Matching-adjusted indirect comparison of efficacy and safety of lisocabtagene maraleucel and mosunetuzumab for the treatment of third-line or later relapsed or refractory follicular lymphoma.

Background: The treatment landscape for relapsed or refractory (R/R) follicular lymphoma (FL) has changed with the introduction of anti-CD19 chimeric antigen receptor T-cell therapies, including lisocabtagene maraleucel (liso-cel) and CD20 × CD3 bispecific T-cell-engaging monoclonal antibodies such as mosunetuzumab. Liso-cel and mosunetuzumab have demonstrated positive benefit-risk profiles for third-line or later (3L+) treatment of patients with R/R FL and are approved treatments for these patients. In the absence of a prospective, randomized study, we conducted an unanchored matching-adjusted indirect comparison (MAIC) to assess the efficacy and safety of liso-cel and mosunetuzumab for 3L+ treatment in patients with R/R FL.

Methods: Unanchored MAICs were performed to estimate relative treatment effects between TRANSCEND FL (NCT04245839) and GO29781 (NCT02500407). For TRANSCEND FL, the leukapheresis set (N = 114) was used for primary comparisons of the following efficacy endpoints: objective response rate (ORR), complete response (CR) rate, duration of response (DOR), and progression-free survival (PFS). The treated set (N = 107) was used for comparisons of the following safety endpoints: cytokine release syndrome (CRS), neurological events (NE), serious infections, and use of corticosteroids or tocilizumab for CRS. Sensitivity analyses were conducted for efficacy using the TRANSCEND FL treated efficacy set (N = 101).

Results: After adjustment, liso-cel was associated with higher ORR (odds ratio [OR] = 3.78, 95% confidence interval [CI] 1.48‒9.67]) and CR rate (OR = 6.46, 95% CI 2.85‒14.65), and improved DOR (hazard ratio [HR] = 0.45, 95% CI 0.26‒0.77) and PFS (HR = 0.28, 95% CI 0.16‒0.49) compared with mosunetuzumab. Results remained consistent across sensitivity analyses. Liso-cel had a lower incidence of grade ≥ 3 CRS (OR = 0.45, 95% CI 0.04‒5.13), grade 3‒4 serious infections (OR = 0.35, 95% CI 0.12‒1.03), and corticosteroid use for CRS management (OR = 0.14, 95% CI 0.03‒0.65); however, liso-cel exhibited higher incidence of any-grade CRS (OR = 1.86, 95% CI 1.01‒3.43), any-grade NEs (OR = 2.16, 95% CI 0.72‒6.44), and tocilizumab use for CRS management (OR = 2.27, 95% CI 0.86‒5.99).

Conclusions: Findings highlight a potential positive benefit-risk profile of liso-cel over mosunetuzumab as a 3L+ treatment for R/R FL.