Extended follow-up of in vivo BCMA CAR-T therapy in relapsed/refractory multiple myeloma

Data on long-term outcomes of in vivo CAR-T therapy are scarce. A study at Huazhong University of Science and Technology (Wuhan, China) evaluated BCMA CAR-T (ESO-T01) in four patients with relapsed/refractory multiple myeloma without leukapheresis and lymphodepletion. With up to 3 months of follow-up, the objective reponse rate reached 100% (two stringent complete responses and two partial responses). All patients developed dual-phase CRS (grades 1-3) and hematotoxicities (grade ≥ 3). Long-term follow-up (up to 15 months) of the trial has now been reported. No immunogenicity- or integration-related toxicities occurred, and no important adverse events related to ESO-T01 emerged beyond the initial report. One of the four patients maintained stringent complete response for 15 months. Three patients experienced relapse or progression, all with extramedullary involvement, and eventually died during follow-up. The median progression-free survival was 4.0 months (range 3.0-15.0). After progression, diverse salvage therapies extended overall survival to 5.5-10.9 months after infusion. The authors conclude that the observed limited persistence necessitates further optimization of the in vivo CAR-T platform.