A Phase 1 Study of Vaccination With Dendritic Cell (DC)/Multiple Myeloma (MM) Fusions in Combination With Elranatamab in Relapsed or Refractory Multiple Myeloma

Inclusion Criteria for Tumor Collection: * Participants must have an established diagnosis of multiple myeloma * Participant must have multiple myeloma and have relapsed following or are refractory to proteasome inhibitors, IMiDs and anti-CD38 mAb therapy * Participants must have at least 3 prior lines of therapy * Participants must be ≥18 years of age * Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 * Participants must have \> 20% plasma cells in the bone marrow core or aspirate differential \<30 days prior to enrollment. * ANC \> 1K/uL; Platelets \> 50 K/uL without transfusional support * Participants must have adequate organ function as defined below: * Total bilirubin ≤1.5 x institutional upper limit of normal * AST ≤ 3 x institutional upper limit of normal * ALT ≤ 3 x institutional upper limit of normal * Creatinine clearance ≥ 40 mL/min for participants with creatinine levels above institutional normal * The effects of DC/MM fusion vaccine on the developing human fetus are unknown. For this reason, women and men of child-bearing potential must agree to use adequate contraception (hormonal or barrier methods of birth control or abstinence) prior to study enrollment and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner are participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adeq…