SIRP-ALPHA VARIANT CONSTRUCTS AND USES THEREOF

• US 20160186150A1
• Filed: 12/16/2015
• Published: 06/30/2016
• Est. Priority Date: 08/08/2014
• Status: Abandoned Application

• Current Assignee: Alexo Therapeutics International (ALX Oncology Holdings, Inc.)
• Original Assignee: Alexo Therapeutics International (ALX Oncology Holdings, Inc.)
• Inventors: Deming, Laura, Goodman, Corey, Sim, Bang Janet, Pons, Jaume, Vrljic, Marija
• Application Number:
  US14/971,931
• Publication Number:
  US 20160186150A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: A61K 47/64 Drug-peptide, drug-protein or drug-polyamino acid conjugates, i.e. the modifying agent being a peptide, protein or polyamino acid which is covalently bonded or complexed to a therapeutically active agent peptidic linkers A61K47/65
• CPC Class Codes: A61K 47/643 Albumins, e.g. HSA, BSA, ovalbumin or a Keyhole Limpet Hemocyanin [KHL]
• CPC Class Codes: A61K 47/65 Peptidic linkers, binders or spacers, e.g. peptidic enzyme-labile linkers
• CPC Class Codes: A61K 47/6803 Drugs conjugated to an antibody or immunoglobulin, e.g. cisplatin-antibody conjugates
• CPC Class Codes: A61K 47/6811 the drug being a protein or peptide, e.g. transferrin or bleomycin
• CPC Class Codes: A61K 47/6815 Enzymes
• CPC Class Codes: A61K 47/6849 the antibody targeting a receptor, a cell surface antigen or a cell surface determinant
• CPC Class Codes: A61K 47/6851 the antibody targeting a determinant of a tumour cell
• CPC Class Codes: A61K 47/6871 the antibody targeting an enzyme
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 37/02 Immunomodulators
• CPC Class Codes: C07K 14/4703 Inhibitors; Suppressors
• CPC Class Codes: C07K 14/70503 Immunoglobulin superfamily
• CPC Class Codes: C07K 2319/74 containing a fusion for binding to a cell surface receptor
• CPC Class Codes: C12N 9/16 acting on ester bonds (3.1)
• CPC Class Codes: C12Y 301/03048 Protein-tyrosine-phosphatase (3.1.3.48)

Abstract

The invention relates to compositions and methods of constructs comprising a SIRP-α polypeptide, including SIRP-α variants. The constructs may be engineered in a variety of ways to respond to environmental factors, such as pH, hypoxia, and/or the presence of tumor-associated enzymes or tumor-associated antigens. The constructs of the invention may be used to treat various diseases, such as cancer, preferably solid tumor or hematological cancer.

Claims

1. A construct comprising a SIRP-α

polypeptide or a fragment thereof, wherein said SIRP-α

polypeptide or said fragment thereof preferentially binds CD47 on diseased cells or at a diseased site as compared to CD47 from non-diseased cells or at a non-diseased site.

2. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof binds to CD47 on diseased cells or at a diseased site with a higher affinity than it binds CD47 on non-diseased cells.

3. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof is attached to a blocking peptide.

4. The construct of claim 3, wherein said blocking peptide binds with higher affinity to a wild-type SIRP-α

than to said SIRP-α

polypeptide or a fragment thereof.

5. The construct of claim 3, wherein said SIRP-α

polypeptide or a fragment thereof binds with higher affinity to a wild-type CD47 than to said blocking peptide.

6. The construct of claim 3, wherein said blocking peptide is a CD47-based blocking peptide.

7. The construct of claim 6, wherein said CD47-based blocking peptide has at least 80% amino acid sequence identity to the sequence of the wild-type, IgSF domain of CD47 (SEQ ID NO:

35), or a fragment thereof.

8. The construct of claim 7, wherein said CD47-based blocking peptide has the sequence of SEQ ID NO:

36, 37, 38, 39, 40, 41, 42, 43, 44, 45, or 46.

9. The construct of claim 3, wherein said SIRP-α

polypeptide or a fragment thereof is attached to said blocking peptide by a cleavable linker and optionally one or more spacers.

10. The construct of claim 9, wherein said cleavable linker is cleaved under acidic pH and/or hypoxic conditions.

11. The construct of claim 9, wherein said cleavable linker is cleaved by a tumor-associated enzyme.

12. The construct of claim 11, wherein said tumor-associated enzyme is a protease.

13. The construct of claim 12, wherein said protease is selected from the group consisting of matriptase (MTSP1), urinary-type plasminogen activator (uPA), legumain, PSA (also called KLK3, kallikrein-related peptidase-3), matrix metalloproteinase-2 (MMP-2), MMP-9, human neutrophil elastase (HNE), and proteinase 3 (Pr3).

14. The construct of claim 9, wherein said cleavable linker has the sequence of L/S/G/R/S/D/N/H (SEQ ID NO:

47);

/Kr/RKQ/gAS/RK/A (SEQ ID NO;

     76);

---/--/-/N/-/-/- (SEQ ID NO;

     78);

SI/SQ/-/YQR/S/S/-/- (SEQ ID NO;

     81);

S/S/K/L/Q (SEQ ID NO;

     82);

-/P/-/-/LI/-/-/- (SEQ ID NO;

     83);

G/P/L/G/I/A/G/Q (SEQ ID NO;

     85);

P/V/G/L/I/G (SEQ ID NO;

     86);

H/P/V/G/L/L/A/R (SEQ ID NO;

     87);

-/-/-/VIAT/-/-/-/- (SEQ ID NO;

     88);

-/Y/Y/VTA/-/-/-/- (SEQ ID NO;

     89);

PRFKIIGG (SEQ ID NO;

     90);

PRFRIIGG (SEQ ID NO;

     91);

SSRHRRALD (SEQ ID NO;

     92);

RKSSIIIRMRDVVL (SEQ ID NO;

     93);

SSSFDKGKYKKGDDA (SEQ ID NO;

     94);

SSSFDKGKYKRGDDA (SEQ ID NO;

     95);

IEGR (SEQ ID NO;

95A);

IDGR (SEQ ID NO;

     96);

GGSIDGR (SEQ ID NO;

     97);

PLGLWA (SEQ ID NO;

     98);

or DVAQFVLT (SEQ ID NO;

     99).

15. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof is attached to an antibody-binding peptide.

16. The construct of claim 15, wherein said antibody-binding peptide binds to a constant region of an antibody reversibly or irreversibly or to a fragment antigen-binding (Fab) region of an antibody reversibly or irreversibly or to a variable region of an antibody reversibly or irreversibly.

17. The construct of claim 15, wherein said antibody-binding peptide has at least 75% amino acid sequence identity to the sequence of a disease localization peptide (DLP) (SEQ ID NO:

64, 65 or

     66).

18. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof is attached to an Fc domain monomer, an Fc domain, a human serum albumin (HSA), an albumin binding peptide or a polymer, wherein said polymer comprises a polyethylene glycol (PEG) chain or a polysialic acid chain.

19. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof is attached to an antibody or a fragment thereof.

20. The construct of claim 19, wherein said antibody binds to one or more of the following:

4-1BB, 5T4, ALK1, ANG-2, B7-H3, B7-H4, c-Met, CA6, CCR4, CD123, CD19, CD20, CD22, CD27, EpCAM, CD30, CD32b, CD33, CD37, CD38, CD40, CD52, CD70, CD74, CD79b, CD98, CEA, CEACAM5, CLDN18.2, CLDN6, CS1, CTLA-4, CXCR4, DLL-4, EGFR, EGP-1, ENPP3, EphA3, ETBR, FGFR2, fibronectin, FR-alpha, frizzled receptor, GCC, GD2, glypican-3, GPNMB, HER2, HER3, HLA-DR, ICAM-1, IGF-1R, IL-3R, LIV-1, mesothelin, MUC16, MUC1, NaPi2b, Nectin-4, Notch 2, Notch 1, OX-40, PD-1, PD-L1, PD-L2, PDGFR-α

, PS, PSMA, SLTRK6, STEAP1, TEM1, VEGFR, CD25, DKK-1, and/or CSF-1R.

21. The construct of claim 19, wherein said antibody is cetuximab, necitumumab, pembrolizumab, nivolumab, pidilizumab, MEDI0680, atezolizumab, avelumab, durvalumab, MEDI6383, MEDI6469, RG7888, ipilimumab, tremelimumab, urelumab, PF-05082566, enoblituzumab, vantictumab, varlilumab, mogamulizumab, SAR650984, daratumumab, trastuzumab, trastuzumab emtansine, pertuzumab, elotuzumab, rituximab, ofatumumab, obinutuzumab, RG7155, FPA008, anti-HER2 antibody, anti-CD20 antibody, anti-CD19 antibody, anti-CS1 antibody, anti-CD38 antibody, panitumumab, or brentuximab vedotin.

22. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof has at least 80% sequence identity to any of SEQ ID NOs;

3-12 and 24-34.

23. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof is one of or a fragment of SEQ ID NOs;

13-23.

24. The construct of claim 1, wherein said SIRP-α

polypeptide or a fragment thereof comprises at least one amino acid substitution with a histidine residue.

25. The construct of claim 24, wherein said at least one amino acid substitution occurs at one or more of the following amino acid positions:

29, 30, 31, 32, 33, 34, 35, 52, 53, 54, 66, 67, 68, 69, 74, 93, 96, 97, 98, 100, 4, 6, 27, 36, 39, 47, 48, 49, 50, 57, 60, 72, 74, 76, 92, 94, 103, relative to a sequence of any one of SEQ ID NOs;

3-12.

26. The construct of claim 2, wherein said affinity is at least two, at least four, or at least six-fold higher.

27. The construct of claim 2, wherein said SIRP-α

polypeptide or a fragment thereof binds with at least two, at least four, or at least six-fold higher affinity to CD47 under hypoxic condition than under physiological condition.

28. The construct of claim 2, wherein said SIRP-α

polypeptide or a fragment thereof binds with at least two, at least four, or at least six-fold higher affinity to CD47 under acidic pH than under neutral pH.

29. A pharmaceutical composition comprising a therapeutically effective amount of the construct of claim 1.

30. A method of increasing phagocytosis of a target cell in a subject, comprising administering to said subject a construct according to claim 1.