Antibody variable domains targeting the NKG2D receptor
Antibody heavy chain variable domains that can be paired with antibody light chain variable domains to form an antigen-binding site targeting the NKG2D receptor on natural killer cells are described. Proteins comprising an NKG2D antigen-binding site, pharmaceutical compositions and therapeutic methods thereof, including for the treatment of cancer, are also described.
1. An antigen-binding site that binds NKG2D, comprising an antibody heavy chain variable domain comprising a complementarity-determining region 1 (CDR1) sequence represented by the amino acid sequence of SEQ ID NO:48, a complementarity-determining region 2 (CDR2) sequence represented by the amino acid sequence of SEQ ID NO:30, and a complementarity-determining region 3 (CDR3) sequence represented by the amino acid sequence of SEQ ID NO:78, SEQ ID NO:74, SEQ ID NO:76, SEQ ID NO: 80, or SEQ ID NO:82; and an antibody light chain variable domain comprising
a CDR1 sequence identical to the amino acid sequence of SEQ ID NO:32, a CDR2 sequence identical to the amino acid sequence of SEQ ID NO:33, and a CDR3 sequence identical to the amino acid sequence of SEQ ID NO:34.
2. The antigen-binding site according to claim 1 , binding to NKG2D with a K D of 10-62 nM, as measured by surface plasmon resonance.
3. A protein comprising the antigen-binding site according to claim 1 and an additional antigen-binding site.
4. The protein according to claim 3 , wherein the additional antigen-binding site binds to a tumor-associated antigen.
5. The protein according to claim 4 , wherein the tumor-associated antigen is selected from the group consisting of HER2, EpCAM, CD2, CD20, CD30, CD38, CD40, CD52, CD70, EGFR/ERBB1, IGF1R, HER3/ERBB3, HER4/ERBB4, MUC1, SLAMF7, PSCA, MICA, MICB, TRAILR1, TRAILR2, MAGE-A3, B7.1, B7.2, CTLA4, and PD1.
6. The protein according to claim 3 , wherein the additional antigen-binding site comprises an antibody heavy chain variable domain; and
wherein the antibody heavy chain variable domain of the antigen-binding site that binds NKG2D is present on a first polypeptide further comprising a first antibody constant region, and the antibody heavy chain variable domain of the additional antigen-binding site is present on a second polypeptide further comprising a second antibody constant region.
7. The protein according to claim 6 , wherein the first antibody constant region and the second antibody constant region:
a. form a complex capable of binding CD16;
b. each comprise hinge, CH2, and CH3 domains;
c. each comprise CH1 hinge, CH2, and CH3 domains; and/or
d. are each at least 90% identical to human IgG1 constant region.
8. The protein according to claim 7 , wherein:
the amino acid sequence of the first antibody constant region differs from the amino acid sequence of an IgG1 constant region by a Y349C substitution and wherein the amino acid sequence of the second antibody constant region differs from the amino acid sequence of an IgG1 constant region by an S354C substitution; and/or
the amino acid sequence of the first antibody constant region differs from the amino acid sequence of an IgG1 constant region by K360E and K409W substitutions and wherein the amino acid sequence of the second antibody constant region differs from the amino acid sequence of an IgG1 constant region by Q347R, D399V and F405T substitutions.
9. The protein according to claim 3 , wherein the protein further comprises an antigen-binding site capable of binding CD16.
10. A formulation comprising the protein according to claim 3 and a pharmaceutically acceptable carrier.
11. The antigen-binding site according to claim 1 , wherein the CDR1, CDR2, and CDR3 sequences of the heavy chain variable domain are represented by the amino acid sequences of SEQ ID NOs: 48,30, and 78, respectively, and the CDR1, CDR2, and CDR3 sequences of the light chain variable domain are represented by the amino acid sequences of SEQ ID NOs: 32, 33, and 34, respectively.
12. The antigen-binding site according to claim 11 , wherein the antibody heavy chain variable domain comprises an amino acid sequence at least 95% identical to SEQ ID NO:85, and the antibody light chain variable domain comprises an amino acid sequence at least 95% identical to SEQ ID NO:8.
13. The antigen-binding site according to claim 1 , wherein the antibody heavy chain variable domain comprises the amino acid sequence of SEQ ID NO: 85, 83, 84, 86, or 41, and the antibody light chain variable domain comprises the amino acid sequence of SEQ ID NO:8.
14. The antigen-binding site according to claim 1 , wherein the antibody heavy chain variable domain comprises the amino acid sequence of SEQ ID NO:85, and the antibody light chain variable domain comprises the amino acid sequence of SEQ ID NO:8.