What happened

Shares of Bellus Health (BLU), a clinical-stage biotechnology company, are soaring in response to positive clinical-trial data. Investors excited about the company's lead candidate BLU-5937 drove the stock 58.4% higher as of 10:30 a.m. ET on Monday.

So what 

Bellus Health's lead candidate is a potential first-in-class P2X3 inhibitor for the treatment of refractory chronic cough (RCC) and eczema-related itching. The  biotech stock is up sharply today because 28 days of treatment with BLU-5937 led to a significant improvement to RCC patients' daily cough frequency during the phase 2 Soothe trial. Compared to patients in the placebo group, Soothe participants randomized to receive 50 mg of BLU-5937 twice a day reduced their cough frequency by 34.4%.

Scientists discusing clinical trial results.

Image source: Getty Images.

The P2X3 receptors that regulate an urge to cough are closely related to P2X2/3 receptors that play a role in our ability to taste. BLU-5937 is intended to selectively act on P2X3 receptors in order to preserve patients' ability to taste and appears to work in this regard. None of the patients treated with BLU-5937 reported taste-loss problems.

Bellus Health stock probably would have soared much higher if not for disappointing news from the phase 2 Blueprint trial with eczema patients. Treatment with BLU-5937 didn't lead to a statistically significant itchiness reduction for eczema patients.

Now what

Bellus Health's next step will be an end of phase 2 meeting with the Food and Drug Administration (FDA) to discuss the design of an upcoming phase 3 RCC trial with its lead candidate. That means the company could have phase 3 data in hand before the end of 2022.

An estimated 9 million Americans suffer from a chronic cough and there aren't any specific therapies approved to treat the debilitating condition. Following today's phase 2 results, it looks like Bellus could be the first to launch an RCC treatment if a deep-pocketed pharmaceutical company doesn't license marketing rights to BLU-5937 first or buy the entire company at a premium.