Subgroup analyses of primary refractory (refr) vs early relapsed (rel) large B-cell lymphoma (LBCL) from the TRANSFORM study of lisocabtagene maraleucel (liso-cel) vs standard of care (SOC) as second-line (2L) therapy.

Abstract

7526 Background: The TRANSFORM primary analysis (PA; NCT03575351) confirmed the superior efficacy of liso-cel vs SOC as 2L therapy in patients (pts) with primary refr or early rel LBCL (Abramson et al. Blood 2022). Response to first-line (1L) therapy (refr vs rel), which was a study randomization stratification factor, may influence future treatment response. Here, we present results for refr and rel LBCL subgroups from the TRANSFORM PA. Methods: TRANSFORM is a randomized phase 3 study of liso-cel vs SOC (salvage chemotherapy [CT] followed by high-dose CT [HDCT]/autologous SCT [ASCT]) in adults ≤ 75 y with LBCL primary refr to or rel ≤ 12 mo after 1L therapy and eligible for HDCT/ASCT. The primary endpoint was event-free survival (EFS); key secondary endpoints were CR rate, PFS, and OS. In this predefined subgroup analysis, refr was SD, PD, PR, or CR with rel < 3 mo after 1L therapy; rel was CR with rel ≥ 3 mo and ≤ 12 mo after 1L therapy. Results: 92 pts were randomized to each arm. Most pts in the liso-cel and SOC arms had refr disease (73% and 76%, respectively; rel disease, 27% and 24%). Baseline characteristics in the refr and rel subgroups, respectively, were generally balanced: median LDH (U/L; liso-cel, 228.5 and 225; SOC, 259 and 259); median SPD (cm2; liso-cel, 11 and 12; SOC, 15.5 and 18); high-grade B-cell lymphoma (liso-cel, 27% and 16%; SOC, 27% and 9%); diffuse LBCL not otherwise specified (liso-cel, 58% and 56%; SOC, 49% and 73%). Consistent with the overall study population, EFS, CR rate, and PFS favored liso-cel vs SOC in both subgroups (Table). Safety was also consistent. Grade ≥ 3 cytokine release syndrome (CRS) and neurological events (NE) were low in refr (1% and 4%) and rel (0 and 4%) subgroups, respectively, with no grade 4/5 CRS or NEs. Conclusions: In TRANSFORM, liso-cel showed benefits in EFS, PFS, and CR rate vs SOC irrespective of prior response to 1L therapy. As refr LBCL is historically difficult to treat, outcomes for liso-cel in this subgroup are encouraging. Clinical trial information: NCT03575351 . [Table: see text]