Why carry out this study?

Despite the high unmet need among patients with TGCT in China, limited data exist on the use of pexidartinib, a colony-stimulating factor 1 receptor inhibitor, in East Asian patients with TGCT.

In accordance with Chinese regulations, this phase 3 study was designed as a bridging study using the results of the phase 3 ENLIVEN study; it aimed to examine tumor response, joint function, and safety in East Asian patients with TGCT who were treated with pexidartinib.

What was learned from the study?

At week 25, pexidartinib demonstrated clinical benefits (22.5% ORR by RECIST v1.1 and 47.5% ORR per TVS) and improvements in range of motion. ORR by RECIST v1.1 in the phase 3 study was inferior to the ORR at week 25 in the phase 3 ENLIVEN study, but the ORR by RECIST v1.1 at week 37 in the phase 3 study increased to 35.0%, which is close to the ORR at week 37 in the phase 3 ENLIVEN study.

With continuous treatment, pexidartinib has clinically important effectiveness in controlling tumors. Because TGCT is a nonmalignant tumor that progresses continuously and slowly, the result of ORR at week 37 in this study is meaningful for relative long-term tumor control of East Asian patients with TGCT. The safety result was consistent with previous studies, and hepatotoxicity was managed through frequent liver function monitoring and dose-modification guidelines.

This study supports the use of pexidartinib in East Asian patients with TGCT from the Chinese mainland and Taiwan and informs the medical management of TGCT in this population.