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EP-4739344-A2 - FUSION PROTEINS CONTAINING IL21 MUTEINS FOR TREATING CANCER AND VIRAL DISEASES

EP4739344A2EP 4739344 A2EP4739344 A2EP 4739344A2EP-4739344-A2

Abstract

A fusion protein includes an anti-PD1 antibody portion having a C-terminus, and an IL21 mutein conjugated with the anti-PD1 antibody portion with its C-terminus, wherein the IL21 mutein contains at least one of the two mutations relative to the wild-type IL21: (1) one of K72Y substitution, K72M substitution, and K72Q substitution, and (2) 75-80 deletion. In some examples, the anti-PD1 antibody can adopt a ETYY format, and can include a first heavy chain comprising a VH comprising a sequence of SEQ ID NO:11, and a second heavy chain comprising a VH comprising a sequence selected from the sequences of SEQ ID NOS:8-10. Pharmaceutical compositions including the fusion protein, nucleic acid coding the fusion protein, vectors including the nucleic acid, and methods of treating diseases using the fusion protein are also provided.

Inventors

  • JAVANBAKHT, Hassan
  • RAMOS, Hilario J.
  • LIU, YUE
  • HOAG, Matthew
  • WANG, BO

Assignees

  • Bluejay Therapeutics, Inc.

Dates

Publication Date
20260513
Application Date
20240702

Claims (20)

  1. 1. A fusion protein comprising an anti-PDl antibody portion having a C-terminus, and an IL21 mutein conjugated with the anti-PDl antibody portion with its C-terminus, wherein the IL21 mutein contains at least one of the two mutations relative to the wild-type human IL21: (1) one of K72Y substitution, K72M substitution, and K72Q substitution, and (2) 75-80 deletion.
  2. 2. The fusion protein of claim 1, wherein the IL21 mutein contains both of (1) one of K72Y substitution, K72M substitution, and K72Q substitution, and (2) 75-80 deletion.
  3. 3. The fusion protein of claim 1, wherein the anti-PDl antibody has an IgGl format and comprises a first heavy chain and second heavy chain, the first heavy chain comprising a T366Y mutation and the second heavy chain comprising a Y407T mutation.
  4. 4. The fusion protein of claim 1, wherein the anti-PDl antibody has an IgGl format and comprises a first heavy chain and second heavy chain, the first heavy chain containing K360, S354Y and T366Y mutations, and the second heavy chain containing G347E, Y349 and Y407T mutations.
  5. 5. The fusion protein of claim 1, wherein the anti-PDl antibody comprises a first heavy chain comprising a VH comprising a sequence of SEQ ID NO:7.
  6. 6. The fusion protein of claim 5, wherein the anti-PDl antibody further comprises a second heavy chain comprising a VH comprising a sequence selected from the group consisting of the sequences of SEQ ID NOS:8-10.
  7. 7. The fusion protein of claim 1 , wherein the anti-PDl antibody comprises a first heavy chain comprising a VH comprising a sequence of SEQ ID NO:11.
  8. 8. The fusion protein of claim 7, wherein the anti-PDl antibody further comprises a second heavy chain comprising a VH comprising a sequence selected from the group consisting of the sequences of SEQ ID NOS:8-10.
  9. 9. The fusion protein of any of claims 3-8, wherein the first heavy chain includes the sequence of SEQ ID NO: 13, and the second heavy chain includes the sequence of SEQ ID NO: 12.
  10. 10. The fusion protein of claim 9, wherein only the first heavy chain is conjugated with the IL21 mutein and the second heavy chain is not conjugated with any IL21 mutein.
  11. 11. The fusion protein of claim 1, wherein the anti-PDl antibody portion and the IL21 mutein are conjugated via a linker.
  12. 12. The fusion protein of claim 11, wherein the linker comprises (G n S) x , wherein n is an integer between 2 and 4 inclusive, x is an integer between 1 and 4 inclusive.
  13. 13. The fusion protein of claim 1, wherein the anti-PDl antibody portion is directly connected to the IL21 mutein.
  14. 14. The fusion protein of claim 9, wherein the first heavy chain comprises the sequence selected from the groups consisting of SEQ ID NOS:17-22.
  15. 15. The fusion protein of claim 14, wherein the second heavy chain comprises the sequence set forth in SEQ ID NO: 16.
  16. 16. A nucleic acid encoding the fusion protein of any of claims 1-15.
  17. 17. A vector comprising the nucleic acid of claim 16.
  18. 18. A pharmaceutical composition comprising a fusion protein of any of claims 1-15 and a pharmaceutically acceptable carrier.
  19. 19. A method of treating a cancer of a subject, comprising administering to the subject an effective amount of a fusion protein of any of claims 1-15 or of the pharmaceutical composition of claim 18.
  20. 20. The method of claim 19, wherein the cancer is a solid tumor, a hematological malignancy, or a lymphoid malignancy.

Description

FUSION PROTEINS CONTAINING IL21 MUTEINS FOR TREATING CANCER AND VIRAL DISEASES BACKGROUND Interleukin-21 (IL-21, or IL21) is a pleiotropic cytokine belonging to the common gamma chain (yc) family, with critical roles in the regulation of both innate and adaptive immune responses. Discovered in 2000, IL-21 is mainly produced by activated CD4+ T cells, particularly T follicular helper (Tfh) cells and natural killer T (NKT) cells, and acts on various immune cell types, including T cells, B cells, NK cells, and dendritic cells. This cytokine has been implicated in modulating numerous immunological processes, such as T cell differentiation, B cell proliferation, and antibody production, as well as enhancing cytotoxic activity of NK cells. The potential therapeutic applications of IL-21 have attracted significant attention in recent years, with a focus on its capacity to modulate immune responses in the context of chronic viral infections and cancer. Chronic hepatitis B virus (HBV) infection remains a major public health issue, affecting millions of individuals worldwide and causing significant morbidity and mortality due to liver cirrhosis and hepatocellular carcinoma. Current antiviral therapies, including nucleos(t)ide analogs and interferon-alpha, have limited efficacy in achieving a functional cure for the majority of patients. IL-21 has emerged as a promising candidate for the treatment of chronic HBV infection, given its ability to boost antiviral immune responses and promote viral clearance. Studies have demonstrated that IL-21 can enhance the function of HBV-specific T cells, augmenting their proliferation, cytotoxic activity, and cytokine production. Moreover, IL-21 has been shown to suppress HBV replication in human hepatocytes and animal models, highlighting its potential as a novel therapeutic agent for achieving a functional cure in chronic HBV patients. IL-21 has also shown promise in the field of oncology, given its capacity to stimulate potent antitumor immune responses. Preclinical studies have demonstrated that IL-21 can enhance the cytotoxic activity of NK cells and CD8+ T cells, leading to the eradication of tumor cells in various cancer models. In addition, IL-21 can promote the differentiation of T cells towards a Thl phenotype, which is associated with improved antitumor immunity. Clinical trials investigating the safety and efficacy of IL-21 as a monotherapy or in combination with other immunotherapies have shown encouraging results in patients with metastatic melanoma and renal cell carcinoma. Further research is needed to fully elucidate the therapeutic potential of IL- 21 in cancer and to optimize its application in combination with other emerging immunotherapeutic approaches. IL-21 has also emerged as a potential therapeutic agent for human immunodeficiency virus (HIV) infection, due to its immunomodulatory properties and ability to enhance the function of virus-specific immune responses. HIV infection is characterized by progressive CD4+ T cell depletion, immune dysregulation, and the establishment of a viral reservoir, which presents a major barrier to achieving a functional cure. Research has demonstrated that IL-21 can promote the survival, proliferation, and function of CD4+ and CD8+ T cells in HIV-infected individuals, as well as boost the cytotoxic activity of NK cells, thereby enhancing antiviral immunity. Additionally, IL-21 has been shown to exert a direct antiviral effect on HIV replication in vitro, and its administration in simian immunodeficiency virus (SIV) -infected non-human primates resulted in reduced viral loads and improved immune reconstitution. These findings suggest that IL-21 may hold promise as a novel immunotherapeutic approach for the treatment of HIV, either alone or in combination with antiretroviral therapy and other immune-based interventions. SUMMARY In one aspect of the disclosed subject matter, a fusion protein is provided, which comprises an anti-PDl antibody portion having a C-terminus, and an IL21 mutein conjugated with the anti-PDl antibody portion with its C-terminus, wherein the IL21 mutein contains one or both of the following mutations relative to the wild-type IL21: (1) one of K72Y substitution, K72M substitution, and K72Q substitution, and (2) 75-80 deletion. For example, the IL21 mutein can comprise an amino acid sequence selected from the group consisting of SEQ ID NOS:2-6. In some embodiments of the fusion protein, the IL21 mutein contains both of (1) one of K72Y substitution, K72M substitution, and K72Q substitution, and (2) 75-80 deletion. In some embodiments, the IL21 mutein only contains one of the two mutations relative to the wild-type IL21 : (1) one of K72Y substitution, K72M substitution, and K72Q substitution, and (2) 75-80 deletion. In some embodiments, the anti-PDl antibody has an IgGl format and comprises a first heavy chain and second heavy chain, the first heavy chain comprising a T366Y mutation and the second heavy cha