A PHASE 1, MULTICENTER, OPEN-LABEL STUDY OF CC-95266 IN SUBJECTS WITH RELAPSED AND/OR REFRACTORY MULTIPLE MYELOMA

The purpose of this study is to evaluate the safety and preliminary efficacy of CC-95266
in participants with relapsed and/or refractory multiple myeloma (R/R MM).

Inclusion Criteria:

- Age ≥ 18 years

- Participant has a diagnosis of multiple myeloma (MM) with relapsed and/or refractory
disease. Participants must have confirmed progressive disease (as per IMWG criteria)
on or within 12 months of completing treatment with the last anti-myeloma treatment
regimen before study entry or have confirmed progressive disease within 6 months
prior to screening and who are subsequently determined to be refractory or
non-responsive to their most recent anti-myeloma treatment regimen, except for
participants with cellular therapy (e.g., Chimeric antigen receptor (CAR) T-cell
therapy) as their last treatment, who may enroll beyond 12 months.

- Participants in Part A, and Part B Cohort A, and Part B Cohort B must have received
at least 3 prior anti-myeloma treatment regimens (note: induction with or without
hematopoietic stem cell transplant (HSCT) and with or without maintenance therapy is
considered one regimen).Subjects in Part B Cohort C only must have received at least
1 but not greater than 3 prior anti-myeloma treatment regimens, including a
proteasome inhibitor and immunomodulatory agent including:

- Autologous HSCT, unless the subject was ineligible

- A regimen that included an immunomodulatory agent (e.g., thalidomide,
lenalidomide, pomalidomide) and a proteasome inhibitor (e.g., bortezomib,
carfilzomib, ixazomib), either alone or combination

- Anti-CD38 (e.g., daratumumab), either alone or combination. Subjects in Cohort
C do not require prior anti-CD38 antibody therapy.

- Measurable disease

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

- Adequate organ function

Exclusion Criteria:

- Known active or history of central nervous system (CNS) involvement of MM

- Active or history of plasma cell leukemia, Waldenstrom's macroglobulinemia, POEMS
(polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes)
syndrome, or clinically significant amyloidosis

- Active autoimmune disease requiring immunosuppressive therapy

- History or presence of clinically significant CNS pathology such as seizure
disorder, aphasia, stroke, severe brain injuries, dementia, Parkinson's disease,
cerebellar disease, or psychosis

Other protocol-defined inclusion/exclusion criteria apply.