A Study of the Safety and Tolerability of ABBV-467 in Adult Participants With Relapsed/Refractory (R/R) Multiple Myeloma

Inclusion Criteria

• •Documented diagnosis of multiple myeloma (MM).
• •Measurable disease defined as at least 1 of the following:
• •* Serum monoclonal protein \>= 1g/dL.
• •* Urine M-protein \>= 200mg/24 hours.
• •* Serum immunoglobulin free light chain (FLC) \>= 10 mg/dL (100 mg/L), provided serum FLC ratio is abnormal.
• •Relapsed after or are refractory or intolerant to all established MM therapies that are both known to provide clinical benefit and locally available.
• •Received at least 3 prior lines of therapy including 1 or more immunomodulatory agents, 1 or more proteasome inhibitors, and 1 or more anti-CD38 monoclonal antibodies.
• •Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2.
• •Adequate hematologic, renal and hepatic function as described in the protocol.
• •Echocardiogram with ejection fraction \>= 50% and no other clinically significant findings that would increase the participant's susceptibility to cardiac toxicity.