• Participant must be 18 years of age inclusive or older.

• Eastern Cooperative Oncology Group (ECOG) performance status 0-1.

• Participants with relapsed or refractory MM who have received at least 2 prior lines of therapy for MM, including PIs and IMiDs (eg, Induction regimen with autologous stem cell transplant followed by maintenance is considered one line).

• RRMM with measurable disease:

‣ Serum M protein ≥0.5 g/dL measured using serum protein immunoelectrophoresis and/or

⁃ Urine M protein ≥200 mg/24 hours measured using urine protein immunoelectrophoresis and/or

⁃ Serum free light chain (sFLC) MM without measurable M protein in serum or urine per previous criteria (serum Ig free light chain ≥10 mg/dL and abnormal serum Ig kappa lambda free light chain ratio \<0.26 or \>1.65).

• Men or woman or childbearing potential should agree to use contraception.

• Substudy 01, 06: Anti-CD38 therapy naïve or prior exposure to such drugs with a wash out of at least 12 months after the last dose. Exposure is defined as at least 2 cycles of therapy.

• Substudies 02, 03: Anti-CD38 therapy naïve or prior exposure to such drugs without being refractory but with a wash out of at least 6 months after the last dose. Refractory is defined as progressing within 60 days of last dose of anti-CD38 targeting therapy.

• Substudy 04: Anti-CD38 and anti-B cell maturation antigen (BCMA) therapy (if available) prior exposed participants with RRMM. For anti-CD38, Exposure is defined as at least 2 cycles of therapy. For anti-BCMA therapy if available, exposure is defined by at least 2 cycles of therapy.

• Substudy 05: Participants with RRMM with at least 2 cycles of prior exposure to anti-CD38 therapy. For participants to whom BCMA targeted therapy is available (ie, approved in their region and can be reimbursed), at least 2 cycles of prior exposure to a BCMA targeted agent is mandatory.