A Study to Evaluate Efficacy and Safety of Alnuctamab Compared to Standard of Care Regimens in Participants With Relapsed or Refractory Multiple Myeloma (RRMM)

Inclusion Criteria

* Participant is willing and able to adhere to the study visit schedule and other protocol requirements including bone marrow aspirations and/or biopsies and hospitalization during the first cycle.
* Documented diagnosis of multiple myeloma (MM), and must:.

  i) Received at least 1 but not more than 3 prior lines of anti-myeloma therapy.

ii) Received prior treatment with lenalidomide and an anti-CD38 monoclonal antibody (for at least 2 consecutive cycles).

iii) Achieved minimal response (MR) or better to at least 1 prior anti-myeloma therapy.

iv) Documented PD during or after their last anti-myeloma therapy or failure to achieve response.

* Must have measurable disease (as determined by central laboratory).
* Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, 1, or 2 at the time of the screening.

Exclusion Criteria

* Active, uncontrolled, or suspected infection.
* Known current, or history of, central nervous system involvement of multiple myeloma.
* History or presence of clinically relevant CNS pathology.
* Received prior BCMA-targeted TCE or BCMA-targeted CAR-T therapy.
* Previously received allogeneic stem cell transplantation at any time or received autologous stem cell transplantation within 3 months of initiating study intervention.
* Other protocol-defined Inclusion/Exclusion criteria apply.