Measurable Residual Disease-Guided Post-Transplant Elranatamab Maintenance

Criteria for Pre-Screening Blood Draw * Newly diagnosed multiple myeloma (either untreated or receiving first line therapy). * Potentially eligible for autologous hematopoietic cell transplant (with or without tandem transplant) for frontline therapy. Inclusion Criteria: * At least 18 years of age * Ability to understand and willingness to sign an IRB approved written informed consent document. (Legally authorized representatives may sign and give informed consent on behalf of study participants.) * Received autologous hematopoietic cell transplantation (with or without tandem transplant) as part of frontline therapy for newly diagnosed IgG or IgA multiple myeloma. Frontline therapy in this setting is defined as treatment received prior to first relapse and may include multiple lines of therapy per the Rajkumar et al definition if treatment changes were made for either toxicity or inadequate response to initial induction. * Received frontline treatment with at least a triplet regimen including a PI and an IMID (+/- an anti-CD38 antibody) * Disease response of ≥ partial response (PR) by IMWG criteria at time of study screening (post-transplant). * MRD-positive on Day 100 landmark assessment (80 to 160 days after AHCT), defined as \>1 x 10-5 myeloma cells/cell by clonoSEQ assay (Adaptive Biotechnologies, Seattle, WA) performed on bone marrow aspirate. * ECOG performance status ≤ 2 * All toxicities from prior treatment should have resolved to Grade ≤ 1 prior to enrollment. * …