FDA accepts review of Biohaven’s ataxia drug, boosting shares as ArriVent’s lung cancer trial miss drags its stock down

Biohaven saw its shares jump after the FDA agreed to review its rare‑disease drug for spinocerebellar ataxia. The regulator’s decision lifted the stock by roughly 25% in late October, offering the company a fresh chance to advance the therapy.

The investigational treatment, known as troriluzole, has faced setbacks before. In 2023 the FDA declined to even review the new drug application after a Phase 3 trial missed its primary endpoint. The recent acceptance marks a reversal that could revive the program.

In contrast, ArriVent BioPharma experienced a sharp decline after its lead lung‑cancer candidate failed to meet goals in a Phase 3 study. The miss sent the stock tumbling, and the decline continued despite early, encouraging data from a separate antibody‑drug conjugate program.

The divergent outcomes highlight how regulatory signals and trial readouts can move biotech valuations dramatically within a single month.