Bezuclastinib

SUMMIT Part 2 randomized 179 participants, 119 to bezuclastinib and 60 to placebo. Reported mean TSS reductions at week 24 were 24.3 and 15.4 points, respectively (p=0.0002). At least 50% TSS reduction occurred in 34.3% versus 18.1%. In the intention-to-treat biomarker analysis, at least 50% serum tryptase reduction occurred in 104/119 participants (87.4%) versus 0/60. Hair color change occurred in 69.5% versus 5.0%; ALT/AST elevations occurred in 22.0% versus 6.6%. Treatment-related discontinuations occurred in 5.9% of bezuclastinib recipients, all due to transaminase elevations that subsequently resolved.