A Study to Compare Iberdomide Maintenance Versus Lenalidomide Maintenance Therapy Following Autologous Stem Cell Transplant in Participants With Newly Diagnosed Multiple Myeloma

The purpose of this study is to compare the effectiveness of iberdomide maintenance to lenalidomide maintenance therapy after autologous stem cell transplantation (ASCT) in participants with newly diagnosed multiple myeloma (NDMM).

Inclusion Criteria * Confirmed diagnosis of symptomatic multiple myeloma (MM). * Eastern Cooperative Oncology Group performance status (ECOG) score of 0, 1, or 2. * Received 3 to 6 cycles of an induction therapy that includes a proteasome inhibitor (PI) and immunomodulatory (IMiD) \[eg, bortezomib thalidomide and dexamethasone (VTd), lenalidomide, bortezomib and dexamethasone (RVd)\] with or without a CD38 monoclonal antibody, daratumumab + bortezomib/thalidomide/dexamethasone \[D-VTd\] and daratumumab + bortezomib/ lenalidomide/dexamethasone \[D-VRd\]), or VCd / daratumumab + bortezomib/cyclophosphamide/dexamethasone \[D-VCd\], and followed by a single or tandem autologous stem cell transplantation (ASCT). Post-stem cell transplant consolidation is permitted. * Participants within 12 months (single transplant) or 15 months (tandem transplant) from initiation of induction therapy who achieved at least a partial response (PR) after autologous stem cell transplantation (ASCT) with or without consolidation, according to International Myeloma Working Group (IMWG 2016) criteria. Exclusion Criteria * Progressive disease or clinical relapse (as defined by IMWG response criteria) following ASCT with or without consolidation or is not responsive to primary therapy. * Smoldering myeloma, solitary plasmacytoma or nonsecretory myeloma. * Known central nervous system/meningeal involvement of MM. * Prior history of malignancies, other than MM, unless the participant has been free of the disease for ≥ 5 years. * Other protocol-defined Inclusion/Exclusion criteria apply.