Procedures
toxicities, DLTs
ADVERSE EVENTS, DISEASE PROGRESSION
The Phase 1 portion of the study enrolled 3 eligible patients to receive the approved dose of isatuximab 10 mg/kg intravenously (IV) once weekly for 4 weeks followed by 10 mg/kg once every 2 weeks and cemiplimab 250 mg IV once every 2 weeks (Isa + CemiQ2W). In the case of dose‐limiting toxicities (DLTs), dose de‐escalation (Table Phase 1 treatment dose and schedule.Abbreviations: QW, weekly; Q2W, every 2 weeks; Q4W, every 4 weeks.The Phase 2 portion of the study randomly assigned eligible patients to one of three treatment arms in a 1:1:1 ratio using Interactive Response Technology. Patients in arm 1 (the control arm; Isa) received isatuximab 10 mg/kg once weekly for 4 weeks followed by once every 2 weeks. Patients in arm 2 received isatuximab 10 mg/kg once weekly for 4 weeks followed by once every 2 weeks plus cemiplimab 250 mg once every 2 weeks (Isa + CemiQ2W). Patients in arm 3 received Isa 10 mg/kg once weekly for 4 weeks followed by once every 2 weeks plus cemiplimab 250 mg once every 4 weeks (Isa + CemiQ4W). Alternative Phase 2 study designs were in place should DLTs during Phase 1 have changed the predicted Phase 2 treatment doses and schedules. All cycles were 28 days in length. Premedication with acetaminophen (650–1000 mg orally), ranitidine (50 mg IV), diphenhydramine (25–50 mg IV), and methylprednisolone (100 mg IV) was administered 30–60 minutes prior to isatuximab infusion. In both phases of the study, patients continued treatment until disease progression, unacceptable adverse events (AEs), consent withdrawal, or any other reason.