LEN prolonged progression-free survival (PFS) in pts with RR-DTC in the SELECT trial, and efficacy was maintained in all subgroups. Toxicity was manageable with dose modifications, but whether a longer period of dose interruption might impact the efficacy of LEN was unclear.
In SELECT, pts were randomized 2:1 to receive LEN 24 mg/day or placebo. Pts assigned to LEN were divided into 2 groups: pts with duration of dose interruption
Of 261 LEN-treated pts, there were 134 in group A and 127 in group B. Differences in pt characteristics between groups (A and B) were, respectively: age (>65 years, 33% and 49%), race (Asian, 10% and 25%), and ECOG performance status (0, 64% and 46%). Median duration of dose interruption was 19 days (range: 0–63) and 61 days (range: 2–266) in groups A and B, respectively. Median PFS was not reached (hazard ratio [HR] to placebo: 0.14; 95% CI: 0.09–0.20, P
Longer duration of dose interruption may negatively affect the potential efficacy of LEN. Management of toxicities is essential to avoid long dose interruption. Differences in pt characteristics might confound the results. However, in this analysis LEN achieved improved PFS and ORR compared to placebo, regardless of length of dose interruption.
Clinical trial identification
Legal entity responsible for the study
M. Tahara: Grants and personal fees from Eisai during the conduct of the study and personal fees from Merck Serono, BMS, and Bayer outside the submitted work. M.S. Brose: Grants from Eisai during the conduct of the study. Grants and personal fees from Bayer HealthCare Pharmaceuticals, Exelixis, and Onyx. Grants from Novartis and Roche/Genentech outside the submitted work. L. Wirth: Personal fees from Eisai and Novartis outside the submitted work. T. Suzuki, K. Fujino: Employee of Eisai Co., Ltd. N. Batty, C. Dutcus: Employee of Eisai Inc. A. Gianoukakis: Grants and nonfinancial support from Eisai during the conduct of the study.