Why Bellus Health Stock Tanked 69.2% Today

Shares of Bellus Health (NASDAQ: BLU) (TSX: BLU) were falling 69.2% at 2:40 p.m. EST on Monday following its announcement that a phase 2 trial of BLU-5937 as a treatment for refractory chronic cough has missed its mark. The biotech company says millions of patients suffer from chronic cough despite existing treatments, including Merck's (NYSE: MRK) gefapixant, a P2X3 antagonist associated with a side effect of taste loss that's hindered its use. Unfortunately, BLU-5937 wasn't able to outperform placebo when it came to reducing the frequency of cough while awake in its phase 2 study.