A Phase 1, Multicenter, Open-label Study to Evaluate the Safety and Preliminary Efficacy of BMS-986393 in Novel Combinations in Participants with Relapsed and/or Refractory Multiple Myeloma and Determine the Recommended Dose for Each Add-on Investigational Component (Phase I GPRC5D Combo)

The purpose of this study is to establish a safe and tolerable dose of arlocabtagene
autoleucel (BMS-986393) in combinations with alnuctamab, mezigdomide, iberdomide, and
elranatamab in participants with relapsed and/or refractory multiple myeloma (RRMM).

Inclusion Criteria:

- History of relapsed and/or refractory multiple myeloma (RRMM) treated with at least
3 (Part 1), history of RRMM or at least 1 but not greater than 3 prior anti-myeloma
treatment (PAMT) regimens (Part 2, Arms A, B, C, and D); history of quadruple class
exposed RRMM having received BCMA TCE as the most recent line of therapy (Part 2,
Arm E).

- Measurable multiple myeloma (MM) as per International Myeloma Working Group (IMWG).

- Eastern Cooperative Oncology Group performance status of 0-1.

- Adherence to contraception requirements.

Exclusion Criteria:

- Prior treatment with alnuctamab (Arm A), mezigdomide (Arms B and E), iberdomide (Arm
C), elranatamab (Arm D) or BCMA-targeting therapy (Part 2 Arms A and D).

- Prior treatment with GPRC5D-targeting therapies as of Protocol Amendment 02 (Part 1
and Part 2).

- Other protocol-defined inclusion/exclusion criteria apply.