Enhanced CAR T-Cell Therapy for Lymphoma after Previous Failure

Abstract

Background: Chimeric antigen receptor (CAR) T cells targeting CD19 have transformed the treatment of B-cell cancers, but many patients do not have long-term remission. We designed an anti-CD19 enhanced (armored) CAR T-cell product (huCART19-IL18) that secretes interleukin-18 to enhance antitumor activity.

Methods: In this study, we assessed the safety, feasibility, and preliminary efficacy of huCART19-IL18 in patients with relapsed or refractory lymphoma after previous anti-CD19 CAR T-cell therapy. Using a 3-day manufacturing process, we administered huCART19-IL18-positive cells in doses ranging from 3×10⁶ to 3×10⁸.

Results: A total of 21 patients received huCART19-IL18. Cytokine release syndrome occurred in 62% of the patients (47% with grade 1 or 2), and immune effector-cell-associated neurotoxicity syndrome occurred in 14% (all grade 1 or 2). No unexpected adverse events were observed. Robust CAR T-cell expansion was detected across all dose levels. At 3 months after infusion, a complete or partial response was seen in 81% of the patients (90% confidence interval [CI], 62 to 93) and a complete response in 52% (90% CI, 33 to 71). With a median follow-up of 17.5 months (range, 3 to 34), the median duration of response was 9.6 months (90% CI, 5.5 to not reached).

Conclusions: In this small study, huCART19-IL18 had a safety profile consistent with other CAR T-cell treatments and showed promising efficacy at low cell doses in patients with lymphoma after the failure of previous anti-CD19 CAR T-cell therapy. (ClinicalTrials.gov number, NCT04684563.).