A Study Evaluating Safety, Tolerability, and Clinical Activity of Forimtamig-Based Treatment Combinations in Participants With Relapsed or Refractory Multiple Myeloma

Exclusion Criteria

• •Pregnant or breastfeeding or intending to become pregnant during the study or within 3 months after the last dose of study drug
• •Plasma cell leukemia with circulating plasma cell count ≥ 5% or \>500/microliter (µL)
• •Participants with known amyloidosis
• •Participants with myelodysplastic syndrome
• •Prior treatment with monoclonal antibody (mAb) and antibody-drug conjugate within 4 weeks or 5 half-lives of the drug, whichever is shorter
• •Prior anti-cancer therapy (chemotherapy, small molecule/tyrosine kinase inhibitors, radiotherapy) within 14 days prior to first forimtamig administration
• •Prior solid organ transplantation
• •Active auto-immune disease or flare within 6 months prior to start of study treatment
• •Known or suspected chronic active Epstein-Barr virus (EBV) infection
• •Hepatitis B virus (HBV) infection
• •Acute or chronic hepatitis C virus (HCV) infection
• •Known history of HIV seropositivity
• •Live vaccine(s) within one month prior to start of the treatment
• •Participants not fully vaccinated for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as per local recommendations
• •Previous refractoriness to carfilzomib
• •Participants who discontinued prior carfilzomib treatment due to treatment-related toxicity
• •Participants with known liver cirrhosis
• •Participants eligible for allogeneic stem cell transplantation (SCT) or autologous SCT at the time of enrollment for Study BP43437 are excluded