- Documented diagnosis of multiple myeloma (MM) based on standard IMWG criteria.
- Measurable disease at screening as defined per protocol.
- Has received at least 2 prior lines of therapy as described in the protocol.
- Has had documented disease progression on or within 60 days after completion of the last therapy.
- Has received at least 2 consecutive cycles of lenalidomide and be relapsed/refractory to lenalidomide, as defined per protocol.
- Has received at least 2 consecutive cycles of a proteasome inhibitor (PI).
- Has MM positive for t(11;14).
- An Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2.
- Laboratory values (liver, kidney and hematology laboratory values) that meet criteria as described per protocol.
- History of treatment with venetoclax or another B-Cell Lymphoma (BCL)-2 inhibitor or pomalidomide.
- History of other active malignancies, including myelodysplastic syndromes (MDS), within the past 3 years (exceptions described in the protocol).
- Evidence of ongoing graft-versus-host disease (GvHD) if prior stem cell transplant (SCT).
- Prior treatment with any of the following: allogeneic or syngeneic SCT within 16 weeks prior to randomization; or autologous SCT within 12 weeks prior to randomization.
- Known central nervous system involvement of MM.
- Concurrent conditions as listed in the protocol.