Treatment Field of the Invention The invention relates to imatinib for new treatment uses. Background of the Invention Acute Respiratory Distress Syndrome (ARDS) is a life-threatening respiratory condition where the lungs cannot provide the body's vital organs with enough oxygen. ARDS happens when the lungs become severely inflamed from an infection or injury. The inflammation causes fluid from nearby blood vessels to leak into the tiny air sacs in your lungs, making breathing increasingly difficult. ARDS is a heterogeneous condition resulting from a number of causes including pneumonia (of bacterial, fungal or viral origin -- including COVID-19), sepsis, trauma (for example of the head or chest), aspiration, blood transfusion, pancreatitis, ischemia-reperfusion injury, drug overdose, esophagectomy, drowning or burns. ARDS affects over 400,000 patients in the US and Europe per annum. Around 30-40% of the affected patients succumb to the condition and the ones who survive face long- term physical and neuro-psychological conditions effecting their quality of life. The disease has no approved pharmacotherapy and the patient has to rely on prolonged, unreliable and costly ventilatory treatment to manage the symptoms. Among those that survive, there is substantial long-term morbidity from deficient respiratory function, mental health problems such as post-traumatic stress and depression, kidney dysfunction that may require dialysis and substantial loss of ability to work long after the patient has been discharged from hospital. Currently, management of ARDS is merely supportive and pharmaceutical development in the field has been frustrated by many late-stage failures: the patient is given intravenous fluids and oxygen supplementation via invasive or non-invasive ventilation, while the underlying cause is treated. In many cases, ARDS patients are placed in an artificial coma and intubated in the Intensive Care Unit (ICU) for an average period of around two weeks. Imatinib is an approved chemotherapy drug for the treatment of cancer. It has the systemic name 4-[(4-methylpiperazin-1-yl)methyl]-N-(4-methyl-3-{[4-(pyridin-3- yl)pyrimidin-2-yl]amino}phenyl)benzamide and the structure:
apy for ARDS that targets the endothelial barrier dysfunction and targets the extravascular lung water (EVLWi), that is responsible for pulmonary oedema, loss of breath, multiple organ failure and ultimately death. EP2717883 discloses the use of inhibitors of ARG (abl related gene or abl-2 kinase) kinase (such as imatinib) in the treatment of inflammatory oedema, of which ARDS is an example. A Phase II trial (CounterCOVID) published in 2021 explored the hypothesis that imatinib has significant potential to the need for oxygen suppletion amongst hospitalised COVID-19 patients. Despite failing the primary endpoint, the trial did show imatinib was able to significantly protect hospitalised patients with COVID-19 from death, reduce their ICU stay and duration of invasive ventilation (Aman et al, Lancet Resp Med. 2021, 9, 957-968). There is a clear unmet need for treatments of ARDS. The present invention seeks to contribute to solving this problem. Summary of the Invention As shown by the data in the Examples section, it has been surprisingly found in clinical trials that blood albumin levels have an impact on the treatment of ARDS with imatinib. With low blood albumin levels, surprisingly, patients respond far more positively to treatment with imitanib than those with high levels. Thus, a first aspect of the present invention is imatinib or a pharmaceutically acceptable salt thereof, for use in the treatment of Acute Respiratory Distress Syndrome (ARDS), wherein the subject of treatment has a blood albumin level of less than 35 g/L. A second aspect of the invention provides a use of imatinib or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for use in the treatment of Acute Respiratory Distress Syndrome (ARDS), wherein the subject of treatment has a blood albumin level of less than 35 g/L.
A third aspect of the invention provides a method of treating ARDS comprising administering a patient with imatinib or a pharmaceutically acceptable salt thereof wherein the subject of treatment has a blood albumin level of less than 35 g/L. A fourth aspect of the invention provides a method of determining treatment of a patient with ARDS, comprising measuring the blood albumin level of the patient. Detailed Description of the Invention By the term “treatment” or “treating” as used herein, we refer to therapeutic (curative) treatment including amelioration. Treatment also includes stopping the disease from developing or slowing further progression of the disease. For example, treatment may include preventing symptoms from worsening. “Amelioration” is an improvement, or perceived improvement, in the patient’s condition, or a change in a patient’s condition that makes it, or side-effects, increasingly tolerable. ARDS is typically diagnosed according to the Berlin criteria (Table 1 below). Suitably in the present invention, the ARDS is mild, moderate or severe ARDS preferably according to the Berlin criteria, preferably moderate or severe ARDS. Table 1 Berlin criteria for diagnosis of ARDS (adapted from Rubenfeld et al. Incidence and outcomes of acute lung injury N Engl J Med 2005, 353, 1685–93) Timing Within 1 week of a known clinical insult or ne / orsenin res irator s m toms . ) r

Albumin is a type of protein made in the liver. It is one of the most abundant proteins in human blood. It is well known in the art how to perform a simple and common serum albumin blood test in order to measure a patient’s blood albumin levels (see for instance Chapter 3 in Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition Walker HK, Hall WD, Hurst JW, editors, 1990). In the instance of the present invention, a “low blood albumin level” is considered to be less than 35 g/L. Relative to some of the other biomarkers considered either to classify ARDS, or prognose its treatment, albumin is significantly easier and quicker to measure, providing another benefit to the invention; time is of the essence in an emergency care setting. However, before the present invention, there was no knowledge that ARDS patients could be better treated with imatinib by reference to their albumin levels. This finding is new and unexpected. Suitably the subject of treatment has a blood albumin level of less than 34 g/L, preferably less than 33.5 g/L, preferably less than 33 g/L, preferably less than 32.5 g/L, more preferably less than 32 g/L, yet more preferably 31.9 g/L, yet more preferably less than 31.5 g/L, even more preferably less than 31 g/L, such as less than 30.5 g/L, for example less than 30 g/L, and/or the subject of treatment has a blood albumin level of more than 20 g/L, preferably more than 22 g/L, more preferably more than 24 g/L, even more preferably more than 26 g/L. ARDS is often present in patients with other ailments. Thus, in one embodiment the subject of treatment has, or is suspected of having, pneumonia of bacterial, fungal or viral origin, a viral infection, sepsis, trauma (for example head or chest trauma), aspiration, blood transfusion, pancreatitis, ischemia-reperfusion injury, drug overdose, esophagectomy, drowning, smoke inhalation, aspiration or burns. Preferably the subject of treatment has, or is suspected of having, a viral infection, preferably a coronavirus infection, for example SARS (severe acute respiratory syndrome) or SARS-CoV-2, and preferably COVID-19 or long COVID. In one embodiment, the subject to be treated is infected with, or suspected to be infected with, a coronavirus, such as Covid-19. In a further embodiment, the subject infected with, or suspected to be infected with, a coronavirus is categorised as stage 3, 4, or 5 on the WHO Ordinal Scale for Clinical Improvement. WHO Ordinal Scale for
Clinical Improvement measures illness severity over time (Michael O’Kelly & Siying Li (2020), Statistics in Biopharmaceutical Research, 12:4, 451-460). “Covid-19” refers to an infectious disease caused by the virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Mechanical ventilation is the primary supportive, invasive measure utilized in patients with acute respiratory distress syndrome. Suitably the subject of treatment has received invasive ventilation, i.e. before the subject receives treatment with imatinib. Preferably the subject of treatment has received invasive ventilation on at least 1 day within the 7 days prior to receiving imatinib, such as at least 2 days, 3 days, 4 days, 5 days, 6 days or 7 days. Suitably the subject of treatment has received invasive ventilation on the day before receiving imatinib, and/or the subject of treatment has received invasive ventilation on the same day as receiving imatinib. Suitably as imatinib treatment starts and progresses, the patient may have days receiving invasive ventilation whilst undergoing treatment with imatinib. “Patient” and “subject” are used interchangeably and refer to the subject that is to be administered the imatinib. Preferably, the subject is a human. As used herein, a pharmaceutically acceptable salt is a salt with a pharmaceutically acceptable acid or base. Pharmaceutically acceptable acids include both inorganic acids such as hydrochloric, sulphuric, phosphoric, diphosphoric, hydrobromic or nitric acid and organic acids such as citric, fumaric, maleic, malic, ascorbic, succinic, tartaric, benzoic, acetic, methanesulfonic, ethanesulfonic, salicylic, stearic, benzenesulfonic or p-toluenesulfonic acid. Pharmaceutically acceptable bases include alkali metal (e.g. sodium or potassium) and alkali earth metal (e.g. calcium or magnesium) hydroxides and organic bases such as alkyl amines, aryl amines or heterocyclic amines. The skilled practitioner would understand that the compound of the invention may be formulated as a pharmaceutical composition comprising imatinib or a pharmaceutically acceptable salt thereof. In one embodiment, imatinib is the only active agent in the composition. By only active agent it is meant that the composition does not contain other components which may be used in the treatment of ARDS. Alternatively, imatinib may be administered alongside a second active agent for treating ARDS, i.e. the composition comprising imatinib may also comprise a second active agent, or the second active agent may be administered in a separate composition. The two
compositions are administered to the subject simultaneously, separately or sequentially. In another embodiment, imatinib may be administered alongside a second active agent for treating an ailment that is not ARDS, for example the second active agent may be an active agent that treats pneumonia of bacterial, fungal or viral origin, a viral infection, sepsis, trauma (for example head or chest trauma), aspiration, blood transfusion, pancreatitis, ischemia-reperfusion injury, drug overdose, esophagectomy, drowning or burns. Preferably the second active agent treats a viral infection, preferably a coronavirus infection, for example SARS (severe acute respiratory syndrome) or SARS-CoV-2, preferably COVID-19. The two active agents may be formulated into a single composition, or administered via two separate compositions. The two compositions are administered to the subject simultaneously, separately or sequentially. Accordingly, exemplary second active agents that may be used are anti- viral drugs, such as Remdesivir, Chloroquine, Hydroxychloroquine, Azithromycin, Ivermectin, Lopinavir, Ritonavir, Molnupiravir, Nitazoxanide, baricitinib or tocilizumab, preferably remdesivir or dexamethasone. The compositions of the present invention provide for the administration of more than one drug, and they can be administered simultaneously, sequentially or separately. It is not necessary that they are packed together (but this is one embodiment of the invention). It is also not necessary that they are administered at the same time. As used herein, “separate” administration means that the drugs are administered as part of the same overall dosage regimen (which could comprise a number of days), but preferably on the same day. As used herein “simultaneously” means that the drugs are to be taken together or formulated as a single composition. As used herein, “sequentially” means that the drugs are administered at about the same time, and preferably within about 1 hour of each other. The compositions comprising imatinib, or a pharmaceutically acceptable salt thereof, may contain a pharmaceutically acceptable carrier. By “pharmaceutically acceptable carrier” is meant any diluent or excipient, such as fillers or binders, that is compatible with the other ingredients of the composition, and which is not deleterious to the recipient. The pharmaceutically acceptable carrier can be selected on the basis of the desired route of administration, in accordance with standard pharmaceutical practices. In the present invention, imatinib may be administered in a variety of dosage forms. In one embodiment, imatinib may be formulated in a format suitable for oral, rectal,
parenteral, intranasal or transdermal administration or administration by inhalation or by suppository. Imatinib may be administered orally, for example as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules. Preferably, imatinib is formulated such that it is suitable for oral administration, for example tablets and capsules. Imatinib may also be administered parenterally, whether subcutaneously, intravenously, intramuscularly, intrasternally, transdermally or by infusion techniques. Imatinib may also be administered as suppositories. Imatinib may also be administered by inhalation. An advantage of inhaled medications is their direct delivery to the area of rich blood supply in comparison to many medications taken by oral route. Thus, the absorption is very rapid as the alveoli have an enormous surface area and rich blood supply and first pass metabolism is bypassed. The present invention also provides an inhalation device containing imatinib. Typically said device is a metered dose inhaler (MDI), which contains a pharmaceutically acceptable chemical propellant to push the medication out of the inhaler. Imatinib may also be administered by intranasal administration. The nasal cavity’s highly permeable tissue is very receptive to medication and absorbs it quickly and efficiently. Nasal drug delivery is less painful and invasive than injections, generating less anxiety among patients. By this method absorption is very rapid and first pass metabolism is usually bypassed, thus reducing inter-patient variability. Further, the present invention also provides an intranasal device containing imatinib. Imatinib may also be administered by sublingual administration. The present invention therefore also provides a sub-lingual tablet comprising imatinib. Imatinib may also be formulated with an agent which reduces degradation of the substance by processes other than the normal metabolism of the patient, such as anti- bacterial agents, or inhibitors of protease enzymes which might be the present in the patient or in commensural or parasite organisms living on or within the patient, and which are capable of degrading the compound. Liquid dispersions for oral administration may be syrups, emulsions and suspensions.
Suspensions and emulsions may contain as carrier, for example a natural gum, agar, sodium alginate, pectin, methylcellulose, carboxymethylcellulose, or polyvinyl alcohol. The suspension or solutions for intramuscular injections may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g. sterile water, olive oil, ethyl oleate, glycols, e.g. propylene glycol, and if desired, a suitable amount of lidocaine hydrochloride. Solutions for injection or infusion may contain as carrier, for example, sterile water or preferably they may be in the form of sterile, aqueous, isotonic saline solutions. In an embodiment of the invention, imatinib is administered in an effective amount to treat the symptoms of pneumonitis and/or myocarditis. An effective dose will be apparent to one skilled in the art and is dependent on a number of factors including age, sex, weight, which the medical practitioner will be capable of determining. In a preferred embodiment, imatinib is administered in doses of 0.5 to 400 mg, more preferably 1 to 400 mg, more preferably 2.5 to 400 mg, more preferably 5 mg to 400 mg, more preferably 100 to 500 mg, preferably 200 mg to 450 mg, preferably 300 mg to 400 mg. The lower limit for a dose is preferably 0.5 mg, 1 mg, 1.5 mg, 2 mg, 2.5 mg, 3 mg, 4 mg, 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50 mg, 55 mg, 60 mg, 65 mg, 70 mg, 75 mg, 80 mg, 85 mg, 90 mg, 95 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg or 200 mg. The upper limit for a dose is preferably 400 mg, 390 mg, 380 mg, 370 mg, 360 mg, 350 mg, 340 mg, 330, mg, 320 mg, 310 mg, 300 mg, 290 mg, 280 mg, 270 mg, 260 mg, 250 mg, 240 mg, 230 mg, 220 mg or 210 mg. Any of the aforementioned lower or upper limits of the ranges may be combined with each other and are herein disclosed. In some embodiments, the dose is 300 mg to 400 mg. In some embodiments, the dose is 400 mg. Any of the above doses may be administered once a day or twice a day, preferably twice a day. In an embodiment of the invention, imatinib is administered at least once a day. Preferably it is administered as a single daily dose. Preferably the single daily dose is of 200 mg to 450 mg, preferably 300 mg to 400 mg. Preferably it is 400 mg. It will be appreciated that a lower dose may be needed in a paediatric patient.
In an embodiment of the invention, imatinib is administered twice daily. Preferably each dose is 200 mg to 450 mg, preferably 300 mg to 400 mg. Preferably it is 400 mg. Preferably, the dosage regime is such that the total daily dosage of imatinib does not exceed 800 mg, more preferably 400 mg. The present invention also relates to use of imatinib, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for use in the treatment of ARDS, wherein the subject of treatment has a blood albumin level of less than 35 g/L. This embodiment of the invention may have any of the preferred features described above. In one embodiment, the subject of treatment is or is suspected to having a viral infection, such as a coronavirus infection, for example Covid-19. The present invention also relates to a method of treating ARDS comprising administering the patient with Imatinib or a pharmaceutically acceptable salt thereof, wherein the patient has a blood albumin level of less than 35 g/L. This embodiment of the invention may have any of the preferred features described above. The method of administration may be according to any of the routes described above. In one aspect, the patient has a blood albumin level of less than the median level for ARDS patients. The present invention also relates to a method of determining treatment of a patient with ARDS, comprising measuring the blood albumin level of the patient. In accordance with the invention, patients are found to respond far more positively to imatinib treatment with low amounts of blood albumin levels than patients with high blood albumin levels. Therefore, the present invention allows for more accurate prognosis and decisions to be made by physicians on whether to administer a patient with imatinib. This embodiment of the invention may have any of the preferred features described above. Suitably the measured albumin level is less than 35 g/L, preferably less than 34 g/L, more preferably less than 33 g/L, more preferably less than 32 g/L, yet more preferably 31.9 g/L, even more preferably less than 31 g/L, such as less than 30 g/L and the patient is prescribed imatinib or a pharmaceutically acceptable salt thereof.
Suitably the measured albumin level is 35 g/L or more and the patient is not prescribed imatinib or a pharmaceutically acceptable salt thereof. Suitably the measured albumin level is more than 20 g/L, preferably more than 22 g/L, more preferably more than 24 g/L, even more preferably more than 26 g/L and the patient is prescribed imatinib or a pharmaceutically acceptable salt thereof. In one aspect, the measured albumin level is less than the median level for ARDS patients. Suitably the measuring of the blood albumin level of the patient is performed in vitro, using any suitable method. For the avoidance of doubt, the present invention also embraces prodrugs which react in vivo to give a compound of the present invention. The following examples illustrate the invention. Examples The CounterCOVID study as reported in Lancet Resp Med. 2021, 9, 957-968 was performed. Patients were being administered with standard of care for COVID according to the treating physician’s judgment. That included remdesivir or dexamethasone. Data on albumin levels at study inclusion and at days 1, 3, 5, 7 and 9 were analysed with respect to patient outcome amongst the subset of patients that received invasively mechanical ventilation. This subset includes the patients in the trial who can be considered to have moderate to severe ARDS according to the Berlin criteria. The albumin level used for the analysis is the one closest in time to the start of invasive mechanical ventilation. Albumin values are given in g/L. Group A is placebo group; Group B is imatinib treated with a loading dose of 800 mg at the start of the trial followed by a daily dose of 400 mg for a further 9 days (10 days total dosing). Patients were monitored for 28 days. Treatment effect is measured using the number of ventilator-free days while alive at Day 28, which is the most widely used composite outcome in the ARDS literature (VFDsurv). This composite endpoint combines
mortality with number of days after successful liberation from invasive mechanical ventilation among survivors, truncated at 28 days (Schoenfeld and Bernard, Crit Care Med 2002, 30, 1772–77). The VFD
surv value is calculated as the lesser of number of days free of invasive mechanical ventilation, or zero if the patient has died. Figures in the columns for albumin at inclusion of the patient into the trial (Alb at start) and for albumin at the start of invasive mechanical ventilation (Alb at MV start) are italicised if above the average for their respective columns. The average and standard deviations for the respective columns are shown at the bottom of the tables. An asterisk in the days of mechanical ventilation (days_MV) column indicates death Table 2 Albumin levels and ventilation outcomes from CounterCOVID study of patients with ARDS due to COVID-19 Group Alb at Alb at MV date_start date_stop days_MV VFDsurv start start mv mv
A 32 32 0 24 24 4 B 37.8 30 3 7 4 24
Study participants were then categorised as hypoalbuminemic or hyperalbuminemic with respect to various experimental analytical cut-offs in level of blood albumin at the start of mechanical ventilation from 31g/L to 35g/L. (The median level for the mechanically ventilated population of ARDS patients in the CounterCOVID trial at the time of starting mechanical ventilation was 31.9g/L, whereas the median level of this population at the time of entry into the trial was 35.0g/L.) The VFDsurv value was then analysed for each group.
Table 3: VFDsurv results for patients hypoalbuminemic to cut-offs shown in the column headings of albumin in g/L at start of mechanical ventilation. Figures in parentheses indicate numbers of patients included in the analysis. Alb at MV 31.9 32 33 34 35 start c t-

o cut-offs shown in column headings of albumin in g/L at start of mechanical ventilation. Figures in parentheses indicate numbers of patients included in the analysis. Alb at MV 31.9 32 33 34 35 start c t-

, atients are segregated into responders and non-responders by applying the cut-off of blood albumin level at above the medium value of 31.9 g/L up to 35 g/L. At these levels, the test allocates almost all of the responders into the hypoalbuminemic category and almost all of the non- responders into the hyperalbuminemic category, i.e. table 3 versus table 4 shows that for each albumin blood level, in table 3 (i.e. hypoalbuminemic) there is a great increase in VFDsurv score for patients being treated with imatinib, whereas in table 4 (i.e. hyperalbuminemic) the VFDsurv scores are similar – i.e. imatinib has had no effect on the patient. It was also found that there was no difference in the outcome based on the concomitant COVID mediation, e.g. remdesivir or dexamethasone. This demonstrates that imatinib is suited to be an ancillary drug to be used in these patients rather than an alternative drug. Statistical analysis
A statistical analysis of the VFDsurv scores for the placebo and imatinib treated groups of patients who were hypoalbuminemic relative to a value of 32 g/L at the start of invasive mechanical ventilation indicates the difference between these two datasets being significant with a p value of 0.039 according to a two-tailed t-test. Similar results were found when performed on the results for 31.9 g/L, 33 g/L, 34 g/L and 35 g/L, supporting the statistical difference for each. t-Test: Two-Sample Assuming Unequal Variances Variable Variable 1 2 Mean 8 16.07 Variance 100.62 91.61 Observations 14 14 Hypothesized Mean Difference 0 df 26 t Stat -2.18 P(T<=t) one-tail 0.019 t Critical one-tail 1.71 P(T<=t) two-tail 0.039 t Critical two-tail 2.06 Conclusion The data and analysis supports the conclusion that patients with low blood albumin level will respond far more positively to imitanib treatment of ARDS, than patients with high blood albumin level.