Inclusion Criteria:  Diagnosis of relapsed/refractory (R/R) multiple myeloma (MM) with documented evidence of progression during or after the participant's last treatment regimen based on the investigator's determination of the International Myeloma Working Group (IMWG) criteria.  Relapsed defined as previously treated myeloma that progresses and requires initiation of salvage therapy, but does not meet criteria for refractory myeloma. Refractory defined as disease that is nonresponsive (failure to achieve minimal response or development of progressive disease) while on primary or salvage therapy, or progresses within 60 days of last therapy. Measurable disease per the protocol within 28 days prior to enrollment.  Arm A - Lemzoparlimab with or without Dexamethasone  For Both Escalation and Expansion Phase, participant must have refractory to 3 prior lines of treatment of anti-myeloma treatments, as outlined in the protocol.  Arm B - Lemzoparlimab + Pomalidomide-Dexamethasone  For Escalation Phase - Participant must have received at least 3 prior lines of therapy, as outlined in the protocol. For Expansion Phase- Participant must have received at least 2 prior line of therapy, as outlined in the protocol.  Arm C - Lemzoparlimab + Carfilzomib-Dexamethasone  For Escalation Phase- Participant must have received at least 3 prior lines of therapy as outlined in the protocol. For Expansion Phase- Participant must have received at least 1 prior line of therapy. Arm D - Lemzoparlimab + Daratumumab-Dexamethasone -- For Both Escalation and Expansion Phase - Participant must: --- Have received at least 3 prior lines of therapy, as outlined in the protocol.  Exclusion Criteria:  Arm B - Lemzoparlimab + Pomalidomide-Dexamethasone  For Both Escalation and Expansion Phase participant must have had no prior treatment with pomalidomide.  Arm C - Lemzoparlimab + Carfilzomib-Dexamethasone  For Both Escalation and Expansion Phase - prior treatment with carfilzomib.  Arm D - Lemzoparlimab + Daratumumab-Dexamethasone  For Both Escalation and Expansion Phase - prior treatment with daratumumab or other anti-CD38 therapy.