Real-world outcomes of lisocabtagene maraleucel (liso-cel) in patients (pt) with relapsed or refractory (R/R) chronic lymphocytic leukemia (CLL): First results from CIBMTR.

7024 Background: Liso-cel is an autologous, CD19-directed CAR T cell product with established efficacy and safety across B-cell malignancies. In TRANSCEND CLL 004 (NCT03331198), liso-cel demonstrated promising efficacy and manageable safety in pts with R/R CLL, including those previously exposed to Bruton tyrosine kinase inhibitor (BTKi) and B-cell lymphoma 2 inhibitor (BCL2i). Here, we report real-world effectiveness and safety of liso-cel in pts with R/R CLL. Methods: This observational study evaluated US pts with R/R CLL who received commercial liso-cel (05/2024–09/2025) and had ≥ 1 postinfusion assessment reported to CIBMTR. Effectiveness outcomes were ORR, CR rate, duration of response (DOR), PFS and OS; safety outcomes included AEs of special interest, nonrelapse mortality (NRM) and death. Results are descriptive. Results: Of 45 eligible pts, 64% were male; median age was 62 y (range, 44–83; ≥ 65 y, 44%). In pts with available data, all had ECOG PS 0–1 (43/43) and 57% (21/37) had ≥ 1 comorbidity, most commonly (> 10%) cardiac (24%) or pulmonary (16%). Elevated LDH was observed in 35% (15/43) and unmutated IGHV in 91%. Pts had a median of 6 (range, 1–10) prior therapies and 71% received liso-cel as fifth-line or later treatment (tx). Most pts (84%) were previously exposed to covalent BTKi and BCL2i, and nearly half (47%) had prior pirtobrutinib tx. Bridging therapy was used in 48% (21/44) of pts. At a median (95% CI) follow-up of 6.0 mo (5.4–7.1), ORR was 84% (70–93), and CR rate was 55% (39–70); 81% (13/16) of pts in CR with available data were MRD negative. Median (95% CI) DOR, PFS, and OS were not reached. Among responders (n = 36), 6-mo DOR was 89% (70–96.5); 6-mo PFS and OS were 77% (60–87) and 87% (72–95), respectively. Among pts with any-grade (gr) cytokine release syndrome (80%; gr ≥ 3, 4%) or immune effector cell–associated neurotoxicity syndrome (36%; gr ≥ 3, 13%), no gr 5 events occurred. Clinically significant infections were reported in 40% of pts, and at 30 d after infusion, 18% had persistent gr 4 thrombocytopenia and/or neutropenia. Rates were low of HLH/MAS (7%), second primary malignancies (2%; 1 case of basal cell carcinoma 34 d postinfusion), tumor lysis syndrome (7%), and gr 3/4 organ toxicity (9%). Of the 5 deaths, 2 each were due to relapse/progression or infection, and 1 pt had multiple causes reported; 6-mo NRM was 5% (95% CI, 0.8–14). Among the 49% of pts intended for outpatient infusion, 55% (12/22) were hospitalized postinfusion, with a median (range) time to hospitalization of 5.5 d (1–20) and a stay of 5.5 d (1–26). Conclusions: In routine clinical practice, liso-cel demonstrated response rates higher than in clinical trials, with a consistent safety profile. These real-world data support liso-cel as an effective option for pts with R/R CLL, including heavily pretreated or high-risk pts, and the potential for outpatient administration.