[Role of CAR-T in multiple myeloma and coordination between referring and treating centers]

Immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and anti-CD38 antibodies have been the three mainstays of myeloma treatment. B-cell maturation antigen (BCMA)-targeted immunotherapy, including chimeric antigen receptor T-cell therapy (CAR-T) and bispecific antibodies (BsAbs), is emerging as another important class of treatment. Two BCMA-targeting CAR-T products, idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel, are approved in Japan, but only ide-cel is available for clinical use. Recently, a randomized phase III study comparing ide-cel with standard therapy in patients with refractory myeloma who had received 2 to 4 prior lines of therapy showed that ide-cel was superior in terms of both response rate and PFS. Based on these results, ide-cel was approved as a third-line therapy. The new availability of bispecific antibodies has also raised new clinical questions regarding how to use CAR-T and BsAbs for each patient, and in what order. Limited data have suggested that favorable responses can be achieved when BsAbs are administered after CAR-T, but responses are suboptimal when CAR-T is administered after BsAbs. Finally, it is important to note that coordination between referring centers and treating centers, including aspects such as timing of patient referral, bridging therapy, and long-term follow-up after CAR-T, is critical to optimization of CAR-T.