be limited only by the appended claims. [00037] It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to “a platinum-based therapy agent” includes a plurality of such platinum- based therapy agents, reference to “the platinum-based therapy agent” is a reference to one or more platinum-based therapy agents and equivalents thereof known to those skilled in the art, and so forth. [00038] As used in the specification and in the claims, the term “comprising” can include the aspects “consisting of” and “consisting essentially of.” [00039] Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, also specifically contemplated and considered disclosed is the range from the one particular value and/or to the other particular
Attorney Docket No.38215.0006P1 value unless the context specifically indicates otherwise. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another, specifically contemplated embodiment that should be considered disclosed unless the context specifically indicates otherwise. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint unless the context specifically indicates otherwise. Finally, it should be understood that all of the individual values and sub-ranges of values contained within an explicitly disclosed range are also specifically contemplated and should be considered disclosed unless the context specifically indicates otherwise. The foregoing applies regardless of whether in particular cases some or all of these embodiments are explicitly disclosed. [00040] As used herein, the terms “about” and “at or about” mean that the amount or value in question can be the value designated some other value approximately or about the same. It is generally understood, as used herein, that it is the nominal value indicated ±10% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such. It is understood that where “about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise. [00041] References in the specification and concluding claims to parts by weight of a particular element or component in a composition denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a compound containing 2 parts by weight of component X and 5 parts by weight component Y, X and Y are present at a weight ratio of 2:5, and are present in such ratio regardless of whether additional components are contained in the compound. [00042] A weight percent (wt. %) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included.
Attorney Docket No.38215.0006P1 [00043] “Optional” or “optionally” means that the subsequently described event, circumstance, or material may or may not occur or be present, and that the description includes instances where the event, circumstance, or material occurs or is present and instances where it does not occur or is not present. [00044] As used herein, the term “subject” or “patient” refers to any organism to which a composition of this invention may be administered, e.g., for experimental, diagnostic, and/or therapeutic purposes. Typical subjects include animals (e.g., mammals such as non-human primates, and humans; avians; domestic household or farm animals such as cats, dogs, sheep, goats, cattle, horses and pigs; laboratory animals such as mice, rats and guinea pigs; rabbits; fish; reptiles; zoo and wild animals). Typically, “subjects” are animals, including mammals such as humans and primates; and the like. [00045] As used herein, the term “treatment” or “treating” refers to partially or completely alleviating, ameliorating, relieving, preventing, delaying onset of, inhibiting or slowing progression of, reducing severity of, and/or reducing incidence of nephrotoxicity caused by antimicrobial therapy and/or platinum-based therapy agents (e.g., platinum-based chemotherapy agent). Treatment can be administered to a subject who does not exhibit signs of nephrotoxicity and/or to a subject who exhibits only early signs of nephrotoxicity. This term includes active treatment, that is, treatment directed specifically toward the improvement of nephrotoxicity caused by platinum-based therapy and/or antimicrobial therapy agents, and also includes causal treatment, that is, treatment directed toward removal of the cause of the nephrotoxicity. In addition, this term includes palliative treatment, that is, treatment designed for the relief of symptoms rather than the curing of the nephrotoxicity; preventative treatment, that is, treatment directed to minimizing or partially or completely inhibiting the development of the nephrotoxicity; and supportive treatment, that is, treatment employed to supplement another specific therapy directed toward the improvement of the nephrotoxicity. In various aspects, the term covers any treatment of a subject, including a mammal (e.g., a human), and includes: (i) preventing nephrotoxicity from occurring in a subject that can be predisposed to nephrotoxicity but has not yet been diagnosed as having it; (ii) inhibiting nephrotoxicity, i.e., arresting its development; or (iii) relieving nephrotoxicity, i.e., causing regression of nephrotoxicity. In one aspect, the subject is a mammal such as a primate, and, in a further aspect, the subject is a human. The term “subject” also includes domesticated animals (e.g., cats, dogs, etc.), livestock
Attorney Docket No.38215.0006P1 (e.g., cattle, horses, pigs, sheep, goats, etc.), and laboratory animals (e.g., mouse, rabbit, rat, guinea pig, fruit fly, etc.). [00046] As used herein, the term “prevent” or “preventing” is meant to mean minimize the chance that a subject who has an increased susceptibility for developing a disease, disorder or condition will develop the disease, disorder or condition (e.g., nephrotoxicity). For example, prevent as used herein can mean minimize the chance that a subject who has an increased susceptibility for developing hearing impairment will develop it. [00047] As used herein, the term “diagnosed” means having been subjected to a physical examination by a person of skill, for example, a physician, and found to have a condition that can be diagnosed or treated by the compounds, compositions, or methods disclosed herein. [00048] As used herein, the terms “administering” and “administration” refer to any method of providing a disclosed composition (e.g., platinum-based chemotherapy) to a subject. Such methods are well known to those skilled in the art and include, but are not limited to: oral administration, transdermal administration, administration by inhalation, nasal administration, topical administration, intravaginal administration, ophthalmic administration, auricular administration, intracerebral administration, rectal administration, sublingual administration, buccal administration, and parenteral administration, including injectable such as intravenous administration, intra-arterial administration, intramuscular administration, intraperitoneal, and subcutaneous administration. Administration can be continuous or intermittent. In various aspects, a preparation can be administered therapeutically; that is, administered to treat an existing disease or condition. In further various aspects, a preparation can be administered prophylactically; that is, administered for prevention of a disease or condition. [00049] An “effective amount” of a composition is that amount of composition which is sufficient to provide a beneficial effect to the subject to which the composition is administered. The phrase “therapeutically effective amount,” as used herein, refers to an amount that is sufficient or effective to prevent or treat (delay or prevent the onset of, prevent the progression of, inhibit, decrease or reverse) a disease or condition, including alleviating symptoms of such diseases. For example, a therapeutically effective amount of cilastatin, or a pharmaceutically acceptable salt thereof, is an amount that is sufficient to reduce or prevent nephrotoxicity. [00050] As used herein, “dosage form” means a pharmacologically active material in a medium, carrier, vehicle, or device suitable for administration to a subject. A dosage form can comprise a
Attorney Docket No.38215.0006P1 disclosed compound, a product of a disclosed method of making, or a salt, solvate, or polymorph thereof, in combination with a pharmaceutically acceptable excipient, such as a preservative, buffer, saline, or phosphate buffered saline. Dosage forms can be made using conventional pharmaceutical manufacturing and compounding techniques. Dosage forms can comprise inorganic or organic buffers (e.g., sodium or potassium salts of phosphate, carbonate, acetate, or citrate) and pH adjustment agents (e.g., hydrochloric acid, sodium or potassium hydroxide, salts of citrate or acetate, amino acids and their salts) antioxidants (e.g., ascorbic acid, alpha- tocopherol), surfactants (e.g., polysorbate 20, polysorbate 80, polyoxyethylene9-10 nonyl phenol, sodium desoxycholate), solution and/or cryo/lyo stabilizers (e.g., sucrose, lactose, mannitol, trehalose), osmotic adjustment agents (e.g., salts or sugars), antibacterial agents (e.g., benzoic acid, phenol, gentamicin), antifoaming agents (e.g., polydimethylsilozone), preservatives (e.g., thimerosal, 2-phenoxyethanol, EDTA), polymeric stabilizers and viscosity-adjustment agents (e.g., polyvinylpyrrolidone, poloxamer 488, carboxymethylcellulose) and co-solvents (e.g., glycerol, polyethylene glycol, ethanol). A dosage form formulated for injectable use can have a disclosed compound, a product of a disclosed method of making, or a salt, solvate, or polymorph thereof, suspended in sterile saline solution for injection together with a preservative. [00051] As used herein, the terms “therapeutic agent” include any synthetic or naturally occurring biologically active compound or composition of matter which, when administered to an organism (human or nonhuman animal), induces a desired pharmacologic, immunogenic, and/or physiologic effect by local and/or systemic action. The term therefore encompasses those compounds or chemicals traditionally regarded as drugs, vaccines, and biopharmaceuticals including molecules such as proteins, peptides, hormones, nucleic acids, gene constructs and the like. Examples of therapeutic agents are described in well-known literature references such as the Merck Index (14
th edition), the Physicians' Desk Reference (64
th edition), and The Pharmacological Basis of Therapeutics (12
th edition) , and they include, without limitation, medicaments; vitamins; mineral supplements; substances used for the treatment, prevention, diagnosis, cure or mitigation of a disease or illness; substances that affect the structure or function of the body, or pro-drugs, which become biologically active or more active after they have been placed in a physiological environment. For example, the term “therapeutic agent” includes compounds or compositions for use in all of the major therapeutic areas including, but not limited to, adjuvants; anti-infectives such as antibiotics and antiviral agents; analgesics and
Attorney Docket No.38215.0006P1 analgesic combinations, anorexics, anti-inflammatory agents, anti-epileptics, local and general anesthetics, hypnotics, sedatives, antipsychotic agents, neuroleptic agents, antidepressants, anxiolytics, antagonists, neuron blocking agents, anticholinergic and cholinomimetic agents, antimuscarinic and muscarinic agents, antiadrenergics, antiarrhythmics, antihypertensive agents, hormones, and nutrients, antiarthritics, antiasthmatic agents, anticonvulsants, antihistamines, antinauseants, antineoplastics, antipruritics, antipyretics; antispasmodics, cardiovascular preparations (including calcium channel blockers, beta-blockers, beta-agonists and antiarrythmics), antihypertensives, diuretics, vasodilators; central nervous system stimulants; cough and cold preparations; decongestants; diagnostics; hormones; bone growth stimulants and bone resorption inhibitors; immunosuppressives; muscle relaxants; psychostimulants; sedatives; tranquilizers; proteins, peptides, and fragments thereof (whether naturally occurring, chemically synthesized or recombinantly produced); and nucleic acid molecules (polymeric forms of two or more nucleotides, either ribonucleotides (RNA) or deoxyribonucleotides (DNA) including both double- and single-stranded molecules, gene constructs, expression vectors, antisense molecules and the like), small molecules (e.g., doxorubicin) and other biologically active macromolecules such as, for example, proteins and enzymes. The agent may be a biologically active agent used in medical, including veterinary, applications and in agriculture, such as with plants, as well as other areas. The term "therapeutic agent" also includes without limitation, medicaments; vitamins; mineral supplements; substances used for the treatment, prevention, diagnosis, cure or mitigation of disease or illness; or substances which affect the structure or function of the body; or pro- drugs, which become biologically active or more active after they have been placed in a predetermined physiological environment. [00052] The phrase “loading dose” means an initial dose given prior to a maintenance dose. [00053] The phrase “maintenance dose” means a dose given on a continuous or frequent basis to provide continued exposure to a drug. [00054] The phrase “platinum-based chemotherapy” means treatment using a platinum-based antineoplastic or chemotherapeutic agent (e.g., cisplatin, carboplatin, oxaliplatin, nedaplatin, triplatin tetranitrate, phenanthriplatin, picoplatin, or satraplatin). [00055] The phrase “antimicrobial therapy” means treatment using a drug having antimicrobial effects (e.g., aminoglycosides such as gentamicin, kanamycin, mycifradin, neomycin,
Attorney Docket No.38215.0006P1 tobramycin, streptomycin, plazomycin, and amikacin, polymyxin antibiotics such as colistin and glycopeptide antibiotics such as vancomycin). [00056] The term “cilastatin” throughout can also include a pharmaceutically acceptable salt thereof. [00057] The term “pharmaceutically acceptable” describes a material that is not biologically or otherwise undesirable, i.e., without causing an unacceptable level of undesirable biological effects or interacting in a deleterious manner. [00058] The term “pharmaceutically acceptable salt,” as used herein, represents those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and animals without undue toxicity, irritation, allergic response and the like and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, pharmaceutically acceptable salts are described in: Berge et al., J. Pharmaceutical Sciences 66: 1-19, 1977 and in Pharmaceutical Salts: Properties, Selection, and Use, (Eds. P. H. Stahl and C. G. Wermuth), Wiley-VCR, 2008. The salts can be prepared in situ during the final isolation and purification of the compounds described herein or separately by reacting the free base group with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2- naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to anmonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. Typical pharmaceutically acceptable salts of cilastatin are sodium salts and ammonium salts. [00059] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed method and
Attorney Docket No.38215.0006P1 compositions belong. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present method and compositions, the particularly useful methods, devices, and materials are as described. Publications cited herein and the material for which they are cited are hereby specifically incorporated by reference. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such disclosure by virtue of prior invention. No admission is made that any reference constitutes prior art. The discussion of references states what their authors assert, and applicants reserve the right to challenge the accuracy and pertinence of the cited documents. It will be clearly understood that, although a number of publications are referred to herein, such reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art. [00060] Throughout the description and claims of this specification, the word “comprise” and variations of the word, such as “comprising” and “comprises,” means “including but not limited to,” and is not intended to exclude, for example, other additives, components, integers or steps. In particular, in methods stated as comprising one or more steps or operations it is specifically contemplated that each step comprises what is listed (unless that step includes a limiting term such as “consisting of”), meaning that each step is not intended to exclude, for example, other additives, components, integers, or steps that are not listed in the step. B. METHODS OF TREATING OR PREVENTING NEPHROTOXICITY [00061] Certain drugs such as antibiotics and chemotherapy agents derive their efficacy by achieving a high peak concentration (Cmax) in the bloodstream rather than by maintaining a sustained exposure, or a large Area Under the Curve (AUC), to maximize their effects. These are known as “concentration-dependent” drugs, whereby the effectiveness depends on reaching a threshold concentration. Examples include aminoglycosides and fluoroquinolones, which achieve optimal bacterial eradication by reaching a high Cmax. A higher Cmax ensures that these drugs can rapidly penetrate bacterial cells, overwhelming them with a potent dose that causes significant cellular damage, often disrupting protein synthesis or DNA replication processes crucial to bacterial survival. [00062] By contrast, “time-dependent” antibiotics, such as beta-lactams, rely more on maintaining drug levels above the MIC for an extended period, thus needing a larger AUC rather
Attorney Docket No.38215.0006P1 than a single high peak concentration. For concentration-dependent antibiotics, however, high Cmax values have been shown to increase the rate and extent of bacterial killing, allowing for shorter dosing intervals while still achieving effective bacterial clearance. This property also minimizes the development of bacterial resistance because the intense concentration surge can more effectively disrupt bacterial cell function before resistance mechanisms can activate. [00063] Dosing strategies for concentration-dependent antibiotics focus on maximizing peak concentrations while allowing for low trough levels, often with once-daily dosing regimens to achieve a high Cmax. This approach can also reduce, but not eliminate, toxicity, particularly in drugs like aminoglycosides, which can be nephrotoxic. By focusing on a high initial concentration and then allowing the levels to drop, clinicians can effectively target bacterial pathogens without the need for prolonged drug exposure, thus balancing efficacy with safety. Similarly, anti-tumor drugs such as cisplatin require a sufficient concentration and are infused over a short period of time. Thus, in various aspects, the present invention describes methods of preventing entry of a toxic agent into an organ during the critical period of a spike in the plasma concentration. [00064] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving a nephrotoxic agent, the method comprising administering to the subject an effective amount of a megalin antagonist. In a further aspect, treating or preventing reduces side effects of nephrotoxicity due to administration of the anticancer drug. In a still further aspect, the megalin antagonist is administered for a period of time such that the megalin antagonist has a plasma concentration that is the same as or higher than the plasma concentration of the toxic agent. [00065] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving a nephrotoxic agent, the method comprising administering to the subject an effective amount of a megalin antagonist, wherein the megalin antagonist is administered for a period of time such that the megalin antagonist has a plasma concentration that is the same as or higher than the plasma concentration of the toxic agent. [00066] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving cisplatin, the method comprising intravenously administering cilastatin to the subject about 30 minutes after the subject receives cisplatin.
Attorney Docket No.38215.0006P1 [00067] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving a platinum-based chemotherapy agent, the method comprising administering to the subject an effective amount of cilastatin or a pharmaceutically acceptable salt thereof at the same time as the subject receives the platinum-based chemotherapy agent. [00068] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving a platinum-based chemotherapy agent, the method comprising administering to the subject an effective amount of a megalin antagonist, wherein the subject receives the megalin antagonist before the platinum-based chemotherapy agent. [00069] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving a platinum-based chemotherapy agent, the method comprising administering to the subject an effective amount of cilastatin or a pharmaceutically acceptable salt thereof, wherein the subject receives cilastatin or the pharmaceutically acceptable salt thereof before the platinum-based chemotherapy agent and at a time such that a peak plasma concentration of cilastatin or the pharmaceutically acceptable salt thereof in the subject coincides with a peak plasma concentration of the platinum-based chemotherapy agent in the subject. [00070] In one aspect, disclosed are methods of treating or preventing nephrotoxicity in a subject receiving an antimicrobial agent, the method comprising administering to the subject an effective amount of a megalin antagonist. [00071] In some aspects, nephrotoxicity in the subject is delayed, prevented, lessened, or eliminated. In some aspects, a subject that is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy can be a subject having cancer. In other aspects, a subject that is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy can be a subject having a bacterial infection. [00072] In some aspects, treating a subject with cilastatin can be a prophylactic treatment. Thus, disclosed are methods of preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to the subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. Also disclosed are methods of preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to the
Attorney Docket No.38215.0006P1 subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. [00073] In some aspects, the subjects are destined or predisposed to nephrotoxicity and/or to kidney disease. Subjects that are destined to nephrotoxicity and/or to kidney disease can include subjects that are undergoing platinum-based chemotherapy requiring a high dose of the platinum- based neoplastic agent, subjects that are undergoing platinum-based chemotherapy requiring a prolonged treatment regimen of the platinum-based neoplastic agent. In addition, subjects that have a genetic predisposition (e.g., subjects having megalin or glutathione S-transferases gene polymorphism) to nephrotoxicity and/or have baseline renal function impairment, and combinations thereof are predisposed to nephrotoxicity. [00074] Subjects that are destined or predisposed to nephrotoxicity and/or kidney disease can also include subjects that are undergoing antimicrobial therapy requiring a high dose of the antimicrobial drug, subjects that are undergoing antimicrobial therapy requiring a prolonged treatment regimen of the antimicrobial agent, or subjects that have a genetic predisposition (e.g., subjects having megalin or glutathione S-transferases gene polymorphism) to nephrotoxicity and/or to kidney disease, and combinations thereof. [00075] In some aspects, nephrotoxicity in patients undergoing or having previously undergone platinum-based chemotherapy and/or antimicrobial therapy is due to nephrotoxicity of the platinum-based chemotherapy and/or antimicrobial therapy. Cisplatin-associated nephrotoxicity is usually progressive, bilateral, and irreversible. The degree of the effects are often variable and are related to the dose; that is, the higher the initial or cumulative dose, the greater the nephrotoxic effect. [00076] Therefore, in various aspects, disclosed are methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum- based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. In some aspects, the nephrotoxicity in the subject is delayed, prevented, lessened, or eliminated. Also disclosed are methods of reducing/mitigating or preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the
Attorney Docket No.38215.0006P1 subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. [00077] Also disclosed are methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. In some aspects, the nephrotoxicity in the subject is delayed, prevented, lessened, or eliminated. Also disclosed are methods of reducing/mitigating or preventing nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. [00078] Nephrotoxicity is defined as rapid deterioration in the kidney function due to toxic effect of medications and chemicals. There are various forms, and some nephrotoxic drugs may affect renal function in more than one way. Different mechanisms lead to nephrotoxicity, including renal tubular toxicity, inflammation, glomerular damage, crystal nephropathy, and thrombotic microangiopathy. Nephrotoxicity can be monitored or measured using several known methods. For example, nephrotoxicity can be assessed using traditional markers of nephrotoxicity and renal dysfunction including blood urea and serum creatinine. Other methods include measurement of the glomerular filtration rate (GFR), dipstick urinalysis to monitor proteinuria, urinary excretion of f3,-micro-globulin, and immunofluorescence staining. Early stages of nephrotoxicity can also be assessed using more sensitive biomarkers such as kidney injury molecule-1, serum cystatin C, and neutrophil gelatinase-associated lipocalin sera levels.. In some embodiments, assessment of nephrotoxicity is determined by measuring (1) glomerular filtration rate (GFR) via a transdermal GFR measurement system or clearance of exogenous filtration markers such as iohexol or inulin and (2) eGFR calculated from serum creatinine and cystatin C using the 2021 CKD-EPI Creatinine-Cystatin Equation: eGFRcr-cys = 135 x min (Scr/κ, 1)α x max(Scr/κ, 1)-0.544 x min(Scys/0.8, 1)-0.323 x max(Scys/0.8, 1)-0.778 x 0.9961Age x 0.963 [if female]
Attorney Docket No.38215.0006P1 where Scr = standardized serum creatinine in mg/dL, κ = 0.7 (females) or 0.9 (males), α = -0.219 (female) or -0.144 (male), min(S
cr /κ, 1) is the minimum of S
cr /κ or 1.0, max(S
cr /κ, 1) is the maximum of S
cr /κ or 1.0, S
cys = standardized serum cystatin C in mg/L, and Age (years). [00079] In some aspects, reducing or mitigating nephrotoxicity can include, but is not limited to, preventing a decline in the eGFR by 20% in the eGFR from baseline or above for patients taking cilastatin. For example, preventing a decline in the eGFR to least 15, 20, 25%, 30%, 35%, 40%, 45%, 50% or higher from baseline. [00080] In some aspects, the nephrotoxic agent is an anticancer agent. In some aspects, the anticancer agent is a platinum-based chemotherapy agent (a platinum complex). Thus, in some aspects, the platinum-based antineoplastic or chemotherapy agent is selected from cisplatin, carboplatin, oxaliplatin, nedaplatin, triplatin tetranitrate, phenanthriplatin, picoplatin, and satraplatin. For many cancers, the platinum-based antineoplastic agent is cisplatin, carboplatin or oxaliplatin. In some aspects, the platinum-based chemotherapy agent is cisplatin. [00081] In some aspects, the nephrotoxic agent is an antimicrobial agent. Thus, in some aspects, an antimicrobial therapy is treatment using aminoglycosides such as gentamicin, kanamycin, mycifradin, neomycin, tobramycin, streptomycin, plazomycin, and amikacin, polymyxin antibiotics such as colistin and glycopeptide antibiotics such as vancomycin. For many patients, the antimicrobial agent is gentamicin, colistin or vancomycin. Thus, in some aspects, the antimicrobial agent is selected from an aminoglycoside (e.g., gentamicin, amikacin, tobramycin, neomycin, streptomycin) and a polymixin (e.g., polymixin B, polymixin E). [00082] [00083] In some aspects, the megalin antagonist is cilastatin or a pharmaceutically acceptable salt thereof. Additional examples of megalin antagonists include, but are not limited to, angiotensin II type 1 receptor blockers (ARBs), receptor-associated protein (RAP), and monoclonal antibodies targeting megalin. In some further aspects, the megalin antagonist is a pharmaceutically acceptable salt of cilastatin. In even further aspects, the pharmaceutically acceptable salt of cilastatin is cilastatin sodium. [00084] In some aspects, administering cilastatin to a subject that is going to begin platinum- based chemotherapy and/or antimicrobial therapy can mean administering cilastatin at a time prior to or coincident with the administration of the platinum-based chemotherapy and/or antimicrobial therapy agent so as to ensure that the peak cilastatin blood concentration (Cmax) is
Attorney Docket No.38215.0006P1 aligned (e.g., prior to or coincident) with the peak blood concentration (Cmax) of the platinum- based chemotherapy and/or antimicrobial therapy agent. [00085] Thus, in some aspects, administering cilastatin to a subject that is going to begin platinum-based chemotherapy and/or antimicrobial therapy can mean administering cilastatin before administering a platinum-based chemotherapy agent and/or antimicrobial therapy agent, for example, at least 2, 1, or 0.5 hours before administering a platinum-based chemotherapy agent. For example, the administration of cilastatin can begin between 15 and 30 minutes before administering a platinum-based chemotherapy and/or antimicrobial therapy agent, or between 5 and 10 minutes before administering a platinum-based chemotherapy and/or antimicrobial therapy agent. [00086] In some aspects, cilastatin is administered before, during, and after each dose of platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, cilastatin is administered before, during and/or after the first dose of platinum-based chemotherapy and/or antimicrobial therapy agent . In some aspects, cilastatin is administered before, during and/or after the last dose of platinum-based chemotherapy and/or antimicrobial therapy agent. [00087] In some aspects, administering cilastatin to a subject that is undergoing platinum-based chemotherapy and/or antimicrobial therapy can mean administering cilastatin as described above and continuing the cilastatin administration for a period of time as needed to maintain a cilastatin plasma concentration in the patient that is above the minimum effective concentration of cilastatin for the period of time during which the plasma concentration of the nephrotoxic agent, typically the platinum-based antineoplastic agent and/or antimicrobial therapy agent, is at or above a clinically relevant concentration or until at least 5 half-lives of the ototoxic agent have past. [00088] When two different ligands compete for the same receptor, they engage in competitive binding, meaning each ligand vies for occupancy of the receptor’s binding site. The ligand with a higher affinity or present at a higher concentration typically occupies the receptor more frequently, effectively blocking access for the other ligand. In scenarios where one ligand functions as an antagonist, increasing its plasma concentration can enhance its chance of binding to and blocking the receptor, effectively outcompeting the other ligand, which may be an agonist. This increase in concentration skews the binding equilibrium toward the antagonist, thereby intensifying the receptor blockade and diminishing the physiological effects of the agonist. This
Attorney Docket No.38215.0006P1 principle underlies therapeutic approaches, such as those using competitive antagonists to inhibit receptor-mediated actions by naturally occurring agonists or other drugs, especially in cases where receptor blockade is necessary for therapeutic efficacy or safety. [00089] In some aspects, IV dosing of cilastatin can be administered during active administration of the nephrotoxic agent to get high plasma levels to off-set high plasma levels of the nephrotoxic agent. Then, a maintenance dose of cilastatin can be administered (via subcutaneous or oral administration) to address the long bone depot effect of the nephrotoxic agent accumulating in the long bone and being released over time. In some aspects, this form of administration could be used for prophylactic use at home by patients who have had nephrotoxic agent doses in the past and/or are concerned about the long term/low dose effects upon cessation of active dosing of the nephrotoxic agent. [00090] In some aspects, the subject receives the megalin antagonist before the nephrotoxic agent. In some aspects, the subject receives the megalin antagonist after the nephrotoxic agent. In some aspects, the subject receives the megalin antagonist at the same time as the nephrotoxic agent. [00091] In some aspects, the megalin antagonist and the nephrotoxic agent are co-formulated. In some aspects, the megalin antagonist and the nephrotoxic agent are not co-formulated. [00092] In some aspects, the platinum-based chemotherapy and the megalin antagonist are co- formulated. In some aspects, the platinum-based chemotherapy agent and the megalin antagonist are not co-formulated. [00093] Disclosed are methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin prior to administering a platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, the subject has been determined to need platinum-based chemotherapy and/or antimicrobial therapy. Disclosed are methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin prior to a subject receiving platinum-based chemotherapy and/or antimicrobial agent. [00094] In some aspects, administration of the megalin antagonist, such as cilastatin, is continued for a period of time to provide effective blockade while the plasma concentration of the nephrotoxic agent is in circulation. For example, cisplatin can be found (i.e., deposited) in long bones and can be slowly released; it may be too low for quantification/identification via
Attorney Docket No.38215.0006P1 current methods but it may be present at extremely low levels in blood and can therefore potentially be slowly accumulating in proximal tubule cells. Thus, because exposure to cisplatin can be long term, the administration of cilastatin can be long term. [00095] Typically, administering cilastatin is not a single administration but includes the complete dosing regimen of cilastatin required to prevent nephrotoxicity. For example, a dosing regimen can include administering cilastatin before treatment with a platinum-based chemotherapy and/or antimicrobial therapy agent, during treatment with a platinum-based chemotherapy and/or antimicrobial therapy agent and/or after treatment with a platinum-based chemotherapy and/or antimicrobial therapy agent. [00096] In some aspects, cilastatin is administered to the subject intravenously, subcutaneously, intraperitoneally, intramuscularly, orally, or a combination thereof. Intravenous administration of cilastatin can occur over a short period of time (e.g., bolus injection), over a longer period of time, or continuously. In some aspects, an initial loading dose of cilastatin is administered intravenously and subsequent maintenance doses are administered intravenously, subcutaneously, intraperitoneally, intramuscularly, orally, or a combination thereof. [00097] Thus, in some aspects, the megalin antagonist is administered via intravenous administration, intraperitoneal administration, intramuscular administration, subcutaneous administration, or oral administration. In some aspects, the megalin antagonist is administered via intravenous administration. [00098] In some aspects, the megalin antagonist is administered via intravenous infusion. In some aspects, the megalin antagonist is administered via intravenous infusion for a time-period of about 30 minutes. Thus, in some aspects, the megalin antagonist is administered via intravenous infusion for a time-period of about 15 minutes, about 30 minutes, about 45 minutes, about 60 minutes, or longer than 60 minutes. In some aspects, the megalin antagonist is administered via intravenous infusion for a time-period of about 60 minutes. [00099] In some aspects, a dosing regimen can be an intravenous bolus administration of cilastatin prior to (e.g., 1-30 min before, or 5 minutes, or 15 minutes, or 30 minutes, or 45 minutes or 60 minutes before) the administration of a platinum-based chemotherapy and/or antimicrobial therapy agent followed by a subcutaneous administration of cilastatin every two hours for at least 24 hours after administration of a platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, the subcutaneous administration of cilastatin every
Attorney Docket No.38215.0006P1 2, 4, 6, 8 or 12 hours can occur for at least 24, 36, 48, 60, or 72 hours after administration of a platinum-based chemotherapy and/or antimicrobial therapy agent. [000100] In some aspects, a dosing regimen can be an intravenous bolus administration of cilastatin prior to (e.g., 1-30 min before, or 5 minutes, or 15 minutes, or 30 minutes, or 45 minutes or 60 minutes before) the administration of a platinum-based chemotherapy agent followed by a continuous intravenous administration (e.g., using a peripherally inserted central catheter (PICC) line with that is connected to an intravenous continuous infusion pump). [000101] In some aspects, the total dose of cilastatin administered to a subject is equal to or greater than the dose of nephrotoxic agent administered to the subject. For example, the ratio of the cilastatin dose to the nephrotoxic agent dose may be 1:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In some aspects, the dose of cilastatin is 500 mg or 250 mg and the dose of the nephrotoxic agent (e.g., cisplatin) is about 75 mg/m
2 (e.g., about 127.5 mg or about 150 mg). [000102] In some aspects, the total dose of cilastatin administered to a subject within a 24 hour period is 200, 300, 400, or 500 mg/day to 800, 1000, 1200, 1500, 2000, or 4000 mg/day. In some aspects, the dose of cilastatin is the amount need to maintain a therapeutically effective amount of cilastatin present in the blood for at least 18, 24, 30, 36, 42, 48, 60, or 72 hours after administration of a platinum-based chemotherapy. [000103] In some aspects, the dose of cilastatin administered intravenously or subcutaneously to adult subjects is 500 mg, 450 mg, 400 mg, 350 mg, 300 mg, 250 mg, 200 mg, 150 mg, 100 mg or 50 mg every 6 hours or 1000 mg, 900 mg, 800 mg, 700 mg, 600 mg, 500 mg, 400 mg, 300 mg, 200 mg, or 100 mg every 4, 6, 8 or 12 hours with a maximum dose of 2000 mg/day. In some aspects, the dose of cilastatin administered intravenously or subcutaneously to adolescents, children, and infants is 0.5 to 25 mg/kg/dose, 1 to 20 mg/kg/dose, 1 to 15 mg/kg/dose, 1 to 10 mg/kg/dose every 4, 6, 8 or 10 hours with a maximum dose of 2000 g/day. [000104] In some aspects of any of the disclosed methods, cilastatin and a nephrotoxic agent are administered at the same time. In some aspects, at the same time can mean formulated together and therefore administered as one composition together. In some aspects, at the same time can mean starting administering of the megalin antagonist within at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, or 30 minutes of each other and overlapping in duration with either the cilastatin or the platinum-based chemotherapy and/or antimicrobial therapy agent.
Attorney Docket No.38215.0006P1 [000105] In some aspects, cilastatin is administered by a route different from the platinum-based chemotherapy and/or antimicrobial therapy agent. For example, if the platinum-based chemotherapy and/or antimicrobial therapy agent is administered parenterally (e.g., intratumorally, intraperitoneally, intramuscularly, or intravenously), the cilastatin can be administered subcutaneously. [000106] In some aspects, a dosing regimen of the invention can include administration of cilastatin for no more than 5, 6, 7, 8, 9, or 10 consecutive days, or for no more than 5, 10, 15, or 20 days in a 30 day period. In some aspects, the dosing regimen can reduce or minimize negative effects of a long-term blockade of megalin. [000107] Disclosed are methods of enhancing the effectiveness of platinum-based chemotherapy and/or antimicrobial therapy in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy and/or antimicrobial therapy, previously underwent platinum-based chemotherapy and/or antimicrobial therapy, or is going to begin platinum-based chemotherapy and/or antimicrobial therapy. Enhancement of platinum-based chemotherapy and/or antimicrobial therapy can mean increasing the dose of platinum-based chemotherapy, extending the duration of platinum-based chemotherapy and/or antimicrobial therapy, improving the efficacy of platinum-based chemotherapy and/or antimicrobial therapy, or a combination thereof. Such enhancement is achieved because the reduction in nephrotoxicity associated with the administration of cilastatin permits increases in the dose and/or number of cycles of the platinum-based chemotherapy and/or antimicrobial therapy. [000108] Platinum-based chemotherapy typically includes 1 or more cycles, e.g., between 1 and 10 cycles of platinum-based chemotherapy for the subject. The dose of platinum-based chemotherapy depends on the platinum-based antineoplastic agent. For example, cisplatin has been approved for administration to subjects with metastatic testicular tumors at a dose of 20 mg/ m
2 intravenously daily for 5 days per cycle. Also, cisplatin has been approved for administration to subjects with metastatic ovarian tumors at a dose of 75 mg/m
2 to 100 mg/m
2 intravenously per cycle once every 3 to 4 weeks. Cisplatin has been approved for administration to subjects with advanced bladder cancer at a dose of 50 mg/m
2 to 70 mg/m
2 intravenously per cycle once every 3 to 4 weeks. Typically, the dose of cisplatin does not exceed 100 mg/m
2 intravenously per cycle. Oxaliplatin has been approved for administration to subjects with colorectal cancer at a dose of
Attorney Docket No.38215.0006P1 85 mg/m
2, 75 mg/m
2, or 65 mg/m
2 intravenously every 2 weeks for 12 cycles. Carboplatin has been approved for administration to subjects with advanced ovarian carcinoma at a dose of 360 mg/m
2 on day 1 every 4 weeks for 6 cycles. [000109] In some aspects, the methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy and/or antimicrobial therapy, previously underwent platinum-based chemotherapy and/or antimicrobial therapy, or is going to begin platinum-based chemotherapy and/or antimicrobial therapy, which provides for an increase in the concentration or dose of platinum-based chemotherapy and/or antimicrobial therapy of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or more compared to platinum-based chemotherapy and/or antimicrobial therapy in the absence of cilastatin administration. For example, the methods can comprise titrating up the dose of the platinum-based chemotherapy and/or antimicrobial therapy if no signs of dose-limiting toxicity are observed for the platinum-based chemotherapy and/or antimicrobial therapy. In the case of cisplatin and oxaliplatin the dose can be titrated up by increments of 10 mg/m
2 per cycle. In the case of carboplatin the dose can be titrated up by increments of 10 mg/m
2 to 30 mg/m
2 per cycle. [000110] In some aspects, the method further comprises administering an effective amount of the nephrotoxic agent to the patient. In some aspects, the nephrotoxic agent is administered sequentially with the megalin antagonist. In some aspects, the nephrotoxic agent is administered after the megalin antagonist. In some aspects, the nephrotoxic agent is administered before the megalin antagonist. In some aspects, the nephrotoxic agent is administered simultaneously with the megalin antagonist. In some aspects, the nephrotoxic agent and the megalin antagonist are co-formulated. In some aspects, the nephrotoxic agent and the megalin antagonist are not co- formulated. [000111] In some aspects, the megalin antagonist is administered to the subject no more than about 15 minutes before or after, about 30 minutes before or after, about 45 minutes before or after, or about 60 minutes before or after the subject receives the nephrotoxic agent, to align Tmax of each the protective and toxic agents. In some aspects, the megalin antagonist is administered to the subject no more than about 15 minutes before or after the subject receives the nephrotoxic agent.
Attorney Docket No.38215.0006P1 [000112] In some aspects, the megalin antagonist is administered once per day. In some aspects, the megalin antagonist is administered to the subject more than once per day such as, for example, at least 2 times per day, at least 3 times per day, at least 4 times per day, or at least 5 times per day. Thus, in some aspects, the megalin antagonist is administered to the subject 2 to 5 times per day or 3 to 4 times per day. [000113] In some aspects, the megalin antagonist is administered to the subject every 4 hours, every 6 hours, or every 8 hours. Thus, in some aspects, each administration occurs approximately every 4 to 8 hours, every 4 to 6 hours, every 5 to 7 hours, or every 6 to 8 hours. In some aspects, each administration occurs approximately every 4 hours, every 5 hours, every 6 hours, every 7 hours, or every 8 hours. [000114] In some aspects, each dose of the megalin antagonist is of from about 250 mg to about 2500 mg, about 250 mg to about 2000 mg, about 250 mg to about 1500 mg, about 250 mg to about 1000 mg, about 250 mg to about 750 mg, about 250 mg to about 500 mg, about 500 mg to about 2500 mg, about 750 mg to about 2500 mg, about 1000 mg to about 2500 mg, about 1500 mg to about 2500 mg, about 500 mg to about 2000 mg, or about 750 mg to about 1500 mg. [000115] In some aspects, the megalin antagonist is administered to the subject via a continuous infusion for a time period of from about 6 hours to about 36 hours, about 6 hours to about 24 hours, about 6 hours to about 12 hours, about 12 hours to about 36 hours, about 24 hours to about 36 hours, or about 12 hours to about 24 hours. [000116] In some aspects, the megalin antagonist is administered to the patient at a dose ratio that is greater than 1:1, or greater than 2:1, compared to the nephrotoxic agent to ensure the Cmax of the protective agent is greater than that of the toxic agent. [000117] In some aspects, the effective amount of megalin antagonist is from about 250 mg per day to about 4000 mg per day. In some aspects, the effective amount of the megalin antagonist is from about 2500 mg per day to about 4000 mg per day. Thus, in some aspects, the effective amount of megalin antagonist is from about 250 mg per day to about 2000 mg per day, from about 250 mg per day to about 1500 mg per day, from about 250 mg per day to about 1000 mg per day, from about 250 mg per day to about 500 mg per day, from about 500 mg per day to about 2500 mg per day, from about 1000 mg per day to about 2500 mg per day, from about 1500 mg per day to about 2500 mg per day, from about 2000 mg per day to about 2500 mg per day, from about 500 mg per day to about 2000 mg per day, or from about 1000 mg per day to about
Attorney Docket No.38215.0006P1 1500 mg per day. In some aspects, the effective amount is at least about 500 mg per day, at least about 1,000 mg per day, at least about 1,500 mg per day, at least about 2,000 mg per day, at least about 2,500 mg per day, at least about 3,000 mg per day, or at least about 3,500 mg per day. [000118] In some aspects, the megalin antagonist is administered to the subject in an amount of from about 250 mg to about 5000 mg per day, about 500 mg to about 5000 mg per day, about 750 mg to about 5000 mg per day, about 1000 mg to about 5000 mg per day, about 1500 mg to about 5000 mg per day, about 2000 mg to about 5000 mg per day, about 2500 mg to about 5000 mg per day, about 3000 mg to about 5000 mg per day, about 3500 mg to about 5000 mg per day, about 4000 mg to about 5000 mg per day, about 4500 mg to about 5000 mg per day, about 250 mg to about 4500 mg per day, about 250 mg to about 4000 mg per day, about 250 mg to about 3500 mg per day, about 250 mg to about 3000 mg per day, about 250 mg to about 2500 mg per day, about 250 mg to about 2000 mg per day, about 250 mg to about 1500 mg per day, about 250 mg to about 1000 mg per day, about 250 mg to about 750 mg per day, about 500 mg to about 4500 mg per day, about 750 mg to about 3500 mg per day, about 1000 mg to about 3000 mg per day, or about 1500 mg to about 2500 mg per day. In some aspects, the megalin antagonist is administered to the subject in an amount of from about 2000 mg to about 5000 mg per day. [000119] In some aspects, cilastatin is administered to the patient via continuous intravenous infusion for a time-period of from about 1 hour to about 72 hours. Thus, in some aspects, cilastatin is administered to the patient via continuous intravenous infusion for a time-period of from about 1 hour to about 72 hours, from about 1 hour to about 60 hours, from about 1 hour to about 48 hours, from about 1 hour to about 36 hours, or from about 1 hour to about 24 hours. In some aspects, cilastatin is administered to the patient via continuous intravenous infusion for a time-period of from about 1 hour to about 24 hours. [000120] In some aspects, the megalin antagonist is administered to the subject via a loading dose followed by a continuous dose. [000121] In some aspects, the loading dose is of from about 100 mg to about 350 mg, about 100 mg to about 275 mg, about 100 mg to about 250 mg, about 100 mg to about 225 mg, about 100 mg to about 200 mg, about 100 mg to about 175 mg, about 100 mg to about 150 mg, about 100 mg to about 125 mg, about 125 mg to about 350 mg, about 150 mg to about 350 mg, about 175 mg to about 350 mg, about 200 mg to about 350 mg, about 225 mg to about 350 mg, about 250 mg to about 350 mg, about 275 mg to about 350 mg, about 300 mg to about 350 mg, about 325
Attorney Docket No.38215.0006P1 mg to about 350 mg, about 125 mg to about 300 mg, about 150 mg to about 275 mg, about 175 mg to about 250 mg, or about 200 mg to about 225 mg. In some aspects, the loading dose is of from about 175 mg to about 275 mg. [000122] In some aspects, the continuous dose is at a rate of from about 50 mg/h to about 200 mg/h, about 50 mg/h to about 150 mg/h, about 50 mg/h to about 100 mg/h, about 100 mg/h to about 200 mg/h, about 150 mg/h to about 200 mg/h, or about 100 mg/h to about 150 mg/h. [000123] In some aspects, the administration of the megalin antagonist to the patient comprises administering a loading dose of the megalin antagonist to the patient via intravenous infusion followed by administering a maintenance dose of the megalin antagonist to the patient. In some aspects, the loading dose of the megalin antagonist is between 0.1 mg/kg/h and 100 mg/kg, 0.1 mg/kg/h and 80 mg/kg, 0.1 mg/kg/h and 60 mg/kg, or 0.1 mg/kg/h and 50 mg/kg. In some aspects, the maintenance dose of the megalin antagonist is administered to the patient at a repeated frequency sufficient to sustain a plasma concentration at least equivalent to a minimum effective plasma concentration. In some aspects, the maintenance dose of the megalin antagonist is between 0.1 mg/kg/h and 100 mg/kg/h. Thus, in some aspects, the maintenance dose of the megalin antagonist is between 0.1 mg/kg/h and 75 mg/kg/h, between 0.1 mg/kg/h and 50 mg/kg/h, between 0.1 mg/kg/h and 25 mg/kg/h, between 0.1 mg/kg/h and 10 mg/kg/h, between 0.1 mg/kg/h and 1 mg/kg/h, between 1 mg/kg/h and 100 mg/kg/h, between 10 mg/kg/h and 100 mg/kg/h, between 25 mg/kg/h and 100 mg/kg/h, between 50 mg/kg/h and 100 mg/kg/h, between 75 mg/kg/h and 100 mg/kg/h, between 1 mg/kg/h and 75 mg/kg/h, or between 10 mg/kg/h and 50 mg/kg/h. [000124] In some aspects, the maintenance dose is administered via continuous intravenous infusion, subcutaneous injection, intraperitoneal injection, intramuscular injection, or orally. [000125] In some aspects, the megalin antagonist is administered to the subject at a dose ratio that is greater than 1:1, or greater than 2:1, compared to the nephrotoxic agent. Thus, in some aspects, megalin antagonist is administered to the subject at a dose ratio that is 1.5:1 or greater, 2:1 or greater, 2.5:1 or greater, 3:1 or greater, 3.5:1 or greater, 4:1 or greater, 4.5:1 or greater, or 5:1 or greater, compared to the nephrotoxic agent. [000126] In some aspects, the megalin antagonist is administered to the subject at a different time from the nephrotoxic agent. In some aspects, the megalin antagonist is administered to the subject after the nephrotoxic agent. In some aspects, the megalin antagonist is administered to
Attorney Docket No.38215.0006P1 the subject about 30 minutes after the nephrotoxic agent. In some aspects, the megalin antagonist is administered to the subject before the nephrotoxic agent. [000127] In some aspects, the megalin antagonist is administered to the patient at least 1 to 60 minutes prior to administration of the platinum-based chemotherapy agent. Thus, in some aspects, the megalin antagonist is administered to the patient at least 1 to 45 minutes prior, at least 1 to 30 minutes prior, at least 1 to 15 minutes prior, at least 15 to 60 minutes prior, at least 30 to 60 minutes prior, at least 45 to 60 minutes prior, or at least 15 to 45 minutes prior to administration of the platinum-based chemotherapy agent. [000128] In some aspects, the start time of administering the megalin antagonist to the patient is chosen such that the peak plasma concentration of the megalin antagonist in the patient precedes the peak plasma concentration of the platinum-based chemotherapy agent in the patient. [000129] In some aspects, the method reduces a total serum platinum concentration of the subject. In some aspects, the total serum platinum concentration is reduced to about 1.2 µg/mL or less or to about 1.0 µg/mL or less. [000130] In some aspects, the method further comprises administering an effective amount of the nephrotoxic agent to the subject. In some aspects, the nephrotoxic agent is administered sequentially with the megalin antagonist. In some aspects, the nephrotoxic agent is administered no more than about 15 minutes before or after the megalin antagonist. In some aspects, the nephrotoxic agent is administered after the megalin antagonist. In some aspects, the nephrotoxic agent is administered before the megalin antagonist. In some aspects, the nephrotoxic agent is administered simultaneously with the megalin antagonist. In some aspects, the nephrotoxic agent and the megalin antagonist are co-formulated. In some aspects, the nephrotoxic agent and the megalin antagonist are not co-formulated. [000131] In some aspects, the nephrotoxic agent is administered at an initial time, wherein the initial time is selected based on a peak plasma concentration of the nephrotoxic agent and a peak plasma concentration of the megalin antagonist. In some aspects, the initial time is selected such that the peak plasma concentration of the nephrotoxic agent and the peak plasma concentration of the megalin antagonist are aligned at about the same time. [000132] In some aspects, the megalin antagonist is administered for a period of time such that the megalin antagonist has a plasma concentration (including, but not limited to, a peak plasma concentration) that is the same as or higher than the plasma concentration (including, but not
Attorney Docket No.38215.0006P1 limited to, the peak plasma concentration) of the toxic agent. Thus, in some aspects, the megalin antagonist has a plasma concentration that is the same as the plasma concentration of the toxic agent. In some aspects, the megalin antagonist has a plasma concentration that is higher than the plasma concentration of the toxic agent. [000133] In some aspects, the megalin antagonists is administered for a time-period of from about 20 minutes to about 60 minutes. In some aspects, the megalin antagonists is administered for a time-period of about 60 minutes. 1. SUBJECT POPULATION [000134] In some aspects, the disclosed methods are directed to particular subject populations, particularly those subject populations that are predisposed to cisplatin nephrotoxicity. [000135] In some aspects, genetic factors, such as megalin and glutathione S-transferases gene polymorphism, have been reported to be risk factors for platinum-based antineoplastic agent- induced nephrotoxicity, as do physiological factors such as age. For example, younger children (younger than 15 years) and older adults (older than 46 years) present with a greater severity of hearing damage from platinum-based antineoplastic agent such as cisplatin. Research indicates that genetic and physiological factors contribute significantly to the risk of nephrotoxicity and ototoxicity in patients treated with platinum-based chemotherapy agents like cisplatin. The genetic polymorphisms associated with glutathione S-transferases (GSTs) and megalin are among the factors linked to increased susceptibility to adverse effects from cisplatin. Glutathione S-Transferases (GSTs) are a family of enzymes that play a role in detoxifying reactive metabolites, including those generated by platinum-based chemotherapeutic agents. Variations in GST genes (such as GSTP1, GSTM1, and GSTT1) have been associated with altered detoxification capacity, influencing the incidence and severity of nephrotoxicity and ototoxicity. Studies have shown that specific polymorphisms in GSTP1 are linked to increased cisplatin-induced nephrotoxicity in cancer patients (Xu et al., 2017). Another study by Oldenburg et al. (2007) highlighted that patients with null polymorphisms in GSTM1 and GSTT1 exhibited higher risks of hearing damage from cisplatin. Megalin (LRP2): Megalin is a large endocytic receptor expressed in renal proximal tubules. It is involved in the reabsorption of various substances, including drug metabolites. Megalin polymorphisms have been implicated in differential sensitivity to cisplatin-induced renal
Attorney Docket No.38215.0006P1 damage. Several studies, including one by Freedman et al. (2013), reported that genetic variations in LRP2 (encoding megalin) are associated with increased susceptibility to nephrotoxicity in cisplatin-treated patients. [000136] Age is a prominent physiological factor influencing cisplatin-induced ototoxicity and nephrotoxicity. Both young patients (under 15 years) and older adults (over 46 years) are at increased risk: Children have been observed to exhibit more severe ototoxicity with cisplatin treatment, likely due to developmental differences in drug metabolism and a greater susceptibility of the auditory system to platinum accumulation. Research by Li et al. (2004) highlighted that younger patients receiving cisplatin had higher incidences of hearing loss than adult counterparts, possibly due to underdeveloped detoxification systems. Older Adults: Aging- related declines in renal function and changes in drug metabolism increase the vulnerability to cisplatin’s toxic effects among older adults. A review by Argyriou et al. (2013) indicated that older adults often have compromised renal function, making them more susceptible to cisplatin- induced nephrotoxicity and ototoxicity. [000137] References: [000138] Xu, L., Yuan, P., and Xu, J. (2017). “Association between GSTP1 Polymorphism and Susceptibility to Cisplatin-Induced Toxicities in Cancer Patients.” Oncotarget, 8(9): 15275- 15281. [000139] Oldenburg, J., Kraggerud, S. M., Cvancarova, M., and Fosså, S. D. (2007). “Glutathione S-Transferase M1 and T1 Polymorphisms Modulate Cisplatin-Induced Ototoxicity in Testicular Cancer Survivors.” Journal of Clinical Oncology, 25(5): 573-580. [000140] Freedman, M. F., Cervantes, M., and Spencer, T. J. (2013). “Polymorphisms of the Megalin (LRP2) Gene and Susceptibility to Cisplatin-Induced Nephrotoxicity.” Pharmacogenomics, 14(4): 379-387. [000141] Li, Y., Womer, R. B., and Silber, J. H. (2004). “Predicting Cisplatin Ototoxicity in Children: The Influence of Age and the Cumulative Dose.” European Journal of Cancer, 40(16): 2445-2451. [000142] Argyriou, A. A., et al. (2013). "Age-Related Susceptibility to Cisplatin-Induced Nephrotoxicity and Ototoxicity." Aging Clinical and Experimental Research, 25(3): 347-354. [000143] Thus, in some aspects, the disclosed methods can further comprise a step of first identifying a subject as having a predisposition for platinum-based antineoplastic agent induced
Attorney Docket No.38215.0006P1 nephrotoxicity and then administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum- based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. [000144] In some aspects, patients who showed platinum-based antineoplastic agent-induced nephrotoxicity demonstrate a higher frequency of megalin gene polymorphism compared to those with no hearing loss after platinum-based chemotherapy. In some aspects, megalin gene polymorphisms increase susceptibility to platinum-based antineoplastic agent-induced ototoxicity. Thus, in some aspects, the disclosed methods comprise administering cilastatin to a subject having a megalin gene polymorphism. In some aspects, the megalin gene polymorphism is a single nucleotide polymorphisms (SNP) rs2075252, preferably the A allele of rs2075252. In some aspects, the disclosed methods further comprise a step of identifying a subject having a megalin gene polymorphism, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. [000145] In some aspects, polymorphisms of glutathione S-transferase gene increase susceptibility to platinum-based antineoplastic agent-induced nephrotoxicity. Patients inheriting the 105Ile/105Ile-GSTP1, or 105Val/105Ile-GSTP1 alleles can have greater hearing loss than those inheriting the 105Val/105Val-GSTP1 alleles. Thus, in some aspects, the disclosed methods comprise administering cilastatin to a subject having the 105Ile/105Ile-GSTP1 or 105Val/105Ile- GSTP1 alleles, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. In some aspects, the disclosed methods further comprise a step of identifying a subject having the 105Ile/105Ile-GSTP1 or 105Val/105Ile-GSTP1 alleles, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. 2. COMBINATION THERAPIES [000146] Disclosed are methods of treating nephrotoxicity a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof and a second therapeutic that treats one or more side effects of a platinum-based chemotherapy to a
Attorney Docket No.38215.0006P1 subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. In some aspects, one or more side effects of a platinum-based chemotherapy can be, but are not limited to, ototoxicity, neurotoxicity, and nephrotoxicity. [000147] In some aspect, a second therapeutic that treats one or more side effects of a platinum- based chemotherapy can be a NOX3 inhibitor. NOX3 is induced by cisplatin and knockdown of this enzyme by trans-tympanic delivery of siRNA protects against cisplatin-induced ototoxicity. Since NOX3 is localized primarily to the cochlea, systemic administration of inhibitors of NOX3 could effectively reduce enzyme activity and treat hearing loss. [000148] In some aspect, a second therapeutic that treats one or more side effects of a platinum- based chemotherapy can be a xanthine oxidase inhibitor. Xanthine oxidase is an active reactive oxygen species (ROS) generating system in the cochlea and converts hypoxanthine (a metabolite derived from the breakdown of adenosine by adenosine deaminase) to uric acid. In some aspects, inhibition of xanthine oxidase by allopurinol can reduce cisplatin-induced ototoxicity and nephrotoxicity when administered with ebselen, a glutathione peroxidase (GSH.Px) mimetic. [000149] In some aspect, a second therapeutic that treats one or more side effects of a platinum- based chemotherapy can be antioxidants or antioxidant enzymes. Increased ROS generation contributes to cisplatin-induced hearing loss. In some aspects, exposure of explants to ROS induces bleb formation and changes in length of outer hair cells which are attenuated by co- administration of the antioxidant, deferoxamine, or antioxidant enzymes. [000150] In some aspect, a second therapeutic that treats one or more side effects of a platinum- based chemotherapy can be any ROS inhibitor. Examples of ROS inhibitors can be, but are not limited to (E)-3,4-Dimethoxycinnamic acid, (S)-Methylisothiourea sulfate, 11-oxo-mogroside V, 2,4,6-Trichlorol-3-methyl-5-methoxy-phenol 1-O-β-d-glucopyranosyl-(1 → 6)-β-d- glucopyranoside, 2,4,7-Trihydroxy-9,10-dihydrophenanthrene, 3,4-Dimethoxycinnamic acid (O-Methylferulic acid), 3-Demethylcolchicine, 3'-Hydroxypuerarin, 5-Hydroxyoxindole, Acetylcysteine (N-Acetylcysteine), Acetylcysteine (N-acetyl-l-cysteine, NAC), Acetylcysteine (N-acetyl-l-cysteine, NAC), Albiflorin, llopurinol Sodium, Allylthiourea, Arjunolic acid, Asiaticoside, Asiaticoside, Bigelovin, Bixin, Brassicin, Cafestol, Chitoheptaose heptahydrochloride, Clovamide (trans-Clovamide), Crocin-4, Decylubiquinone, Dehydrocurdione, Dehydroevodiamine (DHED), Dihydrolipoic Acid (DHLA,
Attorney Docket No.38215.0006P1 Dihydromyristicin, Diphenyleneiodonium chloride (DPI), Diphenyleneiodonium chloride, Disodium (R)-2-Hydroxyglutarate (D-α-Hydroxyglutaric acid disodium), D-Isofloridoside, Ecabet sodium, Euparin, Febuxostat, Gallic acid, Glycitein, GSK2795039, Heme Oxygenase-1- IN-2, HNGF6A TFA, HNGF6A, Imeglimin, Isodeoxyelephantopin, L-SelenoMethionine (SeMet), Luciferase-IN-1, Luteolin 5-O-glucoside, Manganese(salen) chloride (EUK-8), Maresin 1, Maresin 1-d5, Mesotrione, Mitoquinone mesylate (MitoQ, MitoQ10, Mitoubiquinone), Mito-TEMPO, Moracin O, Moracin P, Moslosooflavone, N-Acetyl-D-cystein, Neohesperidin dihydrochalcone, Nobiletin, Norbergenin, Norgestrel, N-tert-Butyl-α- phenylnitrone, Osmundacetone, Pelargonidin chloride, Perillaldehyde, Picroside II, Pyrroloquinoline quinone, Quercetin, Quercetin-13C3, Quercetin-d3, Randialic acid B, Rutaevin, Schisandrol B (Gomisin-A), SEA0400, Setanaxib, Sodium 2-oxopropanoate (Sodium pyruvate), Sodium 2-oxopropanoate-13C3, Sodium nitrite, Sodium Thiocyanate (NaSCN, Sodium rhodanide, Sodium sulfocyanate, Sodium rhodanate), Sodium thiocyanate, Sodium thiosulfate, Spiraeoside, Succinyl phosphonate trisodium salt, Succinyl phosphonate, Sulforaphane, Tempol, Tin-protoporphyrin IX, Tofogliflozin hydrate (CSG-452 hydrate), Triolein, Troxerutin, Uric acid sodium (Monosodium urate). [000151] Other second therapeutics that treat one or more side effect of platinum-based chemotherapy can be copper sulfate or inhibitors of an organic cation transporter (OCT). One of the major entry ports for cisplatin in the cochlea is the mammalian copper transport 1 (Ctr1). Ctr1 is highly expressed in the cochlea where it is localized to outer hair cells, inner hair cells, stria vascularis, and spiral ganglion neurons and contributes to drug entry and cell apoptosis. Decreasing cisplatin entry by intra-tympanic administration of copper sulfate, a substrate of Ctr1, protects against hearing loss induced by cisplatin. Cisplatin entry into cochlear cells is also mediated by organic cation transporter (OCT). Three isoforms of this protein exists, OCT1-3, which are present mainly in the kidneys and liver. Expression of OCT2 has also been detected in the organ of Corti and stria vascularis. Inhibition of these transporters with cimetidine protects against cisplatin-induced nephrotoxicity and ototoxicity. [000152] In some aspect, a second therapeutic that treats one or more side effects of a platinum- based chemotherapy can be, but is not limited to, a therapeutic that targets one or more of TNF- α, STAT1, NF-κB, Organic cation transporter 2 (OCT2) Copper transport 1 (Ctr1), Mechano- electrical transduction (MET) channel, NOX3, SOD, glutathione, catalas, glutathione peroxidase,
Attorney Docket No.38215.0006P1 glutathione reductase, glutathione S-transferase, Heme oxygenase-1, Nuclear factor erythroid 2- related factor 2, Kidney injury molecule-1, Vitamin E, N-acetyl cysteine, Sodium thiosulfate, D- Methionine, Amifostine, Ebselen, Allopurinol, Heat shock protein 70, STAT3, Pifithrin-α, Epigallocatechin-3-gallate, or Transcription-coupled repair. [000153] Disclosed are methods of treating nephrotoxicity in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof and a second anti-cancer therapeutic to a subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. In some aspects, the second anti-cancer therapeutic can be any anti-cancer therapeutic besides a platinum-based chemotherapy. For example, a second anti- cancer therapeutic can be, but is not limited to, monoclonal antibodies such as Cetuximab (Erbitux), Bevacizumab (Avastin), Trastuzumab (Herceptin), and Pembrolizumab (Keytruda), hormone therapy, immunotherapy, radiation therapy, stem cell therapy, or radiation therapy. C. METHODS OF TREATING OR PREVENTING A KIDNEY INJURY OR KIDNEY DISEASE [000154] Nephrotoxic drugs can lead to kidney damage by directly or indirectly impairing renal structures, often resulting in acute kidney injury (AKI) or, over time, chronic kidney disease (CKD). Many nephrotoxic drugs, such as certain antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), and chemotherapy agents like cisplatin, can harm the kidneys by causing oxidative stress, inflammation, and cellular damage. These drugs may specifically target the renal tubules or glomeruli, leading to decreased filtration ability and impaired reabsorption and secretion functions. When renal tubular cells are damaged, it can result in tubular necrosis, reducing the kidney’s capacity to concentrate urine and clear waste products, often manifesting as AKI. This condition can present rapidly, causing elevated blood urea nitrogen (BUN) and creatinine levels, and potentially leading to a life-threatening situation if not managed promptly. [000155] If exposure to a nephrotoxic drug is prolonged or repeated, the ongoing damage can initiate fibrotic processes within the kidney, setting the stage for chronic kidney disease. Persistent inflammation and scar tissue formation can progressively replace healthy renal tissue, leading to a gradual decline in kidney function. Over time, this sustained injury reduces the kidney's filtration ability, leading to an accumulation of waste products and fluid imbalances that characterize CKD. Patients may develop symptoms like fatigue, edema, and hypertension as
Attorney Docket No.38215.0006P1 kidney function deteriorates. Understanding these mechanisms is crucial for clinicians, who often monitor kidney function closely when using potentially nephrotoxic drugs and consider dose adjustments or alternative treatments to minimize renal damage. [000156] In one aspect, disclosed are methods of treating or preventing a kidney injury or kidney disease in a subject receiving a nephrotoxic agent, the method comprising administering to the subject an effective amount of a megalin antagonist. Examples of kidney injuries and kidney diseases include, but are not limited to, acute kidney injury (AKI) and chronic kidney disease (CKD). [000157] In one aspect, disclosed are methods of preventing a kidney injury or kidney disease in a patient undergoing treatment with a platinum-based chemotherapy agent, the method comprising administering to the patient an effective amount of cilastatin or a pharmaceutically acceptable salt thereof at the same time as the administration of the platinum-based chemotherapy agent. [000158] In one aspect, disclosed are methods of preventing a kidney injury or kidney disease in a patient undergoing treatment with a platinum-based chemotherapy agent, the method comprising administering a megalin antagonist prior to administering the platinum-based chemotherapy agent. [000159] In some aspects, the megalin antagonist is administered for a period of time such that the megalin antagonist has a plasma concentration that is the same as or higher than the plasma concentration of the toxic agent. [000160] In some aspects, a kidney injury or kidney disease in the subject is delayed, prevented, lessened, or eliminated. In some aspects, a subject that is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy can be a subject having cancer. In other aspects, a subject that is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy can be a subject having a bacterial infection. [000161] In some aspects, treating a subject with cilastatin can be a prophylactic treatment. Thus, disclosed are methods of preventing a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to the subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin
Attorney Docket No.38215.0006P1 platinum-based chemotherapy. Also disclosed are methods of preventing a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to the subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. [000162] In some aspects, the subjects are predisposed to a kidney injury or kidney disease and/or to kidney disease. Subjects that are predisposed to a kidney injury or kidney disease and/or to kidney disease can include subjects that are undergoing platinum-based chemotherapy requiring a high dose of the platinum-based neoplastic agent, subjects that are undergoing platinum-based chemotherapy requiring a prolonged treatment regimen of the platinum-based neoplastic agent, subjects that have a genetic predisposition (e.g., subjects having megalin or glutathione S-transferases gene polymorphism) to a kidney injury or kidney disease and/or to kidney disease, and combinations thereof. Subjects that are predisposed to a kidney injury or kidney disease and/or kidney disease can also include subjects that are undergoing antimicrobial therapy requiring a high dose of the antimicrobial drug, subjects that are undergoing antimicrobial therapy requiring a prolonged treatment regimen of the antimicrobial agent, subjects that have a genetic predisposition (e.g., subjects having megalin or glutathione S- transferases gene polymorphism) to a kidney injury or kidney disease and/or to kidney disease, and combinations thereof. [000163] In some aspects, a kidney injury or kidney disease in patients undergoing or having previously undergone platinum-based chemotherapy and/or antimicrobial therapy is due to a kidney injury or kidney disease of the platinum-based chemotherapy and/or antimicrobial therapy. Cisplatin-associated a kidney injury or kidney disease is usually progressive, bilateral, and irreversible. The degree of the effects are often variable and are related to the dose; that is, the higher the cumulative dose, the greater the nephrotoxic effect. [000164] Therefore, in various aspects, disclosed are methods of treating a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. In some aspects, the a kidney injury or kidney disease in the subject is delayed, prevented, lessened, or eliminated. Also disclosed are
Attorney Docket No.38215.0006P1 methods of reducing/mitigating or preventing a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy, previously underwent platinum-based chemotherapy, or is going to begin platinum-based chemotherapy. [000165] Also disclosed are methods of treating a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. In some aspects, the kidney injury or kidney disease in the subject is delayed, prevented, lessened, or eliminated. Also disclosed are methods of reducing/mitigating or preventing a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing antimicrobial therapy, previously underwent antimicrobial therapy, or is going to begin antimicrobial therapy. [000166] A kidney injury or kidney disease is defined as rapid deterioration in the kidney function due to toxic effect of medications and chemicals. There are various forms, and some nephrotoxic drugs may affect renal function in more than one way. Different mechanisms lead to a kidney injury or kidney disease, including renal tubular toxicity, inflammation, glomerular damage, crystal nephropathy, and thrombotic microangiopathy. A kidney injury or kidney disease can be monitored or measured using several known methods. For example, a kidney injury or kidney disease can be assessed using traditional markers of a kidney injury or kidney disease and renal dysfunction including blood urea and serum creatinine. Other methods include 24 hour measurement of glomerular filtration rate (GFR), dipstick urinalysis to monitor proteinuria, urinary excretion of f3,-micro-globulin, transdermal measurement of GFR, and immunofluorescence staining. Early stages of a kidney injury or kidney disease can also be assessed using more sensitive biomarkers such as kidney injury molecule-1, serum cystatin C, and neutrophil gelatinase-associated lipocalin sera levels.. In some embodiments, assessment of a kidney injury or kidney disease is determined by measuring (1) glomerular filtration rate (GFR) via a transdermal GFR measurement system or clearance of exogenous filtration markers such as
Attorney Docket No.38215.0006P1 iohexol or inulin and (2) eGFR calculated from serum creatinine and cystatin C using the 2021 CKD-EPI Creatinine-Cystatin Equation: eGFRcr-cys = 135 x min (Scr/κ, 1)α x max(Scr/κ, 1)-0.544 x min(Scys/0.8, 1)-0.323 x max(Scys/0.8, 1)-0.778 x 0.9961Age x 0.963 [if female] where Scr = standardized serum creatinine in mg/dL, κ = 0.7 (females) or 0.9 (males), α = -0.219 (female) or -0.144 (male), min(S
cr /κ, 1) is the minimum of S
cr /κ or 1.0, max(S
cr /κ, 1) is the maximum of Scr /κ or 1.0, Scys = standardized serum cystatin C in mg/L, and Age (years). [000167] In some aspects, reducing or mitigating a kidney injury or kidney disease can include, but is not limited to, preventing a decline in the eGFR to 20% in the eGFR from baseline or abovefor patients taking cilastatin. For example, preventing a decline in the eGFR to least 10, 15, 20, 25%, 30%, 35%, 40%, 45%, 50% or higher from baseline. [000168] In some aspects, the nephrotoxic agent is a platinum-based chemotherapy agent. Thus, in some aspects, a platinum-based chemotherapy is treatment using a platinum-based antineoplastic or chemotherapy agent selected from cisplatin, carboplatin, oxaliplatin, nedaplatin, triplatin tetranitrate, phenanthriplatin, picoplatin, or satraplatin. For many cancers, the platinum- based antineoplastic agent is cisplatin, carboplatin or oxaliplatin. In some aspects, the nephrotoxic agent is cisplatin. [000169] In some aspects, the nephrotoxic agent is an antimicrobial agent. Thus, in some aspects, an antimicrobial therapy is treatment using aminoglycosides such as gentamicin, kanamycin, mycifradin, neomycin, tobramycin, streptomycin, plazomycin, and amikacin, polymyxin antibiotics such as colistin and glycopeptide antibiotics such as vancomycin. For many patients, the antimicrobial agent is gentamicin, colistin or vancomycin. [000170] In some aspects, the megalin antagonist is cilastatin or a pharmaceutically acceptable salt thereof. In some further aspects, the megalin antagonist is a pharmaceutically acceptable salt of cilastatin. In even further aspects, the pharmaceutically acceptable salt of cilastatin is cilastatin sodium. [000171] In some aspects, administering cilastatin to a subject that is going to begin platinum- based chemotherapy and/or antimicrobial therapy can mean administering cilastatin at a time prior to or coincident with the administration of the platinum-based chemotherapy and/or antimicrobial therapy agent so as to ensure that the peak cilastatin blood concentration (Cmax) is
Attorney Docket No.38215.0006P1 aligned (e.g., prior to or coincident) with the peak blood concentration (Cmax) of the platinum- based chemotherapy and/or antimicrobial therapy agent. [000172] In some aspects, administering cilastatin to a subject that is going to begin platinum- based chemotherapy and/or antimicrobial therapy can mean administering cilastatin before administering a platinum-based chemotherapy agent and/or antimicrobial therapy agent, for example, at least 2, 1, or 0.5 hours before administering a platinum-based chemotherapy agent. For example, the administration of cilastatin can begin between 15 and 30 minutes before administering a platinum-based chemotherapy and/or antimicrobial therapy agent, or between 5 and 10 minutes before administering a platinum-based chemotherapy and/or antimicrobial therapy agent. [000173] In some aspects, cilastatin is administered before, during, and after each dose of platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, cilastatin is administered before, during and/or after the first dose of platinum-based chemotherapy and/or antimicrobial therapy agent . In some aspects, cilastatin is administered before, during and/or after the last dose of platinum-based chemotherapy and/or antimicrobial therapy agent. [000174] In some aspects, administering cilastatin to a subject that is undergoing platinum-based chemotherapy and/or antimicrobial therapy can mean administering cilastatin as described above and continuing the cilastatin administration for a period of time as needed to maintain a cilastatin plasma concentration in the patient that is above the minimum effective concentration of cilastatin for the period of time during which the plasma concentration of the nephrotoxic agent, typically the platinum-based antineoplastic agent and/or antimicrobial therapy agent, is at or above a clinically relevant concentration or until at least 5 half-lives of the ototoxic agent have past. In some aspects, IV dosing of cilastatin can be administered during active administration of the nephrotoxic agent to get high plasma levels to off-set high plasma levels of the nephrotoxic agent. Then, a maintenance dose of cilastatin can be administered (via subcutaneous or oral administration) to address the long bone depot effect of the nephrotoxic agent accumulating in the long bone and being released over time. In some aspects, this form of administration could be used for prophylactic use at home by patients who have had nephrotoxic agent doses in the past and/or are concerned about the long term/low dose effects upon cessation of active dosing of the nephrotoxic agent.
Attorney Docket No.38215.0006P1 [000175] In some aspects, the megalin antagonist is administered via intravenous administration, intraperitoneal administration, intramuscular administration, subcutaneous administration, or oral administration. In some further aspects, the megalin antagonist is administered via intravenous administration. [000176] In some aspects, the patient receives the megalin antagonist before the nephrotoxic agent. In some further aspects, the patient receives the megalin antagonist at the same time as the nephrotoxic agent. [000177] Disclosed are methods of treating a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin prior to administering a platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, the subject has been determined to need platinum-based chemotherapy and/or antimicrobial therapy. Disclosed are methods of treating a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin prior to a subject receiving platinum-based chemotherapy and/or antimicrobial agent. [000178] In some aspects, any combination of the administering can occur. For example, the administration can be a combination of prior to administering a platinum-based chemotherapy and/or antimicrobial therapy agent, simultaneously with administering a platinum-based chemotherapy and/or antimicrobial therapy agent, and/or after administering a platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, administering cilastatin to a subject that is undergoing platinum-based chemotherapy and/or antimicrobial therapy can mean administering cilastatin any time during the platinum-based chemotherapy and/or antimicrobial therapy. [000179] In some aspects, administration of the megalin antagonist, such as cilastatin, is continued for a period of time to provide effective blockade while the plasma concentration of the nephrotoxic agent is in circulation. For example, cisplatin can be found (i.e., deposited) in long bones and can be slowly released; it may be too low for quantification/identification via current methods but it may be present at extremely low levels in blood and can therefore potentially be slowly accumulating in cochlea. Thus, because exposure to cisplatin can be long term, the administration of cilastatin can be long term. [000180] Typically, administering cilastatin is not a single administration but includes the complete dosing regimen of cilastatin required to treat a kidney injury or kidney disease. For
Attorney Docket No.38215.0006P1 example, a dosing regimen can include administering cilastatin before treatment with a platinum- based chemotherapy and/or antimicrobial therapy agent, during treatment with a platinum-based chemotherapy and/or antimicrobial therapy agent and/or after treatment with a platinum-based chemotherapy and/or antimicrobial therapy agent. [000181] In some aspects, cilastatin is administered to the subject intravenously, subcutaneously, intraperitoneally, intramuscularly, orally, or a combination thereof. Intravenous administration of cilastatin can occur over a short period of time (e.g., bolus injection), over a longer period of time, or continuously. In some aspects, an initial loading dose of cilastatin is administered intravenously and subsequent maintenance doses are administered intravenously, subcutaneously, intraperitoneally, intramuscularly, orally, or a combination thereof. [000182] In some aspects, a dosing regimen can be an intravenous bolus administration of cilastatin prior to (e.g., 1-30 min before, or 5 minutes, or 15 minutes, or 30 minutes, or 45 minutes or 60 minutes before) the administration of a platinum-based chemotherapy and/or antimicrobial therapy agent followed by a subcutaneous administration of cilastatin every two hours for at least 24 hours after administration of a platinum-based chemotherapy and/or antimicrobial therapy agent. In some aspects, the subcutaneous administration of cilastatin every 2, 4, 6, 8 or 12 hours can occur for at least 24, 36, 48, 60, or 72 hours after administration of a platinum-based chemotherapy and/or antimicrobial therapy agent. [000183] In some aspects, a dosing regimen can be an intravenous bolus administration of cilastatin prior to (e.g., 1-30 min before, or 5 minutes, or 15 minutes, or 30 minutes, or 45 minutes or 60 minutes before) the administration of a platinum-based chemotherapy agent followed by a continuous intravenous administration (e.g., using a peripherally inserted central catheter (PICC) line with that is connected to an intravenous continuous infusion pump). [000184] In some aspects, the total dose of cilastatin administered to a subject is equal to or greater than the dose of nephrotoxic agent administered to the subject. For example, the ratio of the cilastatin dose to the nephrotoxic agent dose may be 1:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In some aspects, the dose of cilastatin is 500 mg or 250 mg and the dose of the nephrotoxic agent (e.g., cisplatin) is about 75 mg/m
2 (e.g., about 127.5 mg or about 150 mg). [000185] In some aspects, the total dose of cilastatin administered to a subject within a 24 hour period is 200, 300, 400, or 500 mg/day to 800, 1000, 1200, 1500, 1800, or 2000 mg/day. In some aspects, the dose of cilastatin is the amount need to maintain a therapeutically effective
Attorney Docket No.38215.0006P1 amount of cilastatin present in the blood for at least 18, 24, 30, 36, 42, 48, 60, or 72 hours after administration of a platinum-based chemotherapy. [000186] In some aspects, the dose of cilastatin administered intravenously or subcutaneously to adult subjects is 500 mg, 450 mg, 400 mg, 350 mg, 300 mg, 250 mg, 200 mg, 150 mg, 100 mg or 50 mg every 6 hours or 1000 mg, 900 mg, 800 mg, 700 mg, 600 mg, 500 mg, 400 mg, 300 mg, 200 mg, or 100 mg every 4, 6, 8 or 12 hours with a maximum dose of 2000 mg/day. In some aspects, the dose of cilastatin administered intravenously or subcutaneously to adolescents, children, and infants is 0.5 to 25 mg/kg/dose, 1 to 20 mg/kg/dose, 1 to 15 mg/kg/dose, 1 to 10 mg/kg/dose every 4, 6, 8 or 10 hours with a maximum dose of 2000 g/day. [000187] In some aspects of any of the disclosed methods, cilastatin and a nephrotoxic agent are administered at the same time. In some aspects, at the same time can mean formulated together and therefore administered as one composition together. In some aspects, at the same time can mean administering within at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, or 30 minutes of each other and either the cilastatin or the platinum-based chemotherapy and/or antimicrobial therapy agent. [000188] In some aspects, cilastatin is administered by a route different from the platinum-based chemotherapy and/or antimicrobial therapy agent. For example, if the platinum-based chemotherapy and/or antimicrobial therapy agent is administered parenterally (e.g., intratumorally, intraperitoneally, intramuscularly, or intravenously), the cilastatin can be administered subcutaneously. [000189] In some aspects, a dosing regimen of the invention can include administration of cilastatin for no more than 5, 6, 7, 8, 9, or 10 consecutive days, or for no more than 5, 10, 15, or 20 days in a 30 day period. In some aspects, the dosing regimen can reduce or minimize negative effects of a long-term blockade of megalin. [000190] Disclosed are methods of enhancing the effectiveness of platinum-based chemotherapy and/or antimicrobial therapy in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy and/or antimicrobial therapy, previously underwent platinum-based chemotherapy and/or antimicrobial therapy, or is going to begin platinum-based chemotherapy and/or antimicrobial therapy. Enhancement of platinum-based chemotherapy and/or antimicrobial therapy can mean increasing the dose of platinum-based
Attorney Docket No.38215.0006P1 chemotherapy, extending the duration of platinum-based chemotherapy and/or antimicrobial therapy, improving the efficacy of platinum-based chemotherapy and/or antimicrobial therapy, or a combination thereof. Such enhancement is achieved because the reduction in a kidney injury or kidney disease associated with the administration of cilastatin permits increases in the dose and/or number of cycles of the platinum-based chemotherapy and/or antimicrobial therapy. [000191] Platinum-based chemotherapy typically includes 1 or more cycles, e.g., between 1 and 10 cycles of platinum-based chemotherapy for the subject. The dose of platinum-based chemotherapy depends on the platinum-based antineoplastic agent. For example, cisplatin has been approved for administration to subjects with metastatic testicular tumors at a dose of 20 mg/ m
2 intravenously daily for 5 days per cycle. Also, cisplatin has been approved for administration to subjects with metastatic ovarian tumors at a dose of 75 mg/m
2 to 100 mg/m
2 intravenously per cycle once every 3 to 4 weeks. Cisplatin has been approved for administration to subjects with advanced bladder cancer at a dose of 50 mg/m
2 to 70 mg/m
2 intravenously per cycle once every 3 to 4 weeks. Typically, the dose of cisplatin does not exceed 100 mg/m
2 intravenously per cycle. Oxaliplatin has been approved for administration to subjects with colorectal cancer at a dose of 85 mg/m
2, 75 mg/m
2, or 65 mg/m
2 intravenously every 2 weeks for 12 cycles. Carboplatin has been approved for administration to subjects with advanced ovarian carcinoma at a dose of 360 mg/m
2 on day 1 every 4 weeks for 6 cycles. [000192] In some aspects, the methods of treating a kidney injury or kidney disease in a subject comprising administering a therapeutically effective amount of cilastatin or a pharmaceutically acceptable salt thereof to a subject, wherein the subject is undergoing platinum-based chemotherapy and/or antimicrobial therapy, previously underwent platinum-based chemotherapy and/or antimicrobial therapy, or is going to begin platinum-based chemotherapy and/or antimicrobial therapy, which provides for an increase in the concentration or dose of platinum- based chemotherapy and/or antimicrobial therapy of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or more compared to platinum-based chemotherapy and/or antimicrobial therapy in the absence of cilastatin administration. For example, the methods can comprise titrating up the dose of the platinum-based chemotherapy and/or antimicrobial therapy if no signs of dose-limiting toxicity are observed for the platinum-based chemotherapy and/or antimicrobial therapy. In the case of cisplatin and oxaliplatin the dose can be titrated up by increments of 10
Attorney Docket No.38215.0006P1 mg/m
2 per cycle. In the case of carboplatin the dose can be titrated up by increments of 10 mg/m
2 to 30 mg/m
2 per cycle. [000193] In some aspects, the method further comprises administering an effective amount of the nephrotoxic agent to the patient. In some aspects, the nephrotoxic agent is administered sequentially with the megalin antagonist. In some aspects, the nephrotoxic agent is administered after the megalin antagonist. In some aspects, the nephrotoxic agent is administered before the megalin antagonist. In some aspects, the nephrotoxic agent is administered simultaneously with the megalin antagonist. In some aspects, the nephrotoxic agent and the megalin antagonist are co-formulated. In some aspects, the nephrotoxic agent and the megalin antagonist are not co- formulated. [000194] In some aspects, the nephrotoxic agent is administered no more than about 15 minutes before or after, about 30 minutes before or after, about 45 minutes before or after, or about 60 minutes before or after the megalin antagonist. In some aspects, the nephrotoxic agent is administered no more than about 15 minutes before or after the megalin antagonist. [000195] In some aspects, the megalin antagonist is administered to the patient at a dose ratio that is greater than 1:1, or greater than 2:1, compared to the nephrotoxic agent. [000196] In some aspects, the effective amount of megalin antagonist is from about 250 mg per day to about 2500 mg per day. Thus, in some aspects, the effective amount of megalin antagonist is from about 250 mg per day to about 2000 mg per day, from about 250 mg per day to about 1500 mg per day, from about 250 mg per day to about 1000 mg per day, from about 250 mg per day to about 500 mg per day, from about 500 mg per day to about 2500 mg per day, from about 1000 mg per day to about 2500 mg per day, from about 1500 mg per day to about 2500 mg per day, from about 2000 mg per day to about 2500 mg per day, from about 500 mg per day to about 2000 mg per day, or from about 1000 mg per day to about 1500 mg per day. [000197] In some aspects, cilastatin is administered to the patient via continuous intravenous infusion for a time-period of from about 1 hour to about 72 hours. Thus, in some aspects, cilastatin is administered to the patient via continuous intravenous infusion for a time period of from about 1 hour to about 72 hours, from about 1 hour to about 60 hours, from about 1 hour to about 48 hours, from about 1 hour to about 36 hours, or from about 1 hour to about 24 hours. In some aspects, cilastatin is administered to the patient via continuous intravenous infusion for a time-period of from about 1 hour to about 24 hours.
Attorney Docket No.38215.0006P1 [000198] In some aspects, the platinum-based chemotherapy and the megalin antagonist are co- formulated. In some aspects, the platinum-based chemotherapy agent and the megalin antagonist are not co-formulated. [000199] In some aspects, the ratio of cilastatin to platinum-based chemotherapy agent is 2:1 or greater. Thus, in some aspects, the ratio of cilastatin to platinum-based chemotherapy agent is 2:1 or greater, 2.5:1 or greater, 3:1 or greater, 3.5:1 or greater, 4:1 or greater, 4.5:1 or greater, or 5:1 or greater. [000200] In some aspects, the megalin antagonist is administered to the patient at least 1 to 60 minutes prior to administration of the platinum-based chemotherapy agent. Thus, in some aspects, the megalin antagonist is administered to the patient at least 1 to 45 minutes prior, at least 1 to 30 minutes prior, at least 1 to 15 minutes prior, at least 15 to 60 minutes prior, at least 30 to 60 minutes prior, at least 45 to 60 minutes prior, or at least 15 to 45 minutes prior to administration of the platinum-based chemotherapy agent. [000201] In some aspects, the megalin antagonist is administered to the patient prior to administering the platinum-based chemotherapy agent to the patient and at a time when a peak plasma concentration of the megalin antagonist in the patient coincides with a peak plasma concentration of the platinum-based chemotherapy agent in the patient. [000202] In some aspects, the administration of the megalin antagonist to the patient comprises administering a loading dose of the megalin antagonist to the patient via intravenous infusion followed by administering a maintenance dose of the megalin antagonist to the patient. In some aspects, the loading dose of the megalin antagonist is between 0.1 mg/kg/h and 100 mg/kg, 0.1 mg/kg/h and 80 mg/kg, 0.1 mg/kg/h and 60 mg/kg, or 0.1 mg/kg/h and 50 mg/kg. In some aspects, the maintenance dose of the megalin antagonist is administered to the patient at a repeated frequency sufficient to sustain a plasma concentration at least equivalent to a minimum effective plasma concentration. In some aspects, the maintenance dose of the megalin antagonist is between 0.1 mg/kg/h and 100 mg/kg/h. Thus, in some aspects, the maintenance dose of the megalin antagonist is between 0.1 mg/kg/h and 75 mg/kg/h, between 0.1 mg/kg/h and 50 mg/kg/h, between 0.1 mg/kg/h and 25 mg/kg/h, between 0.1 mg/kg/h and 10 mg/kg/h, between 0.1 mg/kg/h and 1 mg/kg/h, between 1 mg/kg/h and 100 mg/kg/h, between 10 mg/kg/h and 100 mg/kg/h, between 25 mg/kg/h and 100 mg/kg/h, between 50 mg/kg/h and 100 mg/kg/h, between
Attorney Docket No.38215.0006P1 75 mg/kg/h and 100 mg/kg/h, between 1 mg/kg/h and 75 mg/kg/h, or between 10 mg/kg/h and 50 mg/kg/h. [000203] In some aspects, the maintenance dose is administered via continuous intravenous infusion, subcutaneous injection, intraperitoneal injection, intramuscular injection, or orally. D. PHARMACEUTICAL COMPOSITIONS [000204] In one aspect, disclosed are compositions comprising cilastatin or a pharmaceutically acceptable salt thereof. Also disclosed are compositions comprising cilastatin together with one or more platinum-based chemotherapy agents such as, for example, cisplatin, carboplatin, oxaliplatin, nedaplatin, triplatin tetranitrate, phenanthriplatin, picoplatin, and satraplatin. Also disclosed are compositions comprising cilastatin together with cisplatin. [000205] Cilastatin inhibits the human enzyme dehydropeptidase-I (DHP-I) and is approved in a 1:1 combination with the antibiotic imipenem to extend the half-life of imipenem, which is degraded by DHP-1 (Keynan 1995). Cilastatin is also an inhibitor of the organic anion transporter 3 (OAT3) in the basolateral membrane of proximal tubular epithelial tubule endothelial cells (PTECs) (Takeda 2001). This application summarizes recent work showing that cilastatin is also an antagonist of megalin, a large glycoprotein member of the low-density lipoprotein (LDL) receptor family and a major endocytic receptor. Cilastatin has been shown to block toxicity of other agents in which cell entry is mediated by megalin. [000206] The structure of cilastatin is shown below.
[000207] Cilastatin is approved in the US as part of the fixed dose combination products PRIMAXIN
® (imipenem and cilastatin sodium) for Injection, for intravenous use (PRIMAXIN 2022) and RECARBRIO
® (imipenem/cilastatin/relebactam) for injection (RECARBRIO 2022). PRIMAXIN has been approved for use in the United States since 1985 and has more than 37
Attorney Docket No.38215.0006P1 years of documented safety and efficacy and will be the reference listed drug (RLD) for this Investigational New Drug (IND) application. However, cilastatin is not available a single agent. [000208] In some aspects, the disclosed compositions are pharmaceutical compositions comprising cilastatin in combination with a pharmaceutically acceptable carrier. By “pharmaceutically acceptable carrier” is meant a material or carrier that would be selected to minimize any degradation of the active ingredient and to minimize any adverse side effects in the subject, as would be well known to one of skill in the art. Examples of carriers include, but are not limited to, dimyristoylphosphatidyl (DMPC), phosphate buffered saline, and a multivesicular liposome. For example, PG:PC:Cholesterol:peptide or PC:peptide can be used as carriers in this invention. Other suitable pharmaceutically acceptable carriers and their formulations are described in Remington: The Science and Practice of Pharmacy (19th ed.) ed. A.R. Gennaro, Mack Publishing Company, Easton, PA 1995. Typically, an appropriate amount of pharmaceutically acceptable salt is used in the formulation to render the formulation isotonic. Other examples of the pharmaceutically acceptable carrier include, but are not limited to, saline, Ringer’s solution and dextrose solution. The pH of the solution can be from about 5 to about 8, or from about 7 to about 7.5. Further carriers include sustained release preparations such as semi-permeable matrices of solid hydrophobic polymers containing the composition, which matrices are in the form of shaped articles, e.g., films, stents (which are implanted in vessels during an angioplasty procedure), liposomes or microparticles. It will be apparent to those persons skilled in the art that certain carriers may be more preferable depending upon, for instance, the route of administration and concentration of composition being administered. These most typically would be standard carriers for administration of drugs to humans, including solutions such as sterile water, saline, and buffered solutions at physiological pH. [000209] The pharmaceutical compositions can also include thickeners, diluents, buffers, preservatives and the like, as long as the intended activity of the polypeptide, peptide, or conjugate of the invention is not compromised. The pharmaceutical compositions may also include one or more active ingredients (in addition to the composition of the invention) such as antimicrobial agents, anti-inflammatory agents, anesthetics, and the like. [000210] The pharmaceutical compositions as disclosed herein can be prepared for oral or parenteral administration.
Attorney Docket No.38215.0006P1 [000211] Pharmaceutical compositions prepared for parenteral administration include those prepared for intravenous (or intra-arterial), intramuscular, subcutaneous, intraperitoneal, transmucosal (e.g., intranasal, intravaginal, or rectal), or transdermal (e.g., topical) administration. Aerosol inhalation can also be used to deliver the fusion proteins. Thus, compositions can be prepared for parenteral administration that includes fusion proteins dissolved or suspended in an acceptable carrier, including but not limited to an aqueous carrier, such as water, buffered water, saline, buffered saline (e.g., PBS), and the like. One or more of the excipients included can help approximate physiological conditions, such as pH adjusting and buffering agents, tonicity adjusting agents, wetting agents, detergents, and the like. Where the compositions include a solid component (as they may for oral administration), one or more of the excipients can act as a binder or filler (e.g., for the formulation of a tablet, a capsule, and the like). Where the compositions are formulated for application to the skin or to a mucosal surface, one or more of the excipients can be a solvent or emulsifier for the formulation of a cream, an ointment, and the like. [000212] Preparations of parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, and emulsions. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate. Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media. Parenteral vehicles include sodium chloride solution, Ringer’s dextrose, dextrose and sodium chloride, lactated Ringer’s, or fixed oils. Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers (such as those based on Ringer’s dextrose), and the like. Preservatives and other additives may also be present such as, for example, antimicrobials, anti-oxidants, chelating agents, and inert gases and the like. [000213] The pharmaceutical compositions can be sterile and sterilized by conventional sterilization techniques or sterile filtered. Aqueous solutions can be packaged for use as is, or lyophilized, the lyophilized preparation, which is encompassed by the present disclosure, can be combined with a sterile aqueous carrier prior to administration. The pH of the pharmaceutical compositions typically will be between 3 and 11 (e.g., between about 5 and 9) or between 6 and 8 (e.g., between about 7 and 8). The resulting compositions in solid form can be packaged in multiple single dose units, each containing a fixed amount of the above-mentioned agent or agents, such as in a sealed package of tablets or capsules. The composition in solid form can
Attorney Docket No.38215.0006P1 also be packaged in a container for a flexible quantity, such as in a squeezable tube designed for a topically applicable cream or ointment. [000214] Compositions for oral administration include powders or granules, suspensions or solutions in water or non-aqueous media, capsules, sachets, or tablets. Thickeners, flavorings, diluents, emulsifiers, dispersing aids, or binders may be desirable. [000215] The pharmaceutical compositions described above can be formulated to include a therapeutically effective amount of a composition disclosed herein. In some aspects, therapeutic administration encompasses prophylactic applications. Based on genetic testing and other prognostic methods, a physician in consultation with their patient can choose a prophylactic administration where the patient has a clinically determined predisposition or increased susceptibility (in some cases, a greatly increased susceptibility) to nephrotoxicity. [000216] The pharmaceutical compositions described herein can be administered to the subject (e.g., a human subject or human patient) in an amount sufficient to delay, reduce, or preferably prevent the onset of nephrotoxicity. Accordingly, in some aspects, the subject is a human subject. In therapeutic applications, compositions are administered to a subject (e.g., a human subject) already with or diagnosed with hearing impairment in an amount sufficient to at least partially improve a sign or symptom or to inhibit the progression of (and preferably arrest) the symptoms of the condition, its complications, and consequences. An amount adequate to accomplish this is defined as a “therapeutically effective amount.” A therapeutically effective amount of a pharmaceutical composition can be an amount that achieves a cure, but that outcome is only one among several that can be achieved. As noted, a therapeutically effective amount includes amounts that provide a treatment in which the onset or progression of the nephrotoxicity is delayed, hindered, or prevented, or the nephrotoxicity is ameliorated. One or more of the symptoms can be less severe. Recovery can be accelerated in an individual who has been treated. [000217] The total therapeutically effective amount of the cilastatin in the pharmaceutical compositions disclosed herein can be administered to a mammal as a single dose, either as a bolus or by infusion over a relatively short period of time, or can be administered using a fractionated treatment protocol in which multiple doses are administered over a more prolonged period of time (e.g., a dose every 1-4, 4-6, 6-12, 12-16, or 16-24 hours, or every 2-4 days, 1-2 weeks, or once a month). Alternatively, continuous intravenous infusions sufficient to maintain
Attorney Docket No.38215.0006P1 therapeutically effective concentrations in the blood are also within the scope of the present disclosure. [000218] The pharmaceutical composition may be administered in a number of ways depending on whether local or systemic treatment is desired, and on the area to be treated. [000219] The following examples are included to illustrate the invention, but the invention should not be understood to be limited to these exemplified embodiments. E. EXAMPLES [000220] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compositions and/or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. [000221] The Examples are provided herein to illustrate the invention, and should not be construed as limiting the invention in any way. 1. PHARMACOKINETIC (PK) PARAMETERS OF CILASTATIN [000222] The PK of cilastatin in humans is well described from the PRIMAXIN® (imipenem/cilastatin) and RECARBRIO® (imipenem/cilastatin/relebactam) labeling and the clinical literature. [000223] Per the PRIMAXIN labeling, peak plasma levels of cilastatin following a 20-minute intravenous infusion of PRIMAXIN range from 31 to 49 mcg/mL for the 500 mg dose, and from 56 to 88 mcg/mL for the 1000 mg dose. The binding of cilastatin to human serum proteins is approximately 40%. The plasma half-life of cilastatin is approximately 1 hour. Approximately 70% of the cilastatin sodium dose is recovered in urine within 10 hours of administration of PRIMAXIN® (PRIMAXIN® 2022). [000224] A study of healthy volunteers given single and multiple doses of imipenem, cilastatin, or imipenem/cilastatin demonstrated that imipenem has no effect on the disposition of cilastatin (Rogers, et al.1985). Doses of cilastatin ranged from 12.5 to 1,000 mg. Multiple doses showed
Attorney Docket No.38215.0006P1 no evidence of accumulation or changes in kinetics. These data support the hypothesis that the safety data developed with imipenem and cilastatin administered together can be directly translated to the safety of cilastatin alone. [000225] Similar parameters were obtained in a study by Drusano et al (Drusano, et al.1984) in healthy volunteers given multiple doses of imipenem/cilastatin. Recent estimates of cilastatin PK parameters from the RECARBRIO® NDA show similar values (RECARBRIO® 2019). [000226] No accumulation of cilastatin in plasma or urine is observed in patients with normal renal function. However, in patients with renal impairment, Rogers et al. were the first to show that as the GFR decreased, the clearance for both imipenem and cilastatin also became slower because less drug was cleared by the kidneys (Rogers, et al.1985). The current prescribing information for PRIMAXIN® indicates a reduction in dosage depending on the degree of impairment (PRIMAXIN® 2022). TABLE 1. Intermittent Administration Continuous infusion e tes
[000227] Cilastatin plasma concentrations predicted from the model for patients with normal renal function given an initial 60-minute infusion of 250 mg cilastatin, followed by a 23-hour infusion at the rate of 163 mg cilastatin/hour for a total of 4000 mg, also exceeded the plasma cisplatin concentrations. PK theory indicates that cilastatin exposure is equivalent if the same total dose is administered either as this 24-hour infusion regimen or as three 60-minute infusions 3 times per day or four 60-minute infusions 4 times per day. 2. OPEN-LABEL PHARMACOKINETIC AND SAFETY STUDY OF CILASTATIN IN
Attorney Docket No.38215.0006P1 PATIENTS RECEIVING CISPLATIN CHEMOTHERAPY a. STUDY DESIGN [000228] A small open-label pharmacokinetic and safety study of cilastatin was conducted in chemotherapy-naïve adults with advanced stage non-small cell lung cancer. Patients with existing renal dysfunction (eGFR<60 mL/min/1.73m2 were excluded). The study design and patient flow are shown in FIG.6 (I/C = imipenem/cilastatin sodium known as Tienam outside of the United States, CDDP = cisplatin, IV = intravenous). [000229] Briefly, patients received immunotherapy (PD-1 inhibitor) and chemotherapy (pemetrexed) prior to I/C infusion. Patients also received prophylactic hydration therapy and anti-nausea medications. Patients received 100 mL of saline containing I/C for infusion (500 mg/500 mg) (0 g, 0.5 g, or 1.0 g) intravenously infused over 30 minutes. Cisplatin (75/m
2) was administered IV over 1 hour. After completion of treatment, patients also received 20 mg of furosemide IV and 1000 mL of fluid over the subsequent 2 hours. [000230] Platinum concentrations were assessed in blood and urine. Blood samples for platinum measurement were taken 30 minutes, 1 hour, 1 hour 30 minutes, 2 hours, 6 hours, 24 hours, 2 days, and 5 days after the end of cisplatin administration. In addition, urine was collected prior to, and the end of the infusion, 3 hours after cisplatin administration, and on Days 2, 5, 8, 12 and 16. [000231] Groups were conducted sequentially, beginning with 3 subjects allocated to the Control group (0 g). The next 3 were allocated to the 0.5 g group. The next 3 patients were then allocated to the 1.0 g group after confirming that there were no more than 2 renal function-related adverse events (CTCAE version 5.0 grade 3 or higher) in the 0.5 g group. All 9 participants completed the study. [000232] The median age was 65 (range, 47–70) years and eight (89%) patients were men. The stages were unresectable stage III in 1 patient, stage IVA in 4 patients, and stage IVB in 4 patients. b. PHARMACOKINETICS OF CISPLATIN IN COMBINATION WITH CILASTATIN
Attorney Docket No.38215.0006P1 [000233] The primary endpoint of the study was the pharmacokinetics of cisplatin in combination with cilastatin. Pharmacokinetic parameters are shown in Table below. Administration of cilastatin along with cisplatin slightly decreased the t
½ and AUC of serum platinum concentration, especially in the high-dose (1.0 g) I/C group. TABLE 2. I/C D
ose N C max (μg/mL） T max (h） t ½ (h) AUC (μg/mL h) [000
, p p rt of cisplatin metabolites by megalin from the apical (tubule lumen) side (as indicated by the arrows in FIG.7). This reuptake of glomerular-filtered cisplatin metabolites results in a delayed elevation or bimodal curve of platinum serum concentration. Serum platinum concentrations over time from patients in the study are shown in FIG.7. The delayed elevation peak is indicated by the arrows. Notably, the delayed elevation of platinum concentrations is observed in all three subjects in the control group (0 mg I/C), in 1 subject in the 0.5 mg I/C group, and in no subjects in the 1.0 g I/C group. The initial C
max was not affected. [000235] The administration of I/C was associated with a decrease in the secondary “delayed elevation” peak of serum cisplatin concentrations, indicating that cilastatin is likely decreasing the reuptake of glomerular-filtered cisplatin. c. RENAL FUNCTION ENDPOINTS [000236] This study also evaluated renal function. The secondary endpoint was the change in the estimated glomerular filtration rate at 8 days post treatment, as shown in Table 3. Serum creatinine and eGFR levels to 16 days after treatment is shown in FIG.8 and FIG.9, respectively. [000237] Urinary N-acetyl-β-D-glucosaminidase (NAG) is an early marker for kidney injury. This study measured the NAG/creatinine (Cr) ratio in urine (FIG.10).
Attorney Docket No.38215.0006P1 [000238] No subjects showed any clinically significant effect on renal function. The lack of a decline in renal function in the control group may be attributed to the small size of the study, and a lack of CKD in patients at baseline. TABLE 3. I/C Cr (Baseline） ⊿Cr eGFR (Baseline） ⊿eGFR 0 085 ± 009 002 ± 012 712 ± 78 −17 ± 108 6 3
3. MODEL OF CILASTATIN PK IN HUMANS [000239] To describe the pharmacokinetics of extended administration of cilastatin, a model of cilastatin pharmacokinetics in humans was developed using pooled data provided in a publication by Norrby et al (Norrby, et al.1984). These pooled data were analyzed (naïve pooled data population pharmacokinetic approach) for the two-compartment model used by Norrby et al., and parameter values were calculated for the SAAM II computer program (SAAM II Program 1994- 1998 University of Washington, Seattle, WA). As shown in FIG.11A and FIG.11B, an excellent fit to the data was obtained. [000240] The parameter results included an elimination clearance (CLE) of 179 ml/min, a central compartment volume of 8.36 L, a total distribution volume (VT) of 14.2 L, and an elimination half-life of 51 minutes. As expected, these results are similar to those obtained by Norrby et al., and they were used in the simulations of cilastatin pharmacokinetics in patients with normal renal function. These estimates are also similar to those that Gibson et al. (Gibson, et al.1985) obtained for cilastatin in subjects with normal renal function with a similar two-compartment model: elimination half-life of 51.6 min, CLE=2.648 ml/min/kg or 185 ml/min (excluding the egregious value of 6.16 ml/min/kg reported for subject 108), and VT=14 L/kg, the latter two values calculated for a 70 kg subject. [000241] Gibson et al. also studied subjects with varying levels of renal impairment. For subjects with mild renal impairment (CrCl 30-100 ml/min/1.73 m
2), these investigators found that cilastatin CLE averaged 1.41 ml/min/kg, or 98.7 ml/min for a 70 kg subject (Gibson, et al.1985). This value of CLE was used in our simulation of plasma concentrations resulting from the
Attorney Docket No.38215.0006P1 intravenous infusion of cilastatin in patients with Stage 2 impairment in renal function (eGFR 60-89 mL/min/1.73m
2). [000242] Infusion regimen simulations were carried out, with FIG.12 showing the pharmacokinetic model as diagramed by the SAAM program. Plasma concentrations resulting from a 1 hour infusion of 127.0 mg cisplatin starting simultaneously with the cilastatin infusion, were estimated using the two-compartment model and final population PK parameters published by Urien and Lokliec (Urien, et al.2004). [000243] Cilastatin and cisplatin predicted concentrations over time in subjects with mild renal impairment, given an initial 60-minute loading dose of 200 mg cilastatin, followed by a 23-hour infusion of 89.3 cilastatin mg/h for a total 2254 mg predicted by the model are shown in FIG. 13. The predicted concentrations over time in subjects with mild renal impairment given a total dose of 2250 mg as 360-minute infusion infusions of 750 mg every 8 hours, are shown in FIG. 14. Predicted maximum concentrations and exposures from all cilastatin regimens are shown in Table 4 below. TABLE 4. Intermittent Administration Continuous infusion e tes
4. RANDOMIZED, PLACEBO-CONTROLLED CLINICAL STUDY TO EVALUATE THE SAFETY, EFFICACY, AND PHARMACOKINETICS OF CILASTATIN COMPARED TO PLACEBO IN PATIENTS RECEIVING CISPLATIN [000244] The primary objective of this study is to evaluate the safety and tolerability of cilastatin in patients receiving cisplatin. Endpoints include: (1) the frequency of treatment-emergent
Attorney Docket No.38215.0006P1 adverse events (TEAEs), serious adverse events (SAEs), and drug-related adverse events (AEs); and (2) the proportion of subjects experiencing seizures, nausea, and injection site reactions. The secondary objective of this study is to assess additional key secondary efficacy outcomes. Here, endpoints include: (1) the change in measured GFR from baseline to one week post final treatment; (2) the change in eGFR from baseline to the first day of each cycle; (3) the proportion of subjects who have cisplatin dose reduced from the dose used in Cycle 1, due to signs of nephrotoxicity or ototoxicity; and (4) the proportion of patients who discontinue use of cisplatin due to signs of nephrotoxicity or ototoxicity. [000245] The timing of the co-administered doses of cisplatin and cilastatin is critical in order to minimize platinum uptake by renal tubular cells because maximal inhibition of megalin uptake depends on the combined concentration of the two compounds. To illustrate this point, the model of cisplatin pharmacokinetics proposed by Urien and Lokliec (see Urien and Lokliec (2004) Br. J. Clin. Pharmacol.57:756-763) was used to simulate cisplatin plasma concentrations following a cisplatin dose of 127 mg infused intravenously over 1 hour. The pharmacokinetic model of cilastatin pharmacokinetics was developed from data published by Norrby et al. (see Norby et al. (1984) Antimicrob. Agents Chemother.194(26):707-714) for patients with normal renal function. However, the elimination clearance calculated from this model was scaled down to conform to the value of 1.41 ml/kg/min (98.7 ml/min for a 70 kg subject) found for cilastatin by Gibson et al. (see Gibson et al. (1985) Am. J. Med.78(suppl 6A):54-61) or patients with Stage 2 renal impairment (Cler 30=100 ml/min). This model was then used to simulate cilastatin concentrations following a loading dose of 200 mg given over 1 hour to patients with moderately impaired renal function, followed by a subsequent infusion dose at a rate of 89.3 mg/hour for 23 hours. [000246] The SAAM II computer program (see University of Washington, SAAM II Program 1994-1998. Seattle, WA) was used to carry out simulations in which the cisplatin dose and the cilastatin loading dose either were administered simultaneously or with the cisplatin dose given 30 minutes after the cilastatin loading dose. The results are shown in the following two figures. It can be seen that concurrent administration provides a sharp peak concentration at 1.0 hours, whereas delayed administration of cilastatin results in a blunted peak at 1.5 hours that is somewhat lower. The combined concentration and individual concentrations of cisplatin and cilastatin at these times are shown in Table 5 below.
Attorney Docket No.38215.0006P1 TABLE 5. Time Cisplatin Cilastatin Combined 1.0 Hours 3.968 µg/ml 14.267 µg/ml 18.235 µg/ml [
kinetics, even small differences in the combined concentration of cisplatin and cilastatin could make a significant difference in the extent to which cisplatin uptake is blocked. [000248] The pharmacokinetic (PK) profile of cilastatin and cisplatin will also be evaluated in this study population. For each agent, the following PK parameters will be calculated: (1) area under the concentration-time curve (AUC) from time 0 to the last measurable concentration (AUC
0-last); (2) AUC from time 0 extrapolated to infinity (AUC
0-∞); (3) maximum observed concentration (C
max); (4) time to maximum concentration (T
max); (5) elimination clearance (Cl
E); (6) elimination rate constant (λz) and half-life (t½); and (7) volume of distribution (Vd). Additional PK parameter estimates will be calculated if deemed necessary. [000249] Additional exploratory efficacy outcomes may also be assessed. These include: (1) the proportion of patients showing Acute Kidney Disease (AKD), defined as an increase of 1.5x the serum creatinine from baseline to Day 1 of the second cycle; (2) if a subject’s renal function changes from baseline (assessed by pre-dose labs on Day 1), their dose of cilastatin will be adjusted as appropriate per the dose administration strata; (3) subjects whose renal function decreases to < 60 mL/min and are, therefore, discontinued from study drug administration; (4) the proportion of patients showing a decrease in auditory function from baseline to end of study (EOS); (5) change in hearing thresholds from baseline to EOS; and (6) the preliminary antitumor activity of cisplatin regiments in combination with cilastatin as characterized by median progression-free survival (PFS) and overall survival (OS) per response evaluation criteria. d. RATIONALE FOR THE STUDY DESIGN [000250] The target population for this study consists of chemotherapy-naïve non-small cell lung cancer (NSCLC) patients. Lung cancer (including small cell and non-small cell) is the second most common cancer in both men and women in the United States. The incidence is estimated to
Attorney Docket No.38215.0006P1 be approximately 234,580 new cases of lung cancer per year in the US, including approximately 125,070 deaths (American Cancer Society 2024). [000251] Treatment guidelines for NSCLC recommend cisplatin as part of first-line neoadjuvant and adjuvant chemotherapy, along with other agents depending on stage and subtype (NCCN 2022). The recommended cisplatin dose is 75 mg/m
2 cisplatin for 4 cycles, but may range from 50 to 100 mg/m
2. [000252] This population of patients was also chosen because cilastatin (using the approved combination of imipenem/cilastatin sodium) has been shown to be safe in a clinical study of chemotherapy-naive adults with advanced stage NSCLC. Nonclinical models have also shown that cilastatin does not compromise the anticancer activity of cisplatin against human lung cancer cells in vitro and in vivo. e. RATIONALE FOR THE DOSE SELECTION AND DOSE REGIMEN [000253] The goal of cilastatin therapy is to protect against nephrotoxicity by achieving megalin blockade during the period when the plasma concentration of cisplatin is high. [000254] The PK of cisplatin is complex. It is eliminated primarily (>90%) in urine. While the initial plasma half-life is 30 minutes, long-lived cisplatin-albumin complexes circulate and are slowly eliminated with a minimum half-life of five days or more (CISPLATIN 2019, Urien, et al. 2004). Notably, imipenem/cilastatin is not listed among the specific agents having drug-drug- interactions with cisplatin (CISPLATIN 2019, Cisplatin Monograph 2019, Gold, et al.2022). [000255] For adult patients with normal renal function (creatinine clearance greater than or equal to 90 mL/min), the maximum recommended dosage of PRIMAXIN is 1000 mg every 6 hours (PRIMAXIN 2022). This corresponds to a maximum daily dose of 4000 mg of cilastatin in patients with no renal impairment (creatinine clearance of greater than or equal to 90 mL/min). [000256] In patients with creatinine clearance of 60-89 mL/min, the maximum dose per day is 2250 mg (750 mg every 8 hours). The prescribing information of PRIMAXIN recommends infusions ranging from 20 to 60 minutes depending on dose, and notes that in patients who develop nausea during the infusion, the rate of infusion may be slowed (PRIMAXIN 2022). [000257] The clinical study detailed herein will test total doses of cilastatin approved per the PRIMAXIN label (Table 6). The first cohort will test dose regimens of cilastatin approved for subjects with no renal impairment receiving cilastatin in four 60-minute infusions every 6 hours
Attorney Docket No.38215.0006P1 and those with mild renal impairment receiving cilastatin in three 60-minute infusions every 8 hours. TABLE 6. C
ohort Stratified by e
CrCl Total Dose Regimen e
r er [
p p p g cisplatin nephrotoxicity, subjects in Cohort 2, including subjects with no renal impairment and those with mild renal impairment, will be administered cilastatin as a loading dose followed by a continuous infusion over 24 hours. These regimens contain the same total dose for each patient sub population per the approved PRIMAXIN labeling. [000259] According to basic pharmacokinetic principles, the maximum concentration of cilastatin in plasma (Cmax) will be lower for the continuous 24-hour infusion versus administration of the same dose by intermittent administration. Further, the AUC for cilastatin will be similar, regardless of the duration of the infusion, in this population. f. STUDY DESIGN [000260] This is a randomized, placebo-controlled clinical study to determine the safety, efficacy, and pharmacokinetics of cilastatin in subjects undergoing cisplatin-based chemotherapy. Briefly, cilastatin will be administered immediately prior to the first chemotherapy cycle, for 4 to 6 cycles. Two dose regimens will be tested sequentially in 2 cohorts, each in parallel with a volume-matched placebo. The dose, frequency, and duration of study drug administration will vary by cohort and by the subject’s renal function as measured by eCrCl (assessed per local standard). Cohort 1 will evaluate multiple intermittent infusions, and Cohort 2 will evaluate a
Attorney Docket No.38215.0006P1 loading dose followed by a continuous infusion over 24 hours. The total dose for each stratum will be the same in both cohorts. [000261] The treatment groups are shown in Table 7 below. TABLE 7. Stratified by Cohort N eCrCl Total D
ose Regimen [00
] su jec s w prov e n orme consen an un ergo screen ng e ore s u y participation. After a screening period of up to 21 days, but before treatment assignment, subjects will undergo measured GFR testing and audiology testing to acquire baseline values. [000263] Before treatment assignment, subjects will be stratified based on estimated creatinine clearance (eCrCL) (assessed per local standard). Each cohort (N=24) will contain approximately 12 subjects with eCrCl <90 to ≥60 mL/min, and approximately 12 subjects with eCrCl of ≥90mL/min. Qualified subjects will be randomized in a 2:1 ratio to receive cilastatin: placebo within each cohort. [000264] On Day 1 of each chemotherapy cycle, subjects who meet the eligibility criteria will begin administration of the study drug at a hospital or study center with the capacity for an overnight stay. Subjects will begin administration of the study drug as an IV infusion immediately prior to the administration of cisplatin chemotherapy. Subjects in Cohort 1 with eCrCl≥90 mL/min will receive four 60-minute infusions over 24 hours, and subjects with eCrCl <90 to ≥60 mL/min will receive three 60-minute infusions over 24 hours. In Cohort 2, subjects in both strata will receive a 24-hour infusion at the total dose determined by their eCrCl, administered as loading dose over 60 minutes followed by continuous infusion at a lower rate for 23 hours.
Attorney Docket No.38215.0006P1 [000265] Blood samples to assess the PK of cilastatin and cisplatin will be collected before study drug administration and at multiple time points through Day 2, during the first cycle only. Subjects should receive standard antiemetic medication, per National Comprehensive Cancer Network (NCCN) guidelines (NCCN 2022). Subjects will remain at the hospital/care center overnight and will be discharged on Day 2 after all infusions and assessments are complete. In subsequent cycles, if a subject’s renal function changes from baseline (assessed by pre-dose labs on Day 1), their dose will be adjusted as appropriate per the dose administration strata. Subjects whose renal function decreases to < 60 mL/min will be discontinued from study drug administration, and followed for safety assessments through EOS, if possible. [000266] During the study, subjects will be evaluated for signs of adverse events, PK, efficacy, and audiology. Approximately 14 days after the last dose, subjects will receive a phone call to evaluate safety, and 30 days after the last dose, subjects will return to the clinic for a safety evaluation visit. Approximately 90 days after the last dose, subjects will return for a safety evaluation visit and to assess final measured GFR and audiology. g. STUDY POPULATION [000267] Each subject must meet all of the following criteria to be enrolled, randomized, and treated in this study: (1) Age greater than 18 years; (2) Diagnosed with non-small cell lung cancer; (3) Considered eligible to receive a dose of at least 75mg/m
2 cisplatin over less than 24 hours on Day 1 of the first cycle, and at least the same dose is planned for at least 4 cycles; (4) eGFR greater than or equal to 60 mL/min; (5) not pregnant or nursing; (5) Evidence of post- menopausal status or negative urinary or serum pregnancy test for subjects of child-bearing potential. Subjects will be considered post-menopausal if they have been amenorrheic for 12 months without an alternative medical cause; (6) Subjects with reproductive potential must use an approved contraceptive method during and for 3 months after the study. (7) Subject is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up; (8) Be willing and able to sign the informed consent form (ICF) prior to study participation. [000268] A subject who meets any of the following criteria will be excluded from the study: (1) Patients receiving a cisplatin regimen that is administered over more than 24 hours per cycle; (2) Patients with a planned chemotherapy regimen greater than 6 cycles; (3) Serious concomitant
Attorney Docket No.38215.0006P1 disorders that would compromise the safety of patient or compromise the patient's ability to tolerate therapy; (4) Patients with cirrhosis as defined by Childs-Pugh score of C; (5) Patients with congestive heart failure with NYHA grade 4; (6) Major surgery other than biopsy within the past 4 weeks; (7) Serious concomitant infection; (8) Uncontrolled significant arrhythmia; (9) History of seizure disorder; (10) Patients with End-Stage Renal Disease (ESRD); (11) Receiving aminoglycoside antibiotics, colistin, amphotericin B, ganciclovir, or valproic acid/divalproex sodium within 4 weeks. h. TREATMENTS [000269] Treatment Assignment. Doses of cilastatin will be tested sequentially in 2 cohorts. Cohort 1 will evaluate multiple intermittent infusions, and Cohort 2 will evaluate loading dose followed by a continuous infusion over 24 hours. Each cohort will enroll 18 subjects. Among the 24 subjects targeted for each cohort, 12 subjects with a baseline eCrCl ≥ 90 and 12 subjects with a baseline eCrCl between 90 and 60 (i.e., baseline eCrCl < 90 and ≥ 60) will be enrolled. Within each cohort, subjects will be randomly assigned to receive cilastatin or placebo in a 2:1 ratio within a baseline eCrCl stratum. It is desired that treatment assignment be also as balanced as possible with respect to the cisplatin dose (≥ 100 mg/m2 or < 100 mg/m2). i. STUDY ASSESSMENTS AND PROCEDURES [000270] FIG.15A shows a Schedule of Events summarizing the clinical procedures to be performed at each time point. Individual clinical procedures are described in detail below. Additional evaluations/testing may be deemed necessary for reasons related to subject safety. [000271] Any nonscheduled procedures required for urgent evaluation of safety concerns take precedence over all routine scheduled procedures. [000272] Investigational Product, Dose, and Mode of Administration. Cilastatin will contain
mg in a 20 mL glass vile). Cilastatin will be administered by IV infusion, with the dose, frequency, and duration of infusion determined by Cohort and renal function status as shown in Table 8. TABLE 8.
Attorney Docket No.38215.0006P1 eCrCl ≥ 90, administer 1000 mg every 6 hours, 60-minute infusion r d
py, , . p g will be administered at Day 1 for 3-6 cycles, by National Comprehensive Cancer Network (NCCN) guidelines for the specific cancer type. [000274] Duration of Treatment. The duration of treatment is 4-6 cycles. The total duration of study participation for each subject (from Screening through the Day 90 follow-up visit after the last cycle) may range from approximately 194 to 216 days. [000275] Efficacy Evaluation. The start of study drug administration will be considered as Time 0 for all efficacy time points. Efficacy assessments include: (1) measured glomerular filtration rate (GFR) via a transdermal GFR measurement system or clearance of exogenous filtration markers such as iohexol or inulin; (2) eGFR calculated from serum creatinine and cystatin C using the 2021 CKD-EPI Creatinine-Cystatin Equation: eGFRcr-cys = 135 x min (Scr/κ, 1)α x max(Scr/κ, 1)-0.544 x min(Scys/0.8, 1)-0.323 x max(Scys/0.8, 1)-0.778 x 0.9961Age x 0.963 [if female] where S
cr = standardized serum creatinine in mg/dL, κ = 0.7 (females) or 0.9 (males), α = -0.219 (female) or -0.144 (male), min(Scr /κ, 1) is the minimum of Scr /κ or 1.0, max(Scr /κ, 1) is the maximum of Scr /κ or 1.0, Scys = standardized serum cystatin C in mg/L, and Age (years); (3) audiology tests; and (4) antitumor activity (survival, progression-free survival).
Attorney Docket No.38215.0006P1 [000276] Safety Evaluation. The start of study drug administration will be considered as Time 0 for all safety time points. Safety assessments include: (1) AEs; (2) Clinical safety laboratory tests (hematology, serum chemistry, and urinalysis); (3) Physical examinations; and (4) Vital signs (resting heart rate, blood pressure, respiration rate, oxygen saturation (SpO2), and body temperature. j. PHARMACOKINETIC (PK) ASSESSMENTS [000277] Blood samples for the determination of cilastatin concentration will be collected in blood collection tubes at scheduled time points as delineated in the Schedule of Events (see FIG. 15A and FIG.15B), if possible. [000278] Serum Pharmacokinetic Parameters. PK parameters for serum cilastatin will be calculated as shown in Table 9 below, as appropriate: TABLE 9. AUC0-t: The AUC from time 0 to the last observed non-zero t d
Attorney Docket No.38215.0006P1 K
el: Apparent first-order terminal elimination rate constant calculated
[000279] PK parameters will be calculated following each dose separately and combined (especially AUC
0-inf and C
max for the doses combined), as appropriate. No value for Kel, AUC0-inf, CL, Vz, or t½ will be reported for cases that do not exhibit a terminal log-linear phase in the concentration -time profile. No PK parameters will be calculated for subjects with 2 or fewer consecutive time points with detectable concentrations. Additional PK parameter estimates will be calculated if deemed necessary. k. STATISTICAL METHODS [000280] As a general rule, placebo patients in the same baseline renal function stratum (eCrCl ≥ 90 or between 60 and 90) in Cohort 1 and Cohort 2 will be combined (regardless of the cisplatin
Attorney Docket No.38215.0006P1 dose) and used as a pooled placebo to compare with patients receiving cilastatin in the same baseline renal function stratum. [000281] Change from baseline in measured GFR and eGFR will be analyzed using analysis of variance with baseline renal function (≥ 90 or between 60 and 90) and cisplatin dose (≥ 100 mg/m
2 or < 100 mg/m
2) as covariates. Proportions of subjects with specific outcomes will be summarized by treatment group and baseline eCrCl strata. Because of the small sample size, analysis will focus on providing descriptive statistics instead of testing hypotheses. Individual and mean plasma concentration-vs-time profiles will be included in the report. Descriptive statistics for plasma concentrations and PK parameter estimates will be calculated. Safety results will be summarized by treatment group for the safety analysis population. [000282] With 12 patients in each cilastatin dosing schedule and baseline renal function subgroup, the study will have >70% chance to observe at least one occurrence of a TEAE associated with cilastatin that occurs with a frequency of ≥20%. If patients receiving different administration schedules of cilastatin but with the same total dose are combined (a total of 24 patients), the study will have >70% chance to observe at least one occurrence of a TEAE associated with cilastatin that occurs with a frequency of ≥10%. The calculations assume a binomial distribution for event occurrences. [000283] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the method and compositions described herein. Such equivalents are intended to be encompassed by the following claims.
, p p rt of cisplatin metabolites by megalin from the apical (tubule lumen) side (as indicated by the arrows in FIG.7). This reuptake of glomerular-filtered cisplatin metabolites results in a delayed elevation or bimodal curve of platinum serum concentration. Serum platinum concentrations over time from patients in the study are shown in FIG.7. The delayed elevation peak is indicated by the arrows. Notably, the delayed elevation of platinum concentrations is observed in all three subjects in the control group (0 mg I/C), in 1 subject in the 0.5 mg I/C group, and in no subjects in the 1.0 g I/C group. The initial Cmax was not affected. [000235] The administration of I/C was associated with a decrease in the secondary “delayed elevation” peak of serum cisplatin concentrations, indicating that cilastatin is likely decreasing the reuptake of glomerular-filtered cisplatin. c. RENAL FUNCTION ENDPOINTS [000236] This study also evaluated renal function. The secondary endpoint was the change in the estimated glomerular filtration rate at 8 days post treatment, as shown in Table 3. Serum creatinine and eGFR levels to 16 days after treatment is shown in FIG.8 and FIG.9, respectively. [000237] Urinary N-acetyl-β-D-glucosaminidase (NAG) is an early marker for kidney injury. This study measured the NAG/creatinine (Cr) ratio in urine (FIG.10).
Attorney Docket No.38215.0006P1 [000238] No subjects showed any clinically significant effect on renal function. The lack of a decline in renal function in the control group may be attributed to the small size of the study, and a lack of CKD in patients at baseline. TABLE 3. I/C Cr (Baseline） ⊿Cr eGFR (Baseline） ⊿eGFR 0 085 ± 009 002 ± 012 712 ± 78 −17 ± 108 6 3
[000279] PK parameters will be calculated following each dose separately and combined (especially AUC0-inf and Cmax for the doses combined), as appropriate. No value for Kel, AUC0-inf, CL, Vz, or t½ will be reported for cases that do not exhibit a terminal log-linear phase in the concentration -time profile. No PK parameters will be calculated for subjects with 2 or fewer consecutive time points with detectable concentrations. Additional PK parameter estimates will be calculated if deemed necessary. k. STATISTICAL METHODS [000280] As a general rule, placebo patients in the same baseline renal function stratum (eCrCl ≥ 90 or between 60 and 90) in Cohort 1 and Cohort 2 will be combined (regardless of the cisplatin
Attorney Docket No.38215.0006P1 dose) and used as a pooled placebo to compare with patients receiving cilastatin in the same baseline renal function stratum. [000281] Change from baseline in measured GFR and eGFR will be analyzed using analysis of variance with baseline renal function (≥ 90 or between 60 and 90) and cisplatin dose (≥ 100 mg/m2 or < 100 mg/m2) as covariates. Proportions of subjects with specific outcomes will be summarized by treatment group and baseline eCrCl strata. Because of the small sample size, analysis will focus on providing descriptive statistics instead of testing hypotheses. Individual and mean plasma concentration-vs-time profiles will be included in the report. Descriptive statistics for plasma concentrations and PK parameter estimates will be calculated. Safety results will be summarized by treatment group for the safety analysis population. [000282] With 12 patients in each cilastatin dosing schedule and baseline renal function subgroup, the study will have >70% chance to observe at least one occurrence of a TEAE associated with cilastatin that occurs with a frequency of ≥20%. If patients receiving different administration schedules of cilastatin but with the same total dose are combined (a total of 24 patients), the study will have >70% chance to observe at least one occurrence of a TEAE associated with cilastatin that occurs with a frequency of ≥10%. The calculations assume a binomial distribution for event occurrences. [000283] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the method and compositions described herein. Such equivalents are intended to be encompassed by the following claims.