Cosibelimab PD-L1 Delivers 50% ORR in Unresectable Locally Advanced cSCC

Cosibelimab is a high-affinity PD-L1 antibody evaluated at 800 mg IV every 2 weeks in the pivotal Phase 1 cutaneous SCC expansion cohort (NCT03212404). In unresectable locally advanced cSCC not amenable to curative surgery or radiation (n=64), investigator-assessed ORR was 50% with 17 CRs and 15 PRs at 31 months’ median follow-up, and median DOR was not reached. Grade ≥3 TEAEs occurred in 41%, treatment-related grade ≥3 events in 11%, and grade ≥3 immune-related AEs in 2%, broadly in the range of existing PD-1/PD-L1 options where cemiplimab and pembrolizumab have ORRs around the mid-30s to high-40s.