MRD-Adaptive Guided Immunotherapy With CAR-T for Transplant-Ineligible Patients With Multiple Myeloma

Enrolled patients will be stratified into standard-risk group based on the absence of ultra-high-risk features, defined as: (1) double-hit cytogenetics, (2) presence of extramedullary disease, or (3) circulating tumor cells (CTCs) ≥2%. Patients in the standard-risk group will receive BCMA CAR-T therapy after standard induction, followed by standard consolidation and maintenance. Patients achieving sustained MRD negativity and stringent complete response (sCR) on two consecutive assessments may enter a treatment-free observation phase. Patients who experience MRD resurgence or loss of response will resume maintenance therapy.

Enrolled patients will be stratified into an ultra-high-risk group based on the presence of ultra-high-risk features, defined as: (1) double-hit cytogenetics, (2) presence of extramedullary disease, or (3) circulating tumor cells (CTCs) ≥2%. Patients in the ultra-high-risk group will also receive BCMA CAR-T therapy after induction, followed by GPRC5D/CD3 bispecific antibody consolidation and maintenance. Patients achieving sCR and sustained MRD negativity (≥12 months) may enter treatment-free observation, while those with MRD resurgence or loss of response will resume maintenance therapy.