C-kit binding proteins, chimeric antigen receptors, and uses thereof

A single domain antibody which specifically binds to c-Kit, wherein the single domain antibody comprises a heavy chain variable (VH) region comprising:

• (a) (i) a VH complementarity determining region one (CDR1) comprising a sequence having at most two amino acid modifications relative to SEQ ID NO:
• 1, SEQ ID NO:
• 2, or SEQ ID NO:
• 3;
• (ii) a VH CDR2 comprising a sequence having at most two amino acid modifications relative to SEQ ID NO:
• 4, SEQ ID NO:
• 5, SEQ ID NO:
• 6, or SEQ ID NO:
• 7;
• and
• (iii) a VH CDR3 comprising a sequence having at most two amino acid modifications relative to SEQ ID NO:
• 8, SEQ ID NO:
• 9, or SEQ ID NO:
• 10;
• or
• (b) a VH CDR1 comprising a sequence having at most two amino acid modifications relative to SEQ ID NO:
• 11;
• a VH CDR2 comprising a sequence having at most two amino acid modifications relative to SEQ ID NO:
• 12;
• and a VH CDR3 comprising a sequence having at most two amino acid modifications relative to SEQ ID NO:
• 13.

A single domain antibody which specifically binds to c-Kit, wherein the single domain antibody comprises a heavy chain variable (VH) region comprising:

• (i) a VH complementarity determining region one (CDR1) comprising the sequence
• (SEQ ID NO:
• 53)
• G X1 T X2 X3 X4 Y A,
• wherein X1 is F or L;
• X2 is F or I;
• X3 is D or S;
• and X4 is S or T;
• (ii) a VH CDR2 comprising the sequence
• (SEQ ID NO:
• 71)
• I S X5 X6 G X7 X8 T,
• wherein X5 is V or T, X6 is R or G;
• X7 is G or S;
• and X8 is S or R;
• and
• (iii) a VH CDR3 comprising the sequence
• (SEQ ID NO:
• 54)
• A T G Y D X9 S G X10 Y Y G G F D Y,
• wherein X9 is S or P;
• and X10 is Y or H.

A single domain antibody which specifically binds to c-Kit, wherein the single domain antibody comprises a heavy chain variable (VH) region comprising:

• (i) a VH complementarity determining region one (CDR1) comprising a sequence chosen from SEQ ID NO:
• 1, SEQ ID NO:
• 2, and SEQ ID NO:
• 3;
• (ii) a VH CDR2 comprising a sequence chosen from SEQ ID NO:
• 4, SEQ ID NO:
• 5, SEQ ID NO:
• 6, and SEQ ID NO:
• 7;
• and
• (iii) a VH CDR3 comprising a sequence chosen from SEQ ID NO:
• 8, SEQ ID NO:
• 9, and SEQ ID NO:
• 10.

A single domain antibody which specifically binds to c-Kit, wherein the single domain antibody comprises a heavy chain variable (VH) region comprising:

• (a) a VH CDR1, a VH CDR2, and a VH CDR3 comprising the sequences of SEQ ID NOs:
• 1, 4, and 8, respectively;
• (b) a VH CDR1, a VH CDR2, and a VH CDR3 comprising the sequences of SEQ ID NOs:
• 2, 5, and 9, respectively;
• (c) a VH CDR1, a VH CDR2, and a VH CDR3 comprising the sequences of SEQ ID NOs:
• 3, 6, and 8, respectively;
• (d) a VH CDR1, a VH CDR2, and a VH CDR3 comprising the sequences of SEQ ID NOs:
• 2, 7, and 10, respectively;
• or
• (e) a VH CDR1, a VH CDR2, and a VH CDR3 comprising the sequences of SEQ ID NOs:
• 11, 12, and 13, respectively.