Clinical representativeness of pivotal trials for T-cell engagers in relapsed/refractory follicular lymphoma.

Aim: To characterize trial populations of T-cell-engaging therapies, including bispecific antibodies and chimeric antigen receptor T-cell therapies, for relapsed/refractory (R/R) follicular lymphoma (FL) after ≥ 2 systemic therapies and the extent to which they represent real-world R/R FL populations.

Methods: Inclusion/exclusion criteria and baseline characteristics were compared descriptively for EPCORE NHL-1 (epcoritamab, N = 128), GO29781 (mosunetuzumab, N = 90), ELARA (tisagenlecleucel [tisa-cel], N = 97), and ZUMA-5 (axicabtagene ciloleucel [axi-cel], N = 124). Real-world data from the COTA Healthcare (New York, NY) and Optum Market Clarity (Eden Prairie, MN) databases contextualized the clinical representativeness of trial populations.

Results: The epcoritamab trial enrolled a higher proportion of patients who were older, had higher Follicular Lymphoma International Prognostic Index scores, and were more double-refractory versus other trials. Notably, 37% of epcoritamab trial patients would have been excluded from the mosunetuzumab trial, 30% from the tisa-cel trial, and 29% from the axi-cel trial. These excluded subgroups were characterized by factors associated with poor clinical outcomes.

Conclusion: The epcoritamab trial enrolled more broadly and was more representative of typical R/R FL patients than the mosunetuzumab, tisa-cel, and axi-cel trials. Differences in patient characteristics should be considered when evaluating the comparative benefits of T-cell engagers in R/R FL after ≥ 2 systemic therapies.