Incorporation of a Novel CD16-Specific Single-Domain Antibody into Multispecific Natural Killer Cell Engagers With Potent ADCC

• DOI: 10.1021/acs.molpharmaceut.1c00208
• Publication Date: 2021-05-17T19:29:21Z
• Authors: Henk van Faassen; Dong-Hyeon Jo; Shannon Ryan; Michael J. Lowden; Shalini Raphael; C. Roger MacKenzie; Seung-Hwan Lee; Greg Hussack; Kevin A. Henry
• Keywords: CD16; Single-domain antibody

Multispecific antibodies that bridge immune effector and tumor cells have shown promising preclinical clinical efficacies. Here, we isolated characterized novel llama single-domain (sdAbs) against CD16. One sdAb, NRC-sdAb048, bound recombinant human cynomolgus monkey CD16 ectodomains with equivalent affinity (KD: 1 nM) but did not recognize murine Binding was similar for CD16a expressed on NK CD16b (NA2) neutrophils dramatically weaker ∼6 μM) the (NA1) allotype. The sdAb stained primary peripheral blood cells. Irrespective of fusion orientation linker length, bispecific sdAb–sdAb sdAb–scFv dimers (anti-CD16/EGFR, anti-CD16/HER2, anti-CD16/CD19) retained full binding each target, coengaged both antigens simultaneously, elicited ADCC target antigen-expressing in a reporter bioassay, triggered target-specific activation degranulation as measured via interferon-γ CD107a expression. These molecules may applications cancer immunotherapy.