MRD-Guided BCMA/CD3 Bispecific Antibody Treatment After Stem Cell Transplant for Newly Diagnosed Multiple Myeloma

Inclusion criteria

• Be able to understand and voluntarily signs the informed consent form (ICF).
• Age ≥ 18 years.
• Newly diagnosed multiple myeloma according to the International Myeloma Working Group (IMWG) criteria.
• MRD positivity (≥10-⁵) detected by EuroFlow.
• Previous therapy limited to first-line treatment only, including: (1) Induction therapy with a 3- or 4-drug regimen containing a proteasome inhibitor and/or an immunomodulatory drug and/or an anti-CD38 monoclonal antibody; (2) Single or tandem autologous stem cell transplantation (ASCT); (3) Up to 2-4 cycles of consolidation therapy post-ASCT are permitted, with the total number of induction plus consolidation cycles not exceeding 8.
• Completion of ASCT within ≤12 months from the start of induction therapy; and ≤6 months from the most recent ASCT at enrollment (≤7 months if consolidation therapy was administered).
• No prior maintenance therapy.
• Achieved at least a partial response (≥PR) according to the IMWG 2016 response criteria.
• Presence of measurable disease at diagnosis.

Exclusion criteria

• Prior treatment with genetically modified adoptive cellular therapy.
• History of allogeneic stem cell transplantation or solid organ transplantation.
• Disease progression prior to enrollment (per IMWG 2016 response criteria), or presence of plasma cell leukemia, Waldenström macroglobulinemia, POEMS syndrome, or light-chain amyloidosis not attributable to symptomatic multiple myeloma.
• Central nervous system involvement.