P874: LONG-TERM REMISSION AND SURVIVAL IN PATIENTS WITH RELAPSED OR REFRACTORY MULTIPLE MYELOMA AFTER TREATMENT OF LCAR-B38M CAR-T – AT LEAST 5-YEAR FOLLOW-UP IN LEGEND-2

• DOI: 10.1097/01.hs9.0000970400.98418.89
• Publication Date: 2023-08-10T04:07:28Z
• Authors: Jian‑qing MI; Wan‑hong Zhao; Li‑juan Chen; Weijun Fu; Bai‑yan Wang; Jie Xu; Jie Liu; Shi‑wei Jin; Han Zhu; Juan Du; Hua Jiang; Huabin Sun; Yehui Jia; Xiao‑hu Fan; Jian‑yong LI; Jian Hou; Zhu Chen; Wang‑gang Zhang; Ai‑li He; Sai‑juan Chen
• Keywords: Refractory (planetary science)

Topic: 14. Myeloma and other monoclonal gammopathies - Clinical Background: LCAR-B38M CAR-T cells express a structurally differentiated chimeric antigen receptor (CAR) construct containing 4-1BB costimulatory domain 2 BCMA-targeting single-domain antibodies designed to confer avidity. LEGEND-2 was first-in-human phase 1 study of conducted in China, which showed encouraging efficacy manageable safety 74 patients with relapsed or refractory multiple myeloma (RRMM). The US 1b/2 CARTITUDE-1 Chinese CARTIFAN-1 trials ciltacabtagene autoleucel, expresses the same CAR as LCAR-B38M, confirmed observed LEGEND-2. Here, we present ≥5-year follow-up data from LEGEND-2, longest for any BCMA-targeted cell therapy study. Aims: To report after at least 5 years Methods: Study design previously published. All trial provided informed consent. Patients underwent lymphodepletion cyclophosphamide 300 mg/m2 (n=66) 250 plus fludarabine 25 (n=8) prior receiving median dose 0.51 × 106 (range, 0.07-2.10 106) CAR-positive T cells/kg single (n=9) 3 split (n=65) infusions. Results: were enrolled 30 March 2016 26 November 2017. As 2022, 65.4 months 0.4-78.8). had received (median age, 54.5 years; 60.8% male; [range] [1-9] lines [LOT]; 44.6% ISS stage I; 28.4% III; 29.7% extramedullary disease (EMD); 35.7% cytogenetic high risk). No new cell-related toxicities reported analysis. Overall response rate (87.8%), complete (CR) (73.0%), minimal residual disease-negative CR (67.6%), duration (23 months), progression-free survival (18 months) mature reported; overall (OS) not reached. At 65.4-month follow-up, OS 55.8 months, 33 (44.6%) alive 13 (17.6%) still disease-free. Compared progressive (PD) who died, without PD more likely have baseline ECOG performance status (PS) 0, IgG type MM, I numerically shorter time diagnosis, fewer LOT, no light chain EMD (Table). Summary/Conclusion: 18% RRMM disease-free, raising possibility cure this heavily pretreated patient population. Our suggest that are less good functional may experience greater benefit, potentially being cured, therapy. © 2023 American Society Oncology, Inc. Reused permission. This abstract accepted presented ASCO Annual Meeting. rights reserved.Keywords: CAR-T, Phase I, relapsed/refractory, Multiple