Durable efficacy and manageable long-term safety of lisocabtagene maraleucel in 3L+ FL: 3-year update from TRANSCEND FL.

In the TRANSCEND FL primary analysis, lisocabtagene maraleucel (liso-cel) showed high response rates and favorable safety in patients with relapsed/refractory (R/R) follicular lymphoma (FL). Longer follow-up is needed to assess remission durability and long-term or late-onset toxicities. Here, we report 3-year follow-up results (median [range] on-study follow-up, 41.5 months [0.3‒54.0]) in patients with third-line or later (3L+) FL. Patients had R/R FL after ≥2 prior lines of combination systemic therapy, including an anti-CD20 antibody and an alkylator. A total of 107 patients received liso-cel and 103 were efficacy evaluable, with overall and complete response rates (95% CI) per independent review committee of 97% (92‒99) and 94% (88‒98), respectively. Medians were not reached for all time-to-event outcomes; estimated 36-month (95% CI) rates for duration of response, progression-free survival, time free from next treatment, and overall survival were 70% (60‒78), 68% (58‒76), 75% (70‒80), and 86% (78‒92), respectively. Response rates and 36-month time-to-event rates were consistent in high-risk subgroups, including patients with disease progression within 24 months of starting first-line immunochemotherapy, bulky disease, or double-refractory status. Longitudinal safety analyses showed decreasing grade ≥3 cytopenias and hypogammaglobulinemia (immunoglobulin G <500 mg/dL), with use of supportive care (transfusions, growth factors, intravenous immunoglobulin) mostly limited to the 3 months after infusion, and consistently low incidences of grade ≥3 infections in short- and long-term periods. At 3-year follow-up, a single liso-cel infusion delivered durable efficacy and high survival, including in high-risk subgroups, alongside a favorable long-term safety profile in patients with 3L+ FL. Clinicaltrials.gov: NCT04245839.