CD38-binding proteins comprising de-immunized Shiga toxin A subunit effectors
The instant invention provides binding proteins (“CD38-binding proteins”) which each comprise (1) a CD38-binding region for cell-targeting and (2) a Shiga toxin A Subunit effector polypeptide (“Shiga toxin effector polypeptide”). The Shiga toxin effector polypeptide components of the CD38-binding proteins may comprise a combination of mutations relative to a wild-type Shiga toxin sequence providing (1) de-immunization and/or (2) a reduction in protease sensitivity; wherein each Shiga toxin effector polypeptide retains one or more Shiga toxin function, such as, e.g., stimulating cellular internalization, directing intracellular routing, catalytic activity, and/or potent cytotoxicity. The CD38-binding proteins may have one or multiple uses, e.g., the selective killing of a specific CD38-expressing cell-type; and more generally, for the diagnosis and treatment of cancers and disorders involving CD38-expressing cells, e.g., in CD38-positive hematopoietic cancers such as multiple myeloma.
1. A CD38-binding fusion protein comprising:
1) a Shiga toxin A subunit effector polypeptide; and
2) a CD38-binding domain, comprising:
a) a heavy chain variable domain (VH) comprising:
i) a vHCDR1 comprising the sequence of SEQ ID NO: 34;
ii) a vHCDR2 comprising the sequence of SEQ ID NO: 35; and
iii) a vHCDR3 comprising the sequence of SEQ ID NO: 36; and
b) a light chain variable domain (VL) comprising:
i) a vLCDR1 comprising the sequence of SEQ ID NO: 31;
ii) a vLCDR2 comprising the sequence of SEQ ID NO: 32; and
iii) a vLCDR3 comprising the sequence of SEQ ID NO: 33.
2. The CD38-binding fusion protein of claim 1 , wherein the CD38-binding fusion protein comprises the sequence of SEQ ID NO: 79.
3. The CD38-binding fusion protein of claim 1 , wherein the VL comprises the sequence of SEQ ID NO: 43, and the VH comprises the sequence of SEQ ID NO: 44.
4. The CD38-binding fusion protein of claim 1 , wherein the CD38-binding fusion protein comprises a first linker between the Shiga toxin A subunit effector polypeptide and the CD38-binding domain.
5. The CD38-binding fusion protein of claim 4 , wherein the first linker is a proteinaceous linker.
6. The CD38-binding fusion protein of claim 5 , wherein the first linker comprises the sequence of SEQ ID NO: 70.
7. The CD38-binding fusion protein of claim 4 , wherein the CD38-binding fusion protein comprises a second linker between the VH and the VL.
8. The CD38-binding fusion protein of claim 7 , wherein the CD38-binding fusion protein comprises, from its N- to C-terminus, the Shiga toxin A subunit effector polypeptide-first linker-VH-second linker-VL.
9. The CD38-binding fusion protein of claim 8 , wherein the Shiga toxin A subunit effector polypeptide comprises the sequence of SEQ ID NO: 46.
10. The CD38-binding fusion protein of claim 1 , wherein the Shiga toxin A subunit effector polypeptide comprises the sequence of SEQ ID NO: 46, the VL comprises the sequence of SEQ ID NO: 43, and the VH comprises the sequence of SEQ ID NO: 44.
11. The CD38-binding fusion protein of claim 1 , wherein the CD38-binding fusion protein is a homodimer.
12. The CD38-binding fusion protein of claim 1 , wherein the CD38-binding fusion protein comprises two identical polypeptides, each polypeptide comprising the sequence of SEQ ID NO: 79.
13. A nucleic acid encoding the CD38-binding protein fusion of claim 2 .
14. An expression vector comprising the nucleic acid of claim 13 .
15. A host cell comprising the expression vector of claim 14 .
16. A composition comprising (i) the CD38-binding fusion protein of claim 2 and (ii) a pharmaceutically acceptable carrier or excipient.
17. The composition of claim 16 , wherein at least about 90% of the CD38-binding fusion protein is in the form of a homodimer.
18. The composition of claim 17 , wherein at least about 95% of the CD38-binding fusion protein is in the form of a homodimer.