PD-L1 analog fusion proteins for antigen specific immunotherapy and methods of use
The present disclosure provides recombinantly manufactured fusion proteins comprising a Programmed Death-Ligand 1 (PD-L1) protein fragment or an analog thereof linked to a canine Fc fragment. Embodiments include the administration of the fusion proteins to patients as a treatment for cancers, tumors or other diseases associated with expression of the PD-L1 protein in dogs. Exemplary Fc fusion proteins and pharmaceutical formulations of exemplary Fc fusion proteins are provided, in addition to methods of use and preparation.
1. A fusion protein comprising a PD-L1 analog and an Fc fragment, wherein the PD-L1 analog and the Fc fragment are connected by a peptide linker, wherein the PD-L1 analog consists of the sequence:
(SEQ ID NO: 23)
LIGYGGADYKRITLKVHAPYRNISQRISVDPVTSEHELMCQAEGYPEAE
VIWTSSDHRVLSGKTTITNSNREEKLFNVTSTLNINATANEIFYCTFQR
SGPEENNTAELVIPERLPVPASERTHFMILGPF,
and
wherein the Fc fragment comprises the sequence:
(SEQ ID NO: 1)
DCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEV
QISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCK
VNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSLTCLIKD
FFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQ
RGDTFICAVMHEALHNHYTQESLSHSPG.
2. The fusion protein of claim 1 , wherein the PD-L1 analog and the Fc fragment are connected by the peptide linker comprising the sequence:
(SEQ ID NO: 6)
GGGGQGGGSGGQGGGGG.
3. A fusion protein comprising a PD-L1 analog consisting of SEQ ID NO: 23 and an Fc fragment, wherein the PD-L1 analog and the Fc fragment are connected by a peptide linker, wherein the fusion protein comprises the sequence:
(SEQ ID NO: 24)
LIGYGGADYKRITLKVHAPYRNISQRISVDPVTSEHELMCQAEGYPEAE
VIWTSSDHRVLSGKTTITNSNREEKLFNVTSTLNINATANEIFYCTFQR
SGPEENNTAELVIPERLPVPASERTHFMILGPFGGGGQGGGSGGQGGGG
GDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPE
VQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
KVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSLTCLIK
DFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRW
QRGDTFICAVMHEALHNHYTQESLSHSPG.
4. The fusion protein of claim 1 , wherein the fusion protein is a homodimer comprising two identical monomers bound together via one or more disulfide bonds.
5. The fusion protein of claim 1 , wherein the Fc fragment is glycosylated.
6. An immunogenic composition comprising a fusion protein according to claim 1 and a pharmaceutically acceptable carrier.
7. The immunogenic composition of claim 6 , further comprising an adjuvant.
8. A fusion protein comprising the sequence of SEQ ID NO: 24 or pharmaceutical composition thereof for use in treatment for cancers or tumors in dogs.
9. A treatment method comprising administering via injection the fusion protein or pharmaceutical composition of claim 8 to a dog in need thereof, wherein duration of response to dose levels varying from 1 μg to 100 μg of the fusion protein demonstrates increased anti-PD-L1 protein antibody titers at all dose levels after 1, 2, and 3 doses up to at least 56 days post injection.
10. The method of claim 9 , wherein said fusion protein or pharmaceutical composition thereof is administered subcutaneously or intramuscularly.
11. A method of treating cancers or tumors in a dog, the method comprising administering a fusion protein according to claim 1 or pharmaceutical composition thereof to a dog in need thereof.
12. The method of claim 11 , wherein said fusion protein or pharmaceutical composition thereof is administered via injection.
13. The method of claim 12 , wherein said fusion protein or pharmaceutical composition thereof is administered subcutaneously or intramuscularly.
14. The method of claim 11 , wherein said fusion protein or pharmaceutical composition thereof is administered as a priming vaccine, the method further comprising administering a booster of said fusion protein or pharmaceutical composition thereof 7 to 14 days after administering said priming vaccine.
15. The method of claim 11 , wherein said dog is antibody-positive to PD-L1 before said administering step, wherein said fusion protein or pharmaceutical composition thereof is administered as a booster vaccine to said dog.
16. A method of treating cancers or tumors in a dog, the method comprising administering a fusion protein according to claim 3 or pharmaceutical composition thereof to a dog in need thereof.
17. The method of claim 16 , wherein said fusion protein or pharmaceutical composition thereof is administered via injection.
18. The method of claim 17 , wherein said fusion protein or pharmaceutical composition thereof is administered subcutaneously or intramuscularly.
19. The method of claim 16 , wherein said fusion protein or pharmaceutical composition thereof is administered as a priming vaccine, the method further comprising administering a booster of said fusion protein or pharmaceutical composition thereof 7 to 14 days after administering said priming vaccine.
20. The method of claim 16 , wherein said dog is antibody-positive to PD-L1 before said administering step, wherein said fusion protein or pharmaceutical composition thereof is administered as a booster vaccine to said dog.