Relmacabtagene autoleucel (relma-cel) CD19 CAR-T therapy for adults with heavily pretreated relapsed/refractory large B-cell lymphoma in China.

Background: Despite numerous chimeric antigen receptor T-cell (CAR-T) trials conducted in China, no CAR-T has been registered in the country. Furthermore, China law and regulations restrict the export of patient material for CAR-T manufacture abroad. Relma-cel (JWCAR029), an anti-CD19 product produced with a commercial-ready process in China, was evaluated in the first prospective, single-arm, multicenter, pivotal study of CAR-T therapy conducted under Chinese IND to support an NMPA-accepted BLA submission in relapsed/refractory (r/r) LBCL (NCT04089215).

Methods: Patients were randomized to receive either 100 × 10 (low dose, n = 27) or 150 × 10 (high dose, n = 32) CAR+ T-cells as a single infusion following lymphodepleting chemotherapy (fludarabine 25 mg/m and cyclophosphamide 250 mg/m daily × 3), and then, monitored for efficacy and safety outcomes and pharmacokinetics. The primary endpoint was ORR at 3 months, as assessed by the investigators. Secondary endpoints included DOR, PFS, OS, and adverse event frequency/severity and cell expansion kinetics.

Results: As of the data cutoff on 17 June 2020, 68 patients were enrolled, and 59 were treated. Among the 58 efficacy-evaluable patients, the primary endpoint of 3 month ORR was 60.3% (95% CI, 46.6-73.0), excluding the null hypothesis rate of 20%. Any grade and severe grade CRS occurred in 47.5% and 5.1%, respectively, and any grade and severe grade neurotoxicity events occurred in 20.3% and 5.1%.

Conclusions: Relma-cel met the primary endpoint analysis and demonstrated a high rate of durable responses and low rate of CAR-T-associated toxicities in patients with r/r LBCL in a multicenter trial supporting regulatory submission in China.