Tazemetostat in relapsed/refractory follicular lymphoma: a propensity score-matched analysis of E7438-G000-101 trial outcomes

In the tazemetostat E7438-G000-101 trial of relapsed/refractory (R/R) follicular lymphoma (FL), apparent superior efficacy was suggested for mutant-type (MT) versus wild-type (WT) status. However, clinical disparities might have contributed to this conclusion. This study aimed to estimate outcomes after minimizing differences in baseline characteristics. Propensity scores for each participant with WT ( = 54) and MT ( = 45) status were generated based on the likelihood of being selected given their baseline characteristics. Participants were matched using a 1:1 nearest-neighbor approach. The propensity-matched sample included 56 participants (28 WT, 28 MT). Objective response rates (95% confidence interval [CI]) were 35% (22-48) in WT and 69% (55-83) in MT prior to matching and 50% (31-69) in WT and 71% (54-88) in MT after matching. Median progression-free survival values (95% CI) were 11.1 (5.4-16.7) in WT and 13.8 months (11.1-22.1) in MT prior to matching and 14.3 (11.1-∞]) and 14.8 months (10.7-∞]) in WT and MT matched groups, respectively. This analysis suggests that efficacy outcomes for tazemetostat observed in participants with WT R/R FL may have been similar to those in participants with MT had the 2 cohorts been more closely matched.