Clinical Response of CD19 CAR-T Cells (relmacabtagene autoleucel, relma-cel) in Adults with Heavily-Pre-Treated Relapsed/Refractory (r/r) Large B-Cell Lymphoma in China

Currently, no CAR-T product has been approved for use in China despite having hundreds of active CAR-T trials. Relma-cel (JWCAR029) is a CAR-T product with a CAR construct comprised of a binding domain, derived from a murine CD19-specific mAb (FMC63), a CD3ζ activation domain, and a 4-1BB costimulatory domain, and manufactured in China with a commercial-ready, highly automated, single train process to select, activate, transduce and expand both CD4 and CD8 cells to a wide range of doses with consistent product attributes. Relma-cel was evaluated in the first prospective, single-arm, multi-center, pivotal study (RELIANCE Trial) of CAR-T therapy conducted under Chinese IND to support an NMPA-accepted BLA submission in r/r large B-cell lymphoma (LBCL) (NCT 04089215) and the preliminary results are presented herein. Eligible adult patients had measurable, histologically confirmed r/r LBCL, failed at least 2 prior therapies, including anthracycline and anti-CD20 agents, and not had allogeneic transplant within 90 days or primary CNS lymphoma. Patients were randomized to receive either 100×106 (low dose) or 150×106 (high dose) CAR+ T cells as a single infusion following fludarabine 25 mg/m2 & cyclophosphamide 250 mg/m2 daily×3 as lymphodepletion. Patients were evaluated for efficacy (Lugano criteria, 2014), safety (CRS by Lee 2014, and all other events by CTCAE v4.03), and PK (by qPCR and flow cytometry). The protocol pre-specified and regulatory authority-agreed primary endpoint was 3 month ORR by landmark analysis to exclude a 3-month 20% ORR (Michael, 2017). Secondary endpoints included best overall response rate (BOR), duration of response (DOR), progression free survival (PFS), overall survival (OS), frequency/severity of AEs and CAR-T cell expansion. Investigators adjudicated disease response and progression based on imaging studies, pathology and clinical data; a sensitivity analysis was also conducted using an independent review committee adjudication. Between May 2018 and Dec 2019, 69 patients were screened, and 59 enrolled and treated with relma-cel, with median age of 56.0 years (18-75), 59.3% ECOG 1-2, and included several LBCL subtypes (DLBCL NOS 69.5%, TFL 15.3%, DHL/THL 5.1%, and PMBCL 6.8%) and nearly all with poor risk disease (81.4% treatment refractory, 45.8% ≥3 lines of prior therapies, 42.4% requiring bridging therapy, 39% IPI≥3). The median doses administered in low and high dose groups were 99.7×106 (range, 80.1-101.3) and 150.0×106 (range