B07 | LONG-TERM CLINICAL OUTCOMES WITH TISAGENLECLEUCEL IN HIGH-RISK RELAPSED/REFRACTORY FOLLICULAR LYMPHOMA: 4-YEAR FOLLOW-UP FROM THE PHASE 2 ELARA STUDY

Background: Treatment approach for relapsed/refractory follicular lymphoma (r/r FL) depends on previous treatments and patients’ characteristics. Tisagenlecleucel is a Chimeric Antigen Receptor T-cell therapy (CAR-T) approved for adults with r/r FL after at least two prior lines of systemic therapy. We present 4-year follow-up results on efficacy, safety, and pharmacokinetics of tisagenlecleucel treatment from phase 2 ELARA trial [1]. Methods: Patients with r/r FL (grades 1–3A), who had received at least two prior systemic therapies (including an anti-CD20 monoclonal antibody and alkylating agent), were treated with a single infusion of tisagenlecleucel (0.6–6×10⁸ CAR-positive viable T cells). Bridging therapy was allowed. Progression-free survival (PFS) and overall survival (OS) were correlated to baseline clinical characteristics and levels of circulating naïve T cells. Results: By March 27, 2024, 97 patients had received treatment, and 94 were evaluated for efficacy, with a median follow-up of 53 months (range: 46–62 months). At baseline, high-risk subgroups were identified: 66.0% had bulky disease and 64.9% experienced disease progression within two years of initial therapy (POD24). A high Follicular Lymphoma International Prognostic Index (FLIPI ≥3) was observed in 60.6% of patients, while 21.3% had a high tumor burden. The median PFS across all patients was 53.3 months (95% CI: 18.2–not estimable). At 48 months, the PFS was 50.2% in the overall population and 66.1% in patients who achieved the best overall response. In high-risk subgroups, 48-month PFS was 45.5% in POD24 group, 45.5% for high FLIPI, 45.2% in participants with bulky disease and 52.8% for double refractory. At 48 months, the OS rate among efficacy-evaluable patients was 79.3%; while the median OS was not reached. The 48-month OS rates were 80.8% for POD24, 73.2% for those with high FLIPI, 73.0% for patients with bulky disease, 83.7% for double refractory and 65.5% for those with high tumor burden. No new safety signals have been reported since the last data cut. Six patients (6.2%) developed second primary malignancies. Conclusions: Four-year follow-up from the ELARA study demonstrates robust and durable responses with tisagenlecleucel and a favorable safety profile. Baseline high-risk disease characteristics are not associated with reduced efficacy following tisagenlecleucel infusion. 1. C.Thieblemont, et al. Blood 2024; 144 (Suppl.1): 3034. ©ASH (2024) Reused with permission.