• Age greater than or equal to (\>=)18 years at the time of signing informed consent.

• Written informed consent in accordance with federal, local, and institutional guidelines.

• Measurable MM based on IMWG guidelines as defined by at least one of the following:

‣ Serum M-protein \>= 0.5 gram per deciliter (g/dL) by serum protein electrophoresis (SPEP) or, for Immunoglobulin (Ig) A myeloma, by quantitative IgA.

⁃ Urinary M-protein excretion \>= 200 mg/24 hours.

⁃ Free light chain (FLC) \>= 100 milligram per liter (mg/L), provided that the FLC ratio is abnormal.

• Only for arms Sd-40 BIW, Sd-100 QW and Sd-80 BIW prior to protocol version (PV) 5.0: Participants must have relapsed or refractory multiple myeloma (RRMM) and have previously received at least 4 anti-MM prior therapies and have MM that is refractory to previous treatment with at least 2 proteasome inhibitors (PIs), at least 2 immunomodulatory agent (IMiDs), and 1 anti-cluster of differentiation (CD38) monoclonal antibody. Refractory is defined as lesser than or equal to (\<=) 25 percent (%) response to therapy, or progression during therapy or progression within 60 days after completion of therapy.

• Only for Arms Sd-40 BIW and Sd-100 QW as of PV 5.0: Participants must have RR MM and have been previously treated with \>=3 anti-MM therapies (with exposure to at least 2 PI drugs, at least 2 IMiDs, and 1 anti-CD38 monoclonal antibody), and be refractory to at least 1 drug of each class (PI/IMiD/anti-CD38). Refractory is defined as \<=25% response to therapy or progression during therapy or progression within 60 days after completion of therapy.

• Only for arm SVd: Participants must have previously received 1 to 5 anti-MM prior therapies and have MM that is refractory to previous treatment with at least 1 PI, at least 1 IMiD, and 1 anti- CD38 monoclonal antibody.

• Eastern Cooperative Oncology Group (ECOG) performance status of \<= 2.

• Female participants of childbearing potential must agree to use dual methods of contraception and have a negative serum pregnancy test at screening, and male participants must use an effective barrier method of contraception if sexually active with a female of childbearing potential. For both male and female participants, effective methods of contraception must be used throughout the study and for 7 months for female and 4 months for male following the discontinuation of study treatment.