Inclusion Criteria:

        Participants must satisfy the following criteria to be enrolled in the study:

          1. must understand and voluntarily sign an informed consent form (ICF) prior to any
             study-related assessments/procedures being conducted.

          2. willing and able to adhere to the study visit schedule and other protocol
             requirements.

          3. Participant is ≥ 18 years of age the time of signing the ICF.

          4. Participant has a history of multiple myeloma (MM) with relapsed and/or refractory
             disease who have failed or who are ineligible or intolerant to available therapies
             that may provide clinical benefit.

          5. Have documented disease progression on or within 12 months from the last dose of their
             last myeloma therapy.

          6. Participant must have measurable disease.

          7. Participant has an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of
             0 or 1.

          8. Females of childbearing potential (FCBP) must commit to true abstinence from
             heterosexual contact or agree to use at least one method of highly effective
             contraception without interruption from screening to at least 9 weeks after the last
             dose of CC-92328

          9. Males must practice true abstinence or agree to use a condom

         10. FCBP and males must avoid conceiving from signing the ICF, while participating in the
             study, during dose interruptions, and for at least 9 weeks after the last dose of
             CC-92328.

        Exclusion Criteria:

        The presence of any of the following will exclude a participant from enrollment:

          1. Participant has symptomatic central nervous system involvement of MM.

          2. Participant had a prior autologous stem cell transplant ≤ 90 days prior to starting
             CC-92328.

          3. Participant had a prior allogeneic stem cell transplant with either standard or
             reduced intensity conditioning ≤ 12 months prior to starting CC-92328.

          4. Participant had prior systemic cancer-directed treatments or investigational
             modalities ≤ 5 half-lives or 4 weeks prior to starting CC-92328, whichever is shorter.

          5. Participant is a pregnant or lactating female.

          6. Participant received live virus vaccines within at least 4 weeks prior to starting
             study drug.

          7. Participant has known active human immunodeficiency virus (HIV) infection.

          8. Participant has active hepatitis B or C (HBV/HCV) infection.

          9. Participant weight is ≤ 40 kg at screening.