CD20-selective inhibition of CD47-SIRPα "don't eat me" signaling with a bispecific antibody-derivative enhances the anticancer activity of daratumumab, alemtuzumab and obinutuzumab.

ABSTRACT: Here, we report on a novel bispecific antibody-derivative, designated RTX-CD47, with unique capacity for CD20-directed inhibition of CD47-SIRPα "don't eat me" signaling. RTX-CD47 comprises a CD20-targeting scFv antibody fragment derived from rituximab fused in tandem to a CD47-blocking scFv. Single agent treatment with RTX-CD47 triggered significant phagocytic removal of CD20^pos/CD47^pos malignant B-cells, but not of CD20^neg/CD47^pos cells, and required no pro-phagocytic FcR-mediated signaling. Importantly, treatment with RTX-CD47 synergistically enhanced the phagocytic elimination of primary malignant B cells by autologous phagocytic effector cells as induced by therapeutic anticancer antibodies daratumumab (anti-CD38), alemtuzumab (anti-CD52) and

SUBMITTER: van Bommel PE 

PROVIDER: S-EPMC5749665 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature