RU2826983C2 - Method of treating covid-19 using ox40 (cd134) receptor agonists - Google Patents

Abstract

FIELD: medicine; pharmaceutics.

SUBSTANCE: invention relates to the field of medicine and pharmaceutics, namely to the use of a drug acting on CD8+ T-lymphocytes of memory for coronavirus infections preceding infection with coronavirus SARS-CoV-2, in an individual, wherein said CD8+ T-lymphocytes are activated in said individual when infected with coronavirus SARS-CoV-2, for correction of inadequate immune response to infection with coronavirus SARS-CoV-2, in said individual or to generate an adequate immune response to said infection in said individual. Use of a drug acting on CD8+ T-lymphocytes of memory for coronavirus infections preceding infection with coronavirus SARS-CoV-2, in an individual, where said CD8+ T-lymphocytes are activated in said individual when infected with coronavirus SARS-CoV-2, to correct an inadequate immune response to infection with coronavirus SARS-CoV-2, in said individual or to generate an adequate immune response to said infection in said individual, where the effect on CD8+ T-lymphocytes of memory to coronavirus infections preceding infection with coronavirus SARS-CoV-2 in an individual, activated in said individual when infected with coronavirus SARS-CoV-2, includes one of the following: stimulating these lymphocytes and increasing their activity with respect to SARS-CoV-2 antigens; reduced level of apoptosis of these lymphocytes; reducing the level of death of these lymphocytes; inducing an increase in the activity of these lymphocytes with respect to SARS-CoV-2 antigens; increased migration of these lymphocytes to the source of antigen production, i.e. to tissues affected by SARS-CoV-2 virus; reduced ability of these lymphocytes to activate apoptosis in lymphocytes highly avid to SARS-CoV-2 virus; reduced ability of these lymphocytes to initiate death of lymphocytes highly avid to SARS-CoV-2 virus; stimulating the destruction of cells affected by the SARS-CoV-2 virus; high efficiency of eliminating the SARS-CoV-2 virus, where the inadequate immune response is the immune response, which is caused by or consists in stimulation of CD8+ T-lymphocyte proliferation in this individual to previous coronaviruses, characterized by reduced avidity to coronavirus SARS-CoV-2, high level of intrinsic apoptosis and stimulating activity on high avid CD8+ T-lymphocytes.

EFFECT: said invention enables to restore functional activity of CD8+ T-lymphocytes of memory to previous coronavirus infections, characterized by reduced avidity to antigens SARS-CoV-2, with respect to antigens of said virus, represented by cells affected by the virus, suppress the individual’s inadequate immune response during infection with SARS-CoV-2, caused by activation of proliferation of CD8+ T-lymphocytes of memory to previous coronavirus infections during infection with SARS-CoV-2 in an individual and manifested by increased apoptosis and death of such lymphocytes, as well as highly avid CD8+ T-lymphocytes, leading to development of lymphopenia, to restore generation of adequate immune response in patients with SARS-CoV-2 infection with a severe course of the infectious process, increase the effectiveness of treating the disease caused by infection with SARS-CoV-2, reduce mortality in the severe course of COVID-19.

5 cl, 2 dwg, 1 tbl, 2 ex

Description

Field of technology

The invention relates to the field of medicine and pharmaceuticals and can be used to produce drugs against the infection caused by the new coronavirus SARS-CoV-2 (COVID-19), to treat this infection, to diagnose susceptibility to a severe course of this infection and adverse reactions to vaccination to prevent this infection.

State of the art

Treatment of the disease caused by the new coronavirus SARS-CoV-2 (COVID-19) is an unsolved and extremely urgent problem of modern medicine due to the pandemic nature of the spread of the infection, significant individual variability of clinical manifestations and high mortality from this disease.

Currently, the factors that determine the severe course of the disease caused by the SARS-CoV-2 coronavirus are not fully understood, which causes significant difficulties in choosing an effective strategy for the treatment and prevention of the disease caused by the SARS-CoV-2 coronavirus, including prevention with vaccines.

In many countries, active research continues to find effective strategies to treat the disease caused by the new coronavirus SARS-CoV-2.

In the United States, the antiviral drug remdesivir is officially recommended for the treatment of coronavirus infection, and glucocorticoids and anticoagulants are recommended as non-specific treatments.

Remdesivir and glucocorticoids are relatively effective and do not solve the entire spectrum of problems in the treatment of the disease caused by the SARS-CoV-2 coronavirus.

Other antiviral and immunomodulatory drugs proposed for the treatment of the new coronavirus infection are recommended for use in clinical trials. Their effectiveness and safety for the treatment of the disease caused by the SARS-CoV-2 coronavirus have not been confirmed.

Thus, clinical efficacy in the treatment of coronavirus infection caused by the SARS-CoV-2 coronavirus has been proven for very few drugs, and society urgently needs to expand the arsenal of clinically effective drugs and strategies for the treatment of this disease.

The OX40 receptor (OX40) (also known as CD134, TNFRSF4, ACT-4, ACT35, and TXGP1L) is a member of the TNF receptor superfamily. OX40 is found to be expressed on activated T cells. High numbers of OX40+ T cells have been detected in cancer patients in tumors (tumor-infiltrating lymphocytes) and in draining lymph nodes (Weinberg, A. et al. J. Immunol. 164: 2160-69, 2000; Petty, J. et al. Am. J. Surg. 183: 512-518, 2002). In mouse tumor models, it has been shown that OX40 engagement in vivo during tumor priming significantly delayed and prevented tumor initiation. Therefore, one strategy proposed is to enhance the mammalian immune response to an antigen during immunization or cancer treatment by engaging the OX40 receptor with molecules that regulate its activity (WO 99/42585, 26.08.1999; Weinberg et al., 2000).

One of the OX40 receptor agonists, the monoclonal antibody PF-04518600, is being tested as an additional drug in the treatment of cancer in a number of ongoing clinical trials.

The possibility of engaging the OX40 receptor signaling pathway and modulating its activity for the treatment of the disease caused by the SARS-CoV-2 coronavirus, especially in severe cases of this disease, has not been proposed or investigated in the prior art.

Thus, the proposed invention is aimed at solving the problem of expanding the arsenal of effective drugs and strategies for the treatment of the disease caused by the SARS-CoV-2 coronavirus, especially in severe cases of this disease.

Disclosure of the essence of the invention

Unexpectedly, the authors of the present invention discovered that in the case of a severe course of COVID-19, CD8+ T lymphocytes of memory to previous coronavirus infections are activated faster than CD8+ T lymphocytes specific to this virus begin to be produced. Having reduced avidity, CD8+ T lymphocytes of memory to previous coronavirus infections trigger the process of their own apoptosis and apoptosis of the specific CD8+ T lymphocytes being produced, which leads to the formation of lymphopenia and an insufficient immune response to the virus and, as a result, to a severe course of the disease caused by infection with the SARS-CoV-2 coronavirus.

Therefore, according to the first aspect of the present invention, there is provided the use of at least one antigen specific for the SARS-CoV-2 coronavirus for diagnosing susceptibility to a severe course of a disease caused by infection with the SARS-CoV-2 coronavirus, as well as a method for diagnosing susceptibility to a severe course of a disease caused by infection with the SARS-CoV-2 coronavirus, wherein said method and said use preferably comprise contacting non-activated CD8+ T lymphocytes of a patient with at least one antigen specific for the SARS-CoV-2 coronavirus, quantifying the cytolytic CD8+ T lymphocytes of the patient specific for coronaviruses other than the SARS-CoV-2 coronavirus and the cytolytic CD8+ T lymphocytes of the patient specific for the SARS-CoV-2 coronavirus, comparing the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than the SARS-CoV-2 coronavirus and the number of cytolytic CD8+ T lymphocytes specific for the SARS-CoV-2 coronavirus, and receiving a diagnosis of susceptibility to a severe course of the disease caused by infection with the SARS-CoV-2 coronavirus, when the number of cytolytic CD8+ T-lymphocytes of the patient specific for coronaviruses other than the SARS-CoV-2 coronavirus exceeds the number of cytolytic CD8+ T-lymphocytes of the patient specific for the SARS-CoV-2 coronavirus.

In this embodiment of the present invention, the patient is a mammal, preferably a human, who has been diagnosed with a SARS-CoV-2 coronavirus infection.

Also according to the present invention, there is provided the use of at least one antigen specific for the SARS-CoV-2 coronavirus for diagnosing a predisposition to an adverse reaction to vaccination for the prevention of a disease caused by infection with the SARS-CoV-2 coronavirus, as well as a method for diagnosing a predisposition to an adverse reaction to vaccination for the prevention of a disease caused by infection with the SARS-CoV-2 coronavirus, wherein said method and said use preferably include contacting non-activated CD8+ T lymphocytes of a patient with at least one antigen specific for the SARS-CoV-2 coronavirus, quantifying the patient's cytolytic CD8+ T lymphocytes specific for coronaviruses other than the SARS-CoV-2 coronavirus and the patient's cytolytic CD8+ T lymphocytes specific for the SARS-CoV-2 coronavirus, comparing the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than the SARS-CoV-2 coronavirus and the number of cytolytic CD8+ SARS-CoV-2-specific T lymphocytes and detection of a predisposition to an adverse reaction to vaccination for the prevention of disease caused by SARS-CoV-2 coronavirus infection when the patient's non-SARS-CoV-2-specific cytolytic CD8+ T lymphocyte count exceeds the patient's SARS-CoV-2-specific cytolytic CD8+ T lymphocyte count.

In this embodiment of the present invention, the patient is a mammal, preferably a human, who needs to be vaccinated to prevent a disease caused by infection with the SARS-CoV-2 coronavirus.

More preferably, the person in question is not infected with the SARS-CoV-2 coronavirus.

Unexpectedly, the authors of the present invention discovered that the predisposition to a severe course of the disease caused by infection with the SARS-CoV-2 coronavirus can not only be diagnosed by CD8+ T lymphocytes of memory to previous coronavirus infections, but also prevented by influencing these lymphocytes.

Thus, when influencing the OX40 CD8+ receptor signaling pathway, memory T lymphocytes to previous coronavirus infections, when infected with the SARS-CoV-2 coronavirus, can be stimulated, and an increase in their activity against SARS-CoV-2 antigens can be induced with a decrease in the level of their apoptosis and death. This effect also allows for an increase in the expression of interferon-gamma characteristic of an active specific immune response and an increase in the migration of lymphocytes to the source of antigen production, i.e. to cells affected by the SARS-CoV-2 virus.

Such an effect can be realized, for example, with the help of at least one OX40 receptor agonist, preferably selected from a monoclonal or polyclonal antibody which is an OX40 receptor agonist, for example, the antibody PF-04518600 (PF-8600), an antigen-binding fragment of such an antibody, a natural or artificial OX40 receptor ligand - OX40L.

The OX40 receptor agonist of the present invention may be administered either alone or in combination with other agents for the treatment of severe disease caused by infection with the SARS-CoV-2 coronavirus, which may optionally be other OX40 receptor agonists or have other biological activity useful for the treatment of said disease.

Preferably, according to the present invention, the antibody PF-8600 can be co-administered with utomilumab (PF-05082566).

Thus, in the second aspect of the present invention, there is provided a method of influencing CD8+ T lymphocytes memory to coronavirus infections preceding infection with coronavirus SARS-CoV-2 in an individual, activated in said individual upon infection with coronavirus SARS-CoV-2, and the use of this method for alleviating, treating or preventing severe disease caused by infection with coronavirus SARS-CoV-2 in this individual.

In this case, the effect on CD8+ T lymphocytes of memory to coronavirus infections preceding the infection with the SARS-CoV-2 coronavirus, activated in the said individual upon infection with the SARS-CoV-2 coronavirus, hereinafter means at least one of the following:

- stimulation of these lymphocytes and increasing their activity in relation to SARS-CoV-2 antigens;

- a decrease in the level of apoptosis of these lymphocytes;

- reduction of the death rate of these lymphocytes;

- induction of increased activity of these lymphocytes in relation to SARS-CoV-2 antigens;

- increased migration of these lymphocytes to the source of antigen production, i.e. to tissues affected by the SARS-CoV-2 virus;

- a decrease in the ability of these lymphocytes to activate apoptosis in lymphocytes with high avidity for the SARS-CoV-2 virus;

- a decrease in the ability of these lymphocytes to initiate the death of lymphocytes that are highly avid to the SARS-CoV-2 virus;

- stimulation of the destruction of cells affected by the SARS-CoV-2 virus;

- increasing the efficiency of elimination of the SARS-CoV-2 virus.

The said method consists of administering to an individual a medicinal product that affects CD8+ T lymphocytes memory to coronavirus infections that preceded the infection with the SARS-CoV-2 coronavirus in the individual, activated in the said individual upon infection with the SARS-CoV-2 coronavirus, in a therapeutically effective amount.

At least one OX40 receptor agonist can be used as a medicinal product that affects CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, preferably selected from a monoclonal or polyclonal antibody that is an OX40 receptor agonist, for example, the PF-04518600 antibody (PF-8600), an antigen-binding fragment of such an antibody, a natural or artificial OX40 receptor ligand - OX40L.

The said medicinal product may be presented in the form of a pharmaceutical composition, a dosage form containing such a composition, including a dosage form for administration of a single dose.

The OX40 receptor agonist, the pharmaceutical composition or dosage form containing it, may be presented as part of a kit or a set. Moreover, said kit and set are preferably kits and sets suitable for use in medicine, i.e. manufactured taking into account the requirements for the manufacture of products and articles intended for medical use.

The kit or set according to the present invention may further comprise an instruction prescribing the use of the OX40 receptor agonist contained in the kit for influencing memory CD8+ T lymphocytes to coronavirus infections preceding the SARS-CoV-2 coronavirus infection in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, as well as for carrying out methods and applications involving such an effect, for example, for carrying out methods and applications according to the invention for the treatment, prevention or alleviation of a severe course of a disease caused by a SARS-CoV-2 coronavirus infection.

Optionally, the kit and set of the invention may comprise a device for administering an OX40 receptor agonist.

The said pharmaceutical composition, dosage form, kit or set may also optionally additionally contain another medicinal product for the treatment of a disease caused by SARS-CoV-2 coronavirus infection.

According to the present invention, there is also provided the use of a medicinal product that acts on CD8+ memory T lymphocytes to coronavirus infections preceding infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, preferably an OX40 receptor agonist selected from a monoclonal or polyclonal antibody that is an OX40 receptor agonist, for example, the PF-04518600 antibody (PF-8600), an antigen-binding fragment of such an antibody, a natural or artificial OX40 receptor ligand - OX40L, or a pharmaceutical composition containing said OX40 receptor agonist, or a dosage form containing said OX40 receptor agonist, or a kit or kit containing said OX40 receptor agonist, for at least one of the following:

- for the treatment, relief or prevention of severe disease caused by infection with the SARS-CoV-2 coronavirus in an individual;

- for the production of a medicine for the treatment, alleviation or prevention of severe disease caused by infection with the SARS-CoV-2 coronavirus in an individual;

- to correct an inadequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus;

- to generate an adequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus;

- to prevent an adverse reaction to vaccination for the prevention of disease caused by SARS-CoV-2 coronavirus infection;

- for the production of a medicine to prevent an adverse reaction to vaccination for the prevention of disease caused by SARS-CoV-2 coronavirus infection.

The present invention also relates to the use of an OX40 receptor agonist selected from a monoclonal or polyclonal antibody which is an OX40 receptor agonist, for example the antibody PF-04518600 (PF-8600), an antigen-binding fragment of such an antibody, a natural or artificial OX40 receptor ligand - OX40L, or a pharmaceutical composition containing said OX40 receptor agonist, or a dosage form containing said OX40 receptor agonist, or a kit or kit containing said OX40 receptor agonist, for at least one of the following:

- for the effect on CD8+ T lymphocytes of memory to coronavirus infections preceding infection with the SARS-CoV-2 coronavirus, activated in the said individual upon infection with the SARS-CoV-2 coronavirus, where the said effect is defined above in this document;

- for the treatment, relief or prevention of severe disease caused by infection with the SARS-CoV-2 coronavirus in an individual;

- for the production of a medicine for the treatment, alleviation or prevention of severe disease caused by infection with the SARS-CoV-2 coronavirus in an individual;

- to correct an inadequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus;

- for the production of a medicine for the correction of an inadequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus;

- to generate an adequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus;

- for the production of a drug for generating an adequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus;

- to prevent an adverse reaction to vaccination for the prevention of disease caused by infection with the SARS-CoV-2 coronavirus;

- for the production of a medicine to prevent an adverse reaction to vaccination for the prevention of disease caused by SARS-CoV-2 coronavirus infection.

The present invention also relates to a method for alleviating, treating or preventing severe disease caused by infection with the SARS-CoV-2 coronavirus.

According to the said method of the invention, an individual in need thereof is administered a medicinal product that affects CD8+ T memory lymphocytes to coronavirus infections that preceded the SARS-CoV-2 coronavirus infection in the individual, preferably an OX40 receptor agonist selected from a monoclonal or polyclonal antibody that is an OX40 receptor agonist, for example, the PF-04518600 (PF-8600) antibody, an antigen-binding fragment of such an antibody, a natural or artificial OX40 receptor ligand - OX40L, or a pharmaceutical composition containing the said OX40 receptor agonist, or a dosage form containing the said OX40 receptor agonist, or a kit or set containing the said OX40 receptor agonist, in a therapeutically effective amount.

The present invention relates to the use of a method for influencing CD8+ memory T lymphocytes to coronavirus infections preceding infection with SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with SARS-CoV-2 coronavirus, as defined above in this document, for:

- to correct an inadequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus; and/or

- to generate an adequate immune response in an individual infected with the SARS-CoV-2 coronavirus to infection with the SARS-CoV-2 coronavirus.

The said method consists in administering to an individual a medicinal product that affects CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in the individual, preferably an OX40 receptor agonist selected from a monoclonal or polyclonal antibody that is an OX40 receptor agonist, for example, the PF-04518600 (PF-8600) antibody, an antigen-binding fragment of such an antibody, a natural or artificial OX40 receptor ligand - OX40L, or a pharmaceutical composition containing the said OX40 receptor agonist, or a dosage form containing the said OX40 receptor agonist, or a kit or set containing the said OX40 receptor agonist, in a therapeutically effective amount.

The present invention ensures the achievement of the following technical results:

- restoration of the functional activity of CD8+ T lymphocytes of memory to previous coronavirus infections, characterized by reduced avidity to SARS-CoV-2 coronavirus antigens, in relation to the antigens of this virus, represented by cells affected by the virus;

- suppression of an inadequate immune response of an individual when infected with the SARS-CoV-2 coronavirus, caused by the activation of proliferation of CD8+ T lymphocytes of memory to previous coronavirus infections when infected with the SARS-CoV-2 coronavirus in an individual and manifested by increased apoptosis and death of such lymphocytes, as well as high-avidity CD8+ T lymphocytes, leading to the development of lymphopenia;

- restoration of the generation of an adequate immune response in patients infected with the SARS-CoV-2 coronavirus with a severe course of the infectious process;

- increasing the effectiveness of treatment of diseases caused by infection with the SARS-CoV-2 coronavirus;

- reduction of mortality in severe cases of COVID-19.

The present invention also makes it possible to expand the arsenal of effective means for the treatment and prevention of severe disease caused by infection with the SARS-CoV-2 coronavirus.

Brief description of the drawings

Figure 1 shows a diagram of the development of a severe course of the disease caused by infection of an individual with the SARS-CoV-2 coronavirus.

Figure 2 shows a treatment regimen for severe disease caused by infection of an individual with the SARS-CoV-2 coronavirus, which involves blocking the natural course of the disease after the stage of interaction of CD8+ memory T lymphocytes to previous coronaviruses with target cells infected with the SARS-CoV-2 virus by using OX40 receptor agonists (in particular, for example, the monoclonal antibody PF-04518600 (PF-8600) for therapeutic purposes).

Implementation of the invention

The phenomenon of antibody-dependent enhancement of infection, which manifests itself in aggravation of the disease in vaccinated individuals, has been known for a long time. The essence of this phenomenon is the reduced (insufficient) avidity of antibodies (ability to bind to the antigen) produced in response to the vaccine compared to the pool of antibodies produced during the formation of a natural adaptive immune response, and, as a consequence, not only their inability to perform a protective function, but also their stimulation of an expansion of the spectrum of cells affected by the virus, including macrophages. As a result, a more severe course of the disease is observed.

However, this phenomenon is traditionally associated with vaccine antibodies. For the T-cell component of the adaptive immune response, this phenomenon has not been described. For COVID-19, the phenomenon of antibody-dependent enhancement of infection has not been documented.

WO 99/42585 describes compositions containing an OX40 receptor binding agent for enhancing an antigen-specific immune response. In order to enhance and maintain the immune response of a mammal to a selected antigen, it is proposed to act on the memory cells of the immune system in such a way that their number increases, thereby enhancing the response of the immune system to said selected antigen.

According to WO 99/42585, it is proposed to act on memory cells using an agent that binds the OX40 receptor, which can be selected from OX40L and corresponding antibodies.

WO 99/42585 reports that interaction of the OX40 receptor with CD4+ T cells, especially, for example, during or shortly after priming of such cells with an antigen, can lead to an enhanced response of the CD4+ T cells to that antigen, which leads to an increased response to that antigen. WO 99/42585 therefore concludes that by enhancing the immune response through the use of molecules that interact with the OX40 receptor during T cell priming, the resistance of an animal to disease can be markedly increased by enhancing T cell recognition of antigens of infectious agents.

However, WO 99/42585 did not investigate the causes of the severe course of the disease caused by SARS-CoV-2 infection, as well as the possibilities of its alleviation, treatment and prevention.

It has been previously shown (see Chelsea M. Black, Todd D. Armstrong and Elizabeth M. Jaffee Cancer Immunol Res; 2(4); 307–19. 2014 AACR) that in mice, upon contact with a tumor antigen, expression of apoptotic proteins is initiated in specific CD8+ T lymphocytes characterized by reduced avidity, leading to their death and suppression of their function is observed, and apoptosis of low-avidity T lymphocytes stimulates apoptosis of high-avidity CD8+ T lymphocytes.

The same study showed that stimulation of low-avidity CD8+ T lymphocytes with a monoclonal antibody, an OX40 receptor agonist (CD134), blocks their apoptosis and induces an increase in their activity with respect to the target antigen. When an OX40 receptor agonist is administered to experimental animals, a decrease in the level of apoptosis in low-avidity CD8+ T lymphocytes and their death is observed. At the same time, an increase in the expression of interferon-gamma characteristic of an active specific immune response and an increase in the migration of these lymphocytes to the source of antigen production are observed. The death of high-avidity lymphocytes also decreases. Thus, this model demonstrates the possibility of correcting an inadequate immune response caused by the activation of low-avidity CD8+ T lymphocytes using OX40 receptor activation by its agonists.

However, this possibility was demonstrated only for tumor antigens, but not for SARS-CoV-2-specific antigens. The role of low-avidity CD8+ T lymphocytes produced in response to infection with coronaviruses other than SARS-CoV-2 in the development of severe disease in SARS-CoV-2 infection was also unknown.

Previously, a strong correlation was noted between low lymphocyte levels and the severity of the infectious process during infection with the SARS-CoV-2 virus (see Le Bert, N. et al. SARS-CoV-2-specific T cell immunity in cases of COVID-19 and SARS, and uninfected controls. Nature https://doi.org/10.1038/s41586-020-2550-z (2020).). Also, an extremely low level of peripheral blood lymphocytes was noted as a characteristic feature of the severe course of COVID-19, a phenomenon for which no explanation has yet been proposed (see Fathi N, Rezaei N. Lymphopenia in COVID-19: Therapeutic opportunities. Cell Biol Int. 2020; 1–6. https://doi.org/10.1002/cbin.11403. LETTER OPEN Lymphopenia predicts disease severity of COVID-19: a descriptive and predictive study Signal Transduction and Targeted Therapy (2020) 5:33 ; https://doi.org/10.1038/s41392-020-0148-4, Zhao Q, Meng M, Kumar R, Wu Y, Huang J, Deng Y, Weng Z, Yang L, Lymphopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: a review. A systemic review and meta-analysis, International Journal of Infectious Diseases (2020), doi: https://doi.org/10.1016/j.ijid.2020.04.086). In particular, patients with severe COVID-19 had extremely low levels of blood lymphocytes. However, no clear pathway for the formation of lymphopenia in COVID-19 patients has yet been proposed.

Unexpectedly, the present inventors have discovered that reduced avidity of antibodies produced during infection with the SARS-CoV-2 virus may cause the development of the antibody-dependent enhancement phenomenon of COVID-19 and be responsible for the severe course of the disease caused by infection with the SARS-CoV-2 virus.

Moreover, in this document, a severe course of the disease caused by SARS-CoV-2 virus infection is understood as a course of this disease, the clinical features of which meet the criteria: respiratory rate > 30; SpO2 ≤ 93%; PaO2 / FiO2 ≤ 300 mm Hg; decreased level of consciousness, agitation; changes in CT (RG) typical for viral damage (the volume of the lesion is significant or subtotal; CT 3-4); arterial blood lactate > 2 mmol / l; qSOFA > 2 points; unstable hemodynamics (systolic BP 90 mm Hg or diastolic BP 60 mm Hg, diuresis 20 ml / hour) (Temporary methodological recommendations of the Ministry of Health of the Russian Federation. Prevention, diagnosis and treatment of a new coronavirus infection. Version 7 of 03.06.2020).

In particular, the authors of the present invention obtained data indicating a rapid production of class G antibodies, ahead of the increase in IgM titer. These data are confirmed by the work of Yu H-qiong, Sun B-qing, Fang Z-fu, et al. Distinct features of SARS-CoV-2-specific IgA response in COVID-19 patients. Eur Respir J 2020; in press (https://doi.org/10.1183/13993003.01526-2020), which showed that IgA and IgG levels were higher in patients with severe courses of the disease compared to milder ones. The significance of the differences was for IgA (P<0.001) and IgG (P<0.001). In contrast to the increase in the levels of these immunoglobulins in severe cases of the disease, there were no reliable differences between the compared groups in the level of IgM.

These data, as the authors of the present invention subsequently found out, indicate that in severe cases of COVID-19, immunological memory to previous coronavirus infections plays an important role in the formation of the characteristics of the immunological response to the infection, i.e. the rapid production of class G antibodies, ahead of the increase in the IgM titer, can be explained by the immune response to previous contact of the adaptive immune system with specific antigens similar to the antigens of the SARS-CoV-2 coronavirus.

The inventors of the present invention realized that since the SARS-CoV-2 virus is new and there are no vaccines specific for coronaviruses, the only sources of antigens for activating the adaptive immune system could be other coronaviruses common in the human population (4 types are known) that have common antigenic determinants with SARS-CoV-2.

Considering that the peculiarity of these antigenic determinants is, on the one hand, the ability to induce antibody-producing immunological memory cells, and on the other hand, the insufficient avidity of these antibodies for the effective elimination of the SARS-CoV-2 virus, the authors unexpectedly determined that it is the presence of immunological memory T cells to previous coronavirus infections in COVID-19 patients that can cause the development of the phenomenon of antibody-dependent enhancement of COVID-19 and may be responsible for the severe course of the disease.

Accordingly, the present invention has been created by the inventors, which in its first aspect is useful for diagnosing the predisposition of a patient infected with the SARS-CoV-2 coronavirus to a severe course of the disease caused by said infection.

In particular, in accordance with this aspect of the invention, the use of at least one antigen specific for the SARS-CoV-2 coronavirus and the corresponding method will be particularly useful for predisposing a patient infected with the SARS-CoV-2 coronavirus to a severe course of the disease caused by said infection.

In particular, susceptibility to severe disease caused by infection with coronavirus SARS-CoV-2 can be determined by contacting non-activated CD8+ T lymphocytes of a patient with at least one antigen specific for coronavirus SARS-CoV-2, quantifying the patient's cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 and the patient's cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2, comparing the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 and the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2, and obtaining a diagnosis of susceptibility to severe disease caused by infection with coronavirus SARS-CoV-2 if the number of cytolytic CD8+ T lymphocytes specific for coronaviruses in the patient exceeds other than the SARS-CoV-2 coronavirus, the number of cytolytic CD8+ T-lymphocytes of the patient specific for the SARS-CoV-2 coronavirus.

To quantify virus-specific cytolytic CD8+ T lymphocytes in accordance with the present invention, methods for quantifying virus-specific cytolytic CD8+ T lymphocytes that are well known in the art can be used.

The comparison of the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 and the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2 can be carried out using mathematical methods well known to those skilled in the art. For example, the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 can be divided by the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2, and the division result can be compared with one. If it exceeds one, it can be concluded that the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 exceeds the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2.

In this embodiment of the present invention, the patient is a mammal, preferably a human, who has been diagnosed with a SARS-CoV-2 coronavirus infection.

The present inventors also found that the presence of immunological memory T cells to previous coronavirus infections may be responsible for an adverse reaction to vaccination to prevent disease caused by the SARS-CoV-2 coronavirus.

Accordingly, the present invention may be useful for diagnosing the predisposition of an individual to an adverse reaction to vaccination for the prevention of a disease caused by infection with the SARS-CoV-2 coronavirus.

Particularly useful for such diagnostics would be the use of at least one antigen specific to the SARS-CoV-2 coronavirus and an appropriate method.

In particular, the predisposition to an adverse reaction to vaccination for the prevention of a disease caused by infection with the coronavirus SARS-CoV-2 in accordance with the present invention can be determined by contacting unactivated CD8+ T lymphocytes of a patient with at least one antigen specific for the coronavirus SARS-CoV-2, quantifying the cytolytic CD8+ T lymphocytes of the patient specific for coronaviruses other than the coronavirus SARS-CoV-2 and the cytolytic CD8+ T lymphocytes of the patient specific for the coronavirus SARS-CoV-2, comparing the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than the coronavirus SARS-CoV-2 and the number of cytolytic CD8+ T lymphocytes specific for the coronavirus SARS-CoV-2, and detecting the predisposition of the patient to an adverse reaction to vaccination for the prevention of a disease caused by infection with the coronavirus SARS-CoV-2 when the number exceeds the patient's cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2, the number of patient's cytolytic CD8+ T lymphocytes specific for SARS-CoV-2.

An adverse reaction in accordance with the present invention is understood to be an inadequate immune response to vaccination for the prevention of a disease caused by infection with the SARS-CoV-2 coronavirus, i.e. such an immune response, which is caused by or consists of stimulating the proliferation of CD8+ T lymphocytes in this patient to previous coronaviruses, characterized by reduced avidity to the SARS-CoV-2 coronavirus, an increased level of intrinsic apoptosis and stimulating activity in relation to the apoptosis of high-avidity CD8+ T lymphocytes.

For the quantitative assessment of virus-specific cytolytic CD8+ T lymphocytes in accordance with this embodiment of the invention, methods for the quantitative determination of virus-specific cytolytic CD8+ T lymphocytes well known in the art can also be used.

According to this embodiment of the present invention, the comparison of the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 and the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2 can also be performed using mathematical methods well known to those skilled in the art. For example, the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 can be divided by the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2, and the division result can be compared with one. If one is exceeded, it can be concluded that the number of cytolytic CD8+ T lymphocytes specific for coronaviruses other than SARS-CoV-2 exceeds the number of cytolytic CD8+ T lymphocytes specific for coronavirus SARS-CoV-2.

In this embodiment of the present invention, the patient is a mammal, preferably a human, who needs vaccination to prevent a disease caused by infection with the SARS-CoV-2 coronavirus. Preferably, said human is not infected with the SARS-CoV-2 coronavirus.

The authors of the present invention unexpectedly discovered that lymphopenia in COVID-19 patients, associated with severe disease progression, is also a consequence of the existence of immunological memory T cells to previous coronavirus infections in the modern population of COVID-19 patients.

As a result, the inventors of the present invention found that, in the case of SARS-CoV-2 virus infection, especially in the case of severe disease caused by such infection, it would be beneficial to stimulate low-avidity CD8+ T lymphocytes and induce an increase in their activity against the target antigen, as well as to reduce the level of apoptosis in low-avidity CD8+ T lymphocytes and the level of their death.

The inventors have also found that this can be achieved by administering to a patient infected with SARS-CoV-2, especially if the patient has a severe course of the disease, an agent that can stimulate low-avidity CD8+ T lymphocytes and induce an increase in their activity in relation to an antigen specific for SARS-CoV-2, as well as reduce the level of apoptosis and the level of death in low-avidity CD8+ T lymphocytes.

As unexpectedly discovered by the authors of the present invention, an OX40 receptor agonist can be used as such a means, since when this agonist is administered to patients with COVID-19, low-avidity CD8+ T lymphocytes can be stimulated and an increase in their activity against SARS-CoV-2 antigens can be induced while reducing the level of apoptosis in low-avidity CD8+ T lymphocytes and the level of their death, and an increase in the expression of interferon-gamma characteristic of an active specific immune response and an increase in the migration of these low-avidity lymphocytes to the source of antigen production, i.e. the SARS-CoV-2 virus, are also ensured. Also, when an OX40 receptor agonist is administered to patients with COVID-19, the death of high-avidity lymphocytes can be reduced.

Thus, the authors of the present invention have demonstrated that in patients with COVID-19, especially in severe cases of the disease caused by infection with the SARS-CoV-2 virus, including lymphopenia, with the help of OX40 receptor agonists, it is possible to correct an inadequate immune response caused by the activation of the proliferation of low-avidity CD8+ T lymphocytes, and restore the generation of an adequate immune response in these patients. In particular, when influencing the OX40 receptor signaling pathway, CD8+ T lymphocytes with memory of previous coronavirus infections, when infected with the SARS-CoV-2 coronavirus, can be stimulated, and an increase in their activity against SARS-CoV-2 antigens can be induced with a decrease in the level of their apoptosis and their death, as well as an increase in the expression of interferon-gamma characteristic of an active specific immune response and an increase in the migration of lymphocytes to the source of antigen production, i.e. to cells affected by the SARS-CoV-2 virus.

Accordingly, the inventors of the present invention have found that OX40 receptor agonists can be used to treat, alleviate or prevent severe disease caused by SARS-CoV-2 infection and, accordingly, prevent lymphopenia in severe disease caused by SARS-CoV-2 infection by blocking the process in which CD8+ T lymphocytes of memory for previous coronavirus infections are activated faster than CD8+ T lymphocytes specific to this virus begin to be produced, trigger their own apoptosis and apoptosis of the specific CD8+ T lymphocytes being produced, leading to the formation of lymphopenia and an insufficient immune response to the SARS-CoV-2 coronavirus.

Particularly useful for alleviating, treating or preventing severe disease caused by infection with the SARS-CoV-2 coronavirus may be the implementation of a method of influencing CD8+ T lymphocytes memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in the said individual upon infection with the SARS-CoV-2 coronavirus.

The said method consists of administering to an individual a medicinal product that affects CD8+ T lymphocytes memory to coronavirus infections that preceded the infection with the SARS-CoV-2 coronavirus in the individual, activated in the said individual upon infection with the SARS-CoV-2 coronavirus, in a therapeutically effective amount.

The individual to whom, in accordance with the present invention, it is proposed to administer a medicinal product that affects CD8+ T lymphocytes of memory to coronavirus infections is hereinafter understood to be a mammal infected with the SARS-CoV-2 coronavirus.

Preferably, said mammal infected with the SARS-CoV-2 coronavirus is a human, more preferably said human has either had previous infections with a coronavirus other than the SARS-CoV-2 coronavirus, or has detected memory CD8+ T lymphocytes or antibodies to coronaviruses other than the SARS-CoV-2 coronavirus, or has been diagnosed with susceptibility to a severe course of a disease caused by the SARS-CoV-2 coronavirus, for example, in accordance with the above-described method of the invention, or has lymphopenia and/or is in a severe condition due to infection with the SARS-CoV-2 coronavirus, and/or has an inadequate immune response to infection with the SARS-CoV-2 coronavirus caused by the activation of low-avidity CD8+ T lymphocytes, wherein said inadequate immune response is understood to be an immune response that is caused by or consists of stimulating the proliferation of the individual CD8+ T lymphocytes to precursor coronaviruses, characterized by reduced avidity to the SARS-CoV-2 coronavirus, increased levels of intrinsic apoptosis, and stimulating activity against apoptosis of high-avidity CD8+ T lymphocytes.

An OX40 receptor agonist or a drug containing such an agonist is used as a medicinal product that acts on CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in the said individual upon infection with the SARS-CoV-2 coronavirus.

Accordingly, the term "a medicinal product that acts on CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus" is used in this document both in relation to at least one OX40 receptor agonist and in relation to a pharmaceutical composition comprising at least one such OX40 receptor agonist, optionally with another therapeutic agent, a dosage form comprising said composition or said OX40 receptor agonist.

Moreover, the said OX40 receptor agonist, the said composition or the said dosage form may be contained in a kit or set, which are preferably kits and sets suitable for use in medicine, i.e. kits and sets manufactured taking into account the requirements for the manufacture of products and articles intended for medical use.

A kit or a set according to the present invention may comprise at least one OX40 receptor agonist, as well as instructions for using the OX40 receptor agonist contained in the kit in a manner as discussed in detail herein, for example, to target CD8+ memory T lymphocytes to coronavirus infections preceding infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, as well as to carry out methods and uses involving such targeting, for example, to carry out methods and uses according to the invention for the alleviation, treatment or prevention of severe disease caused by infection with the SARS-CoV-2 coronavirus.

Such a kit or set may optionally additionally contain another medicinal product for the treatment of a disease caused by infection with the coronavirus SARS-CoV-2, as well as a device for administering and/or storing an OX40 receptor agonist and/or said other medicinal product for the treatment of a disease caused by infection with the coronavirus SARS-CoV-2.

In a preferred embodiment of the present invention, the OX40 receptor agonist or pharmaceutical composition containing it in the kit or set is located inside a device for storing and/or administering the OX40 receptor agonist or pharmaceutical composition containing it.

In a preferred embodiment of the present invention, such a device is a pre-filled syringe.

Any molecule that exhibits OX40 receptor agonist activity can be used as an OX40 receptor agonist. Methods for obtaining and/or screening such molecules are well known in the art.

In a preferred embodiment of the present invention, such a molecule is a monoclonal or polyclonal antibody that is an OX40 receptor agonist, a natural or artificial OX40 receptor ligand - OX40L.

Various monoclonal and polyclonal antibodies that can be used according to the present invention are disclosed, for example, in WO 99/42585, 26.08.1999; WO2009079335A1, 25.06.2009; Rationale for anti-OX40 cancer immunotherapy. Aspeslagh S, Postel-Vinay S, Rusakiewicz S, Soria JC, Zitvogel L, Marabelle A. Eur J Cancer. 2016 Jan;52:50-66. doi: 10.1016/j.ejca.2015.08.021. Epub 2015 Nov 30. PMID: 26645943 Review; OX40 is a potent immune-stimulating target in late-stage cancer patients. Curti BD, Kovacsovics-Bankowski M, Morris N, Walker E, Chisholm L, Floyd K, Walker J, Gonzalez I, Meeuwsen T, Fox BA, Moudgil T, Miller W, Haley D, Coffey T, Fisher B, Delanty-Miller L, Rymarchyk N, Kelly T, Crocenzi T, Bernstein E, Sanborn R, Urba WJ, Weinberg AD. Cancer Res. 2013 Dec 15;73(24):7189-7198. doi: 10.1158/0008-5472.CAN-12-4174. Epub 2013 Oct 31. PMID: 24177180 Free PMC article. Clinical Trial; Administration of low-dose combination anti-CTLA4, anti-CD137, and anti-OX40 into murine tumor or proximal to the tumor draining lymph node induces systemic tumor regression. Hebb JPO, Mosley AR, Vences-Catalán F, Rajasekaran N, Rosén A, Ellmark P, Felsher DW. Cancer Immunol Immunother. 2018 Jan;67(1):47-60. doi: 10.1007/s00262-017-2059-y. Epub 2017 Sep 13. PMID: 28905118 Free PMC articl; GBR 830, an anti-OX40, improves skin gene signatures and clinical scores in patients with atopic dermatitis. Guttman-Yassky E, Pavel AB, Zhou L, Estrada YD, Zhang N, Xu H, Peng X, Wen HC, Govas P, Gudi G, Ca V, Fang H, Salhi Y, Back J, Reddy V, Bissonnette R, Maari C, Grossman F, Wolff G. J Allergy Clin Immunol. 2019 Aug;144(2):482-493.e7. doi: 10.1016/j.jaci.2018.11.053. Epub 2019 Feb 6. PMID: 30738171 Free article. Clinical Trial; Ligand-Blocking and Membrane-Proximal Domain Targeting Anti-OX40 Antibodies Mediate Potent T Cell-Stimulatory and Anti-Tumor Activity. Zhang P, Tu GH, Wei J, Santiago P, Larrabee LR, Liao-Chan S, Mistry T, Chu ML, Sai T, Lindquist K, Long H, Chaparro-Riggers J, Salek-Ardakani S, Yeung YA. Cell Rep. 2019 Jun 11;27(11):3117-3123.e5. doi: 10.1016/j.celrep.2019.05.027. PMID: 31189099 Free article; PLGA-nanoparticle mediated delivery of anti-OX40 monoclonal antibody enhances anti-tumor cytotoxic T cell responses. Chen M, Ouyang H, Zhou S, Li J, Ye Y. Cell Immunol. 2014 Feb;287(2):91-9. doi: 10.1016/j.cellimm.2014.01.003. Epub 2014 Jan 13. PMID: 24487032; Depleting tumor-specific Tregs at a single site eradicates disseminated tumors. Marabelle A, Kohrt H, Sagiv-Barfi I, Ajami B, Axtell RC, Zhou G, Rajapaksa R, Green MR, Torchia J, Brody J, Luong R, Rosenblum MD, Steinman L, Levitsky HI, Tse V, Levy R. J Clin Invest. 2013 Jun;123(6):2447-63. doi:10.1172/JCI64859. PMID: 23728179 Free PMC article; Phase I randomized study of KHK4083, an anti-OX40 monoclonal antibody, in patients with mild to moderate plaque psoriasis. Papp KA, Gooderham MJ, Girard G, Raman M, Strout V. J Eur Acad Dermatol Venereol. 2017 Aug;31(8):1324-1332. doi: 10.1111/jdv.14313. Epub 2017 Jun 14. PMID: 28556418 Free PMC article. Clinical Trial; Biomarkers for immunostimulatory monoclonal antibodies in combination strategies for melanoma and other tumor types. Ascierto PA, Kalos M, Schaer DA, Callahan MK, Wolchok JD. Clin Cancer Res. 2013 Mar 1;19(5):1009-20. doi: 10.1158/1078-0432.CCR-12-2982. PMID: 23460532 Free article; OX40 expression enhances the prognostic significance of CD8 positive lymphocyte infiltration in colorectal cancer. Weixler B, Cremonesi E, Sorge R, Muraro MG, Delko T, Nebiker CA, Däster S, Governa V, Amicarella F, Soysal SD, Kettelhack C, von Holzen UW, Eppenberger-Castori S, Spagnoli GC, Oertli D, Iezzi G, Terracciano L, Tornillo L, Sconocchia G, Droeser RA. Oncotarget. 2015 Nov 10;6(35):37588-99. doi: 10.18632/oncotarget.5940. PMID: 26439988 Free PMC article.

More preferably, in accordance with the present invention, an antibody which is an OX40 receptor agonist is used as an OX40 receptor agonist.

More preferably, in accordance with the present invention, the OX40 receptor agonist is an antibody developed by Pfizer and known as the PF-04518600 or PF-8600 antibody (Abstract 1053PD: A First-in-Human (FIH) Study of PF-04518600 (PF-8600) OX40 Agonist in Adult Patients (pts) With Select Advanced Malignancies. Diab, A. 2016 European Society for Medical Oncology (ESMO) Congress. http://www.pfizer.com/files/news/esmo/Pfizer_Oncology_Data_Presentations_at_ESMO_2016.pdf. Accessed February 27, 2017; Study of OX40 Agonist PF-04518600 Alone and in Combination With 4-1BB Agonist PF-05082566. https://www.clinicaltrials.gov/ct2/show/NCT02315066?term=PF-04518600&rank=1. Accessed February 27, 2017;. Pfizer to Collaborate with the National Cancer Institute to Study Three Immunotherapy Agents Targeting Multiple Cancers. November 14, 2016. http://www.pfizer.com/news/press-release/press-release-detail/pfizer_to_collaborate_with_national_cancer_institute_to_study_three immunotherapy_agents targeting_multiple_cancers. Accessed February 27, 2017).

This antibody is at various stages of clinical trials for the treatment of cancer (02 Oct 2019 Phase-I/II clinical trials in Squamous cell cancer (Combination therapy, Late-stage disease, Metastatic disease, Second-line therapy or greater) in USA, Australia , France, Canada, Canada, Japan, Poland, Taiwan, United Kingdom (IV) (NCT02554812), 17 Jul 2019 Phase-II clinical trials in Breast cancer (Combination therapy, Second-line therapy or greater, Inoperable/Unresectable, Recurrent) in USA (IV) (NCT03971409), 06 Jun 2019 Array BioPharma in collaboration with Pfizer plans a phase II trial for Breast cancer (Combination therapy, Metastatic disease, Inoperable/Unresectable) in USA (IV) (NCT03971409) https://adis.springer.com/drugs/800041802).

However, this antibody has not been used or proposed for use in the treatment of COVID-19.

It will also be understood by one skilled in the art that, instead of an antibody that is an OX40 receptor agonist, an antigen-binding fragment thereof may be used in accordance with the present invention.

The term "antigen-binding fragment of an antibody" refers to a fragment that at least has antigen-binding capacity and is a Fab, F(ab'), F(ab')2, Fv or similar fragment.

Fab refers to a structure comprising the variable region of each of the heavy chain and light chain, the constant region of the light chain, and the first constant domain (CH1) of the heavy chain, each of which has one antigen-binding site.

Fab' differs from Fab in that it additionally includes a hinge region comprising at least one cysteine residue at the C-terminus of the CH1 domain of the heavy chain.

F(ab')2 is formed by a disulfide bond between cysteine residues in the hinge region of Fab'.

Fv is a minimal antibody fragment having only a heavy chain variable region and a light chain variable region, recombinant technology for producing Fv is disclosed in international PCT publications such as WO 88/10649, WO 88/106630, WO 88/07085, WO 88/07086 and WO 88/09344.

A double-chain Fv is a fragment in which the variable region of the heavy chain and the variable region of the light chain are linked by a non-covalent bond, and a single-chain Fv (scFv) is a fragment in which the variable region of the heavy chain and the variable region of the light chain are usually linked by a covalent bond through a peptide linker between them or directly linked at the C-terminus to form a dimer-like structure such as a double-chain Fv.

Such antibody fragments can be produced using proteases (e.g., Fab can be produced by restriction digestion of the whole antibody with papain, and the F(ab')2 fragment can be produced by restriction digestion of the whole antibody with pepsin) or by recombinant DNA technology.

In one embodiment of the present invention, the constant region of the heavy chain of the antibody can be selected from the isotypes gamma (γ), mu (μ), alpha (α), delta (δ) and epsilon (ε). For example, the constant region can be gamma 1 (IgG1), gamma 3 (IgG3) or gamma 4 (IgG4). The constant region of the light chain can be kappa or lambda.

As natural or artificial OX40 receptor ligands - OX40L for use in accordance with the present invention, there can be used, for example, the OX40 receptor ligands - OX40L disclosed in Short-Term Local Expression of a PD-L1 Blocking Antibody from a Self-Replicating RNA Vector Induces Potent Antitumor Responses. Ballesteros-Briones MC, Martisova E, Casales E, Silva-Pilipich N, Buñuales M, Galindo J, Mancheño U, Gorraiz M, Lasarte JJ, Kochan G, Escors D, Sanchez-Paulete AR, Melero I, Prieto J, Hernandez-Alcoceba R, Hervas-Stubbs S, Smerdou C. Mol Ther. 2019 Nov 6;27(11):1892-1905. doi: 10.1016/j.ymthe.2019.09.016. Epub 2019 Sep 16. PMID: 31563534; Regulation of T cell activation in vitro and in vivo by targeting the OX40-OX40 ligand interaction: amelioration of ongoing inflammatory bowel disease with an OX40-IgG fusion protein, but not with an OX40 ligand-IgG fusion protein. Higgins LM, McDonald SA, Whittle N, Crockett N, Shields JG, MacDonald TT. J Immunol. 1999 Jan 1;162(1):486-93. PMID: 9886424 Free article; Anti-CD73 and anti-OX40 immunotherapy coupled with a novel biocompatible enzyme prodrug system for the treatment of recurrent, metastatic ovarian cancer. Virani NA, Thavathiru E, McKernan P, Moore K, Benbrook DM, Harrison RG. Cancer Lett. 2018 Jul 1;425:174-182. doi: 10.1016/j.canlet.2018.03.027. Epub 2018 Mar 21. PMID: 29574275; Blockade of OX40/OX40 ligand to decrease cytokine messenger RNA expression in acute renal allograft rejection in vitro. Wang YL, Li G, Fu YX, Wang H, Shen ZY. Transplant Proc. 2013 Jul-Aug;45(6):2565-8. doi: 10.1016/j.transproceed.2013.03.038. PMID: 23953582; IL-15 controls T cell functions through its influence on CD30 and OX40 antigens in Celiac Disease. Periolo N, Guillén L, Arruvito ML, Alegre NS, Niveloni SI, Hwang JH, Bai JC, Cherñavsky AC. Cytokine. 2014 May;67(1):44-51. doi: 10.1016/j.cyto.2014.01.004. Epub 2014 Mar 14. PMID: 24680481; Requirements for the functional expression of OX40 ligand on human activated CD4+ and CD8+ T cells. Kondo K, Okuma K, Tanaka R, Zhang LF, Kodama A, Takahashi Y, Yamamoto N, Ansari AA, Tanaka Y. Hum Immunol. July 2007; 68(7):563-71. doi: 10.1016/j.humimm.2007.03.012. Epub 2007 Apr 13. PMID: 17584577; Molecular transfer of CD40 and OX40 ligands to leukemic human B cells induces expansion of autologous tumor-reactive cytotoxic T lymphocytes. Biagi E, Dotti G, Yvon E, Lee E, Pule M, Vigouroux S, Gottschalk S, Popat U, Rousseau R, Brenner M. Blood. 2005 Mar 15;105(6):2436-42. doi: 10.1182/blood-2004-07-2556. Epub 2004 Nov 9. PMID: 15536147; Fc-mOX40L fusion protein produces complete remission and enhanced survival in 2 murine tumor models. Sadun RE, Hsu WE, Zhang N, Nien YC, Bergfeld SA, Sabzevari H, Lutsiak ME, Khawli L, Hu P, Epstein AL. J Immunother. 2008 Apr;31(3):235-45. doi: 10.1097/CJI.0b013e31816a88e0. PMID: 18317364.

The OX40 receptor agonist of the present invention may be administered either alone or in combination with other agents for the treatment of severe COVID-19, which may not necessarily be other OX40 receptor agonists or have other biological activity useful for the treatment of COVID-19.

For example, the PF-8600 antibody of the present invention may be administered either alone or in combination with other monoclonal antibodies being tested for the treatment of severe COVID-19, which may not necessarily be OX40 receptor agonists or have other biological activity useful for the treatment of COVID-19.

Preferably, according to the present invention, the antibody PF-8600 can be co-administered with utomilumab (PF-05082566), an agonist monoclonal antibody to the tumor necrosis factor superfamily receptor 4-1BB, since both receptors play a key role in the survival, proliferation and activation of T cells, which may be useful for the treatment of COVID-19. The combination of the antibody PF-8600 and utomilumab is currently being tested for the treatment of patients with cancer.

In general and generally, in accordance with the present invention, when using an OX40 receptor agonist together with at least one other agent for alleviating, treating or preventing severe COVID-19, the OX40 receptor agonist and at least one other agent for treating severe COVID-19 are administered either sequentially or simultaneously.

For example, the PF-8600 antibody according to the present invention can be administered in combination with the PF-05082566 antibody, as described in WO2017130076A1, 03.08.2017.

When administered simultaneously, said antibodies can be administered via the same pharmaceutical composition containing said antibodies.

To implement the present invention, a medicinal product that acts on CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, can be administered to the individual by any suitable method of administering the medicinal product known in the art.

In certain embodiments of the present invention, a medicament that acts on CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with SARS-CoV-2 coronavirus, can be administered to the individual by any suitable enteral or parenteral route of administration.

Enteral route of administration in accordance with the present invention means administration via any part of the gastrointestinal tract. Examples of enteral routes include the oral, mucosal, buccal and rectal route or the intragastric route.

Parenteral administration refers to administration other than enteral administration. Examples of parenteral routes of administration include intrapulmonary, intravenous, intramuscular, intradermal, intraperitoneal, intravesical, intraarterial, intrathecal, intraorbital, intracardiac, transtracheal, intra-articular, subarachnoid, intraspinal, epidural, intrasternal, and subcutaneous.

The appropriate route and the appropriate mode of administration may vary depending on a number of factors, such as the particular drug that acts on the CD8+ memory T lymphocytes to coronavirus infections that preceded the SARS-CoV-2 coronavirus infection in the individual, that are activated in the individual upon infection with the SARS-CoV-2 coronavirus, the desired absorption rate, the particular composition and dosage form used, the condition of the individual, and can be readily selected by one of skill in the art.

Specialists in this field of technology are well aware not only of the methodology for each of the indicated methods of administering a medicinal product, but also of the medicinal forms and compositions suitable for such methods of administration, as well as the methods for their preparation.

In order to provide a medicinal product that acts on CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, in a dosage form suitable for the selected route of administration, said medicinal product can be preliminarily provided in the form of a suitable pharmaceutical composition, for example, by mixing the active ingredient, i.e. the OX40 receptor agonist, with appropriate pharmaceutically acceptable substances for the preparation of pharmaceutical compositions.

The qualitative and quantitative composition of a pharmaceutical composition, which is a medicinal product that affects CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, and the methods for preparing such compositions depend not only on the selected route of administration, but also on a number of other parameters, including, without limitation, the physicochemical and pharmaceutical properties of the active ingredient that affects CD8+ T lymphocytes of memory to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, the severity of the disease, the administration regimen and dosage.

The pharmaceutical composition for use in accordance with the present invention may take any of a number of different dosage forms that can be used to treat a human or animal. For example, it may be in the form of a powder, concentrate, solution, tablet, capsule, ointment, cream, gel, aerosol, spray, transdermal patch, suspension.

The pharmaceutically acceptable carrier may be any known compound or combination of known compounds that are known to those skilled in the art to be useful in the manufacture of pharmaceutical compositions. The carrier may be a binder, a coating, a disintegrating agent, a filler or diluent, a preservative (e.g., an antioxidant, antibacterial or antifungal agent), a sweetener, an absorption delaying agent, a wetting agent, an emulsifying agent, a buffer, and the like. Examples of suitable pharmaceutically acceptable carriers include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), dextrose, vegetable oils (such as olive oil), saline, buffer, buffered saline, and isotonic agents such as sugars, polyhydric alcohols, sorbitol, and sodium chloride.

It should be understood that the carrier of the pharmaceutical composition must be tolerated by the individual in whom it is administered.

In one embodiment of the present invention, the pharmaceutically acceptable carrier may be solid, and the pharmaceutical composition may be in solid form. Examples of solid dosage forms include tablet, pill, capsule, microcapsule and powder.

In another embodiment of the present invention, the pharmaceutically acceptable carrier may be a liquid, and the pharmaceutical composition may be in the form of a solution, suspension, emulsion, microemulsion, liposomes, dispersion or other liquid form known to one skilled in the art.

Liquid pharmaceutical compositions according to the invention, which are sterile solutions or suspensions, can be administered, for example, by intramuscular, intrathecal, epidural, intraperitoneal, intravenous and subcutaneous injection.

The pharmaceutical composition can be prepared as a sterile solid composition that can be dissolved or suspended prior to administration using sterile water, saline or other suitable sterile injection medium.

Sterile solutions can be prepared by incorporating an OX40 receptor agonist, such as an antibody, in the required amount in an appropriate carrier, followed by sterilizing microfiltration. Typically, dispersions are prepared by incorporating the antibody into a sterile carrier that contains a basic dispersion medium and other carriers. In the case of sterile powders for the preparation of a sterile liquid, the preparation methods include vacuum drying and lyophilization.

The relative amount of OX40 receptor agonist included in the pharmaceutical composition as the active principle according to the present invention will vary depending on a number of factors, such as the particular molecule used as the OX40 receptor agonist, the carriers used, the dosage form and the desired release dynamics.

The amount of OX40 receptor agonist in a single dose formulation should be such that it produces a therapeutic effect.

A therapeutically effective amount of an OX40 receptor agonist depends on a number of parameters, including the magnitude of the agnostic activity of the substance used as an OX40 receptor agonist, the age and gender of the individual, the severity of the disease, the presence of concomitant diseases, and other factors that are commonly taken into account in the art when determining a therapeutically effective dose of a drug.

When the OX40 receptor agonist is the antibody PF-8600, it is preferably administered according to the present invention every two weeks at a dose selected from the group consisting of 0.01 mg/kg, 0.03 mg/kg, 0.1 mg/kg, 0.3 mg/kg, 1 mg/kg, 1.5 mg/kg, 3 mg/kg, 5 mg/kg and 10 mg/kg, which corresponds to the dosages and regimens proposed for use in the treatment of cancer using said antibody. Other known regimens and dosages of this antibody suitable for the treatment of cancer can also be used, since they are entirely safe and effective for use in accordance with the present invention.

Typically, the amount of OX40 receptor agonist in the dosage form will be in the range of from about 0.01 percent to about 99 percent, from about 0.1 percent to about 70 percent, or from about 1 percent to about 30 percent, based on the total weight of the dosage form.

In addition to the OX40 receptor agonist, one or more additional therapeutic agents for the treatment of severe disease caused by SARS-CoV-2 coronavirus infection may be included in the pharmaceutical composition of the invention, which may optionally be other OX40 receptor agonists or have other biological activity useful for the treatment of disease caused by SARS-CoV-2 coronavirus infection.

For example, a pharmaceutical composition of the invention comprising the antibody PF-8600 may further comprise at least one other monoclonal antibody being tested for the treatment of a severe disease caused by infection with the coronavirus SARS-CoV-2, which may optionally be an OX40 receptor agonist or have other biological activity useful for the treatment of a disease caused by infection with the coronavirus SARS-CoV-2.

Preferably, according to the present invention, the pharmaceutical composition of the invention containing the antibody PF-8600 further comprises utomilumab (PF-05082566).

The appropriate amount of additional therapeutic agent to include in the composition of the invention can be readily selected by one of skill in the art and will vary depending on a number of factors such as the particular additional therapeutic agent used, the particular carriers used, the dosage form selected, and the desired release profile.

The amount of additional therapeutic agent included in a dosage form for single dose administration will generally be that amount which produces a therapeutic effect.

A medicinal product that acts on CD8+ T lymphocytes memory to coronavirus infections preceding infection with coronavirus SARS-CoV-2 in an individual, activated in said individual upon infection with coronavirus SARS-CoV-2, as defined above in this document, i.e. that is or contains an OX40 receptor agonist, in accordance with the method of acting on CD8+ T lymphocytes memory to coronavirus infections preceding infection with coronavirus SARS-CoV-2 in an individual, as defined above in this document, can be used to alleviate, treat or prevent a severe course of a disease caused by infection with coronavirus SARS-CoV-2 in this individual or to obtain or manufacture a medicinal product for alleviating, treating or preventing a severe course of a disease caused by infection with coronavirus SARS-CoV-2. Moreover, the said medicine can be obtained or produced taking into account the guidelines provided above in this document for obtaining pharmaceutical compositions and dosage forms containing an OX40 receptor agonist, as well as using methods known in this field of technology for obtaining pharmaceutical compositions and dosage forms.

In one of the preferred embodiments of the present invention, such a medicinal product is the antibody PF-8600, or an antigen-binding fragment thereof, or a pharmaceutical composition comprising said antibody or an antigen-binding fragment thereof, since, as established by the authors of the present invention, the antibody PF-8600 can exert the effect defined above in this document on CD8+ T lymphocytes memory to coronavirus infections preceding infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus.

Accordingly, the antibody PF-8600, or its antigen-binding fragment, or a pharmaceutical composition comprising said antibody or its antigen-binding fragment is one of the most preferred means for use in influencing CD8+ memory T lymphocytes to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with the SARS-CoV-2 coronavirus, as defined herein above.

The use of the present invention is particularly useful in patients with an inadequate immune response to infection with the SARS-CoV-2 coronavirus, as defined above in this document, for generating an adequate immune response, where by generating an adequate immune response in accordance with the present invention is meant at least one of the following:

- stimulation of CD8+ T memory lymphocytes to coronavirus infections that preceded infection with the SARS-CoV-2 coronavirus in an individual, activated in the said individual upon infection with the SARS-CoV-2 coronavirus, and an increase in their activity in relation to SARS-CoV-2 antigens;

- reduction of the level of apoptosis of these lymphocytes;

- reduction of the death rate of these lymphocytes;

- induction of increased activity of these lymphocytes in relation to SARS-CoV-2 antigens;

- increased migration of these lymphocytes to the source of antigen production, i.e. to tissues affected by the SARS-CoV-2 virus;

- a decrease in the ability of these lymphocytes to activate apoptosis in lymphocytes with high avidity for the SARS-CoV-2 virus;

- a decrease in the ability of these lymphocytes to initiate the death of lymphocytes that are highly avid to the SARS-CoV-2 virus;

- stimulation of the destruction of cells affected by the SARS-CoV-2 virus;

- increasing the efficiency of elimination of the SARS-CoV-2 virus.

In this embodiment of the present invention, an individual as defined herein above, according to the method or use of the invention aimed at correcting an inadequate response and generating an adequate response in patients with an inadequate immune response to infection with the coronavirus SARS-CoV-2, can be administered an effective amount of a medicament that affects the memory CD8+ T lymphocytes to coronavirus infections that preceded the infection with the coronavirus SARS-CoV-2 in the individual, activated in said individual upon infection with the coronavirus SARS-CoV-2, as defined herein above, i.e. representing or containing an OX40 receptor agonist, as defined herein above.

The said effective amount should be sufficient to correct an inadequate immune response to infection with the SARS-CoV-2 coronavirus and to generate an adequate immune response as defined herein above.

In a preferred embodiment of the present invention, said effective amount corresponds to an effective amount required to affect CD8+ T lymphocytes memory to coronavirus infections that preceded infection with SARS-CoV-2 coronavirus in an individual, activated in said individual upon infection with SARS-CoV-2 coronavirus, as defined above in this document.

According to this embodiment of the invention, suitable routes of administration, dosage forms, pharmaceutical compositions, regimens and doses for use in patients with an inadequate immune response to infection with the SARS-CoV-2 coronavirus are preferably as described above herein.

The following examples are provided, which are intended to facilitate understanding of the essence of the present invention, but not to limit the present invention, since, based on the disclosure of the present invention, various embodiments thereof will be obvious to a person skilled in the art, not directly described in this document, but implied and covered by the claims, taking into account the information known in the art and the usual skills of a specialist.

Example 1

A composition containing a monoclonal antibody that is an OX40 receptor agonist for use in accordance with the present invention can be obtained in accordance with RU2518278C2, 10.06.2014, and can have any composition from those presented in Table 1

Composition number pH monoclonal antibody that is an OX40 receptor agonist (mg/ml) Histidine mM Trehalose (mg/ml) PS20 (mg/ml) Methionine (mg/ml) EDTA (mg/ml) 1 6.0 50 10 84 0,1 - - 2 6.0 50 10 84 0,1 - 0.05 3 6.0 50 10 84 0,1 0,1 - 4 6.0 50 10 84 0,1 0,1 0.05 5 6.0 10 10 84 0,1 0,1 0.05

Example 2

According to the present invention, a patient with a severe course of the disease caused by infection with the SARS-CoV-2 virus is administered the monoclonal antibody PF-04518600, as monotherapy or in combination with other drugs (as described, for example, in WO2017130076A1) at a dose of 0.3 to 3 mg/kg intravenously once every two weeks, since such doses of the drug and the administration regimen have been shown to be satisfactorily tolerated and lead to a significant increase in the expression of the OX40 receptor and other functional markers of T-lymphocytes (Hamid, S. Hu-Lieskovan, W. Ros, A. Diab, A.B. El-Khoueiry, J.A. Thompson, F.A. Eskens, J.-P. Spano, E. Angevin, N.A. Rizvi, J.S. Wasser, P.A. Ott, A. Chiappori, T. Joh, H.I. Krupka, S. Potluri, X. Wang, B.J. Ganguli, J. Chou, T. Doi Open Archive DOI: https://doi.org/10.1093/annonc/mdy288.057).

Since the leading pathway for the development of severe COVID-19 is the immune system's response to the SARS-CoV-2 virus, caused by immunological memory to previous coronavirus infections caused by coronaviruses other than the SARS-CoV-2 coronavirus, its negative manifestations can be eliminated in the patient by stimulating the OX40 (CD134) receptor with the monoclonal antibody PF-04518600.

Although the embodiment of the present invention is demonstrated using the monoclonal antibody PF-04518600, given the information disclosed herein, it will be obvious to those skilled in the art that other natural or artificial OX40 receptor agonists can be used as OX40 receptor agonists for the treatment or prevention of severe disease caused by infection with the SARS-CoV-2 virus.

Claims (16)

1. The use of a medicinal product that acts on memory CD8+ T lymphocytes to coronavirus infections preceding infection with the SARS-CoV-2 coronavirus in an individual, where said CD8+ T lymphocytes are activated in said individual upon infection with the SARS-CoV-2 coronavirus, to correct an inadequate immune response to infection with the SARS-CoV-2 coronavirus in said individual or to generate an adequate immune response to said infection in said individual, wherein the effect on CD8+ T lymphocytes of memory to coronavirus infections preceding infection with coronavirus SARS-CoV-2 in an individual, activated in said individual upon infection with coronavirus SARS-CoV-2, comprises one of the following: - stimulation of these lymphocytes and increasing their activity in relation to SARS-CoV-2 antigens; - reduction of the level of apoptosis of these lymphocytes; - reduction of the death rate of these lymphocytes; - induction of increased activity of these lymphocytes in relation to SARS-CoV-2 antigens; - increased migration of these lymphocytes to the source of antigen production, i.e. to tissues affected by the SARS-CoV-2 virus; - a decrease in the ability of these lymphocytes to activate apoptosis in lymphocytes with high avidity for the SARS-CoV-2 virus; - a decrease in the ability of these lymphocytes to initiate the death of lymphocytes that are highly avid to the SARS-CoV-2 virus; - stimulation of the destruction of cells affected by the SARS-CoV-2 virus; - increasing the efficiency of elimination of the SARS-CoV-2 virus, where the inappropriate immune response is an immune response that is caused by or consists of stimulating the proliferation of CD8+ T lymphocytes in that individual to precursor coronaviruses characterized by reduced avidity for the SARS-CoV-2 coronavirus, increased levels of intrinsic apoptosis, and stimulating activity against apoptosis of high-avidity CD8+ T lymphocytes. 2. Use according to claim 1, wherein said medicinal product is an OX40 receptor agonist. 3. The use according to claim 2, wherein the OX40 receptor agonist is the antibody PF-04518600. 4. Use according to any of paragraphs 1-3, according to which the medicinal product is used together with another therapeutic agent useful for the treatment of a severe course of the disease caused by the SARS-CoV-2 coronavirus infection, or said medicinal product additionally contains said other therapeutic agent useful for the treatment of a severe course of the disease caused by the SARS-CoV-2 coronavirus infection. 5. The use according to claim 4, wherein said other therapeutic agent useful for the treatment of severe disease caused by SARS-CoV-2 coronavirus infection is utomilumab (PF-05082566).