Mr. Roberto Bellini reports

BELLUS HEALTH ANNOUNCES POSITIVE RESULTS FROM ITS PHASE 1 BIOAVAILABILITY EQUIVALENCE STUDY EVALUATING ONCE-DAILY EXTENDED-RELEASE FORMULATION OF CAMLIPIXANT IN COMPARISON TO TWICE-DAILY IMMEDIATE RELEASE FORMULATION

Bellus Health Inc. has released positive data from its phase 1 bioavailability equivalence study evaluating a once-daily extended release (ER) formulation of camlipixant in comparison with a twice-daily immediate release (IR) formulation. Camlipixant is the company's twice-daily, oral P2X3 antagonist product candidate for the treatment of RCC currently being investigated in the Calm phase 3 program.

The ER formulation demonstrated equivalent bioavailability to the IR formulation, with equivalent total systemic drug exposure (90 per cent geometric mean AUC infinity and 82 per cent geometric mean AUC 24 hours), as well as equivalent minimum drug concentration (88 per cent geometric mean C 24 hours). The ER formulation was well tolerated, with the safety profile consistent with previous camlipixant trials and no taste-related adverse events reported. These results establish proof of concept for developing a once-daily ER formulation of camlipixant. To continue the development of the once-daily ER formulation, the company intends to conduct a multiple dose study of the ER formulation. A patent application has been filed covering once-daily formulations of camlipixant.

"We are pleased with the outcome of the bioavailability equivalence study, which establishes the proof of concept for developing a once-daily formulation of camlipixant, our potentially best-in-class P2X3 inhibitor in phase 3 development," commented Roberto Bellini, president and chief executive officer of Bellus Health. "At Bellus Health, we are working to better the lives of individuals suffering from persistent cough, and these results reflect our continued progress to establish and differentiate camlipixant as the market leading option for RCC patients. We look forward to providing additional data from this study at an upcoming medical conference."

This phase 1, open-label bioavailability equivalence study was designed to assess the safety, tolerability and pharmacokinetic profile of a single dose, once-daily ER formulation of camlipixant versus a twice-daily IR reference formulation (two single doses of 25 milligrams, 12 hours apart) in 16 healthy adult subjects.

About Bellus Health Inc.

Bellus Health is a clinical-stage biopharmaceutical company working to better the lives of patients suffering from persistent cough, starting with the development of camlipixant (BLU-5937) for the treatment of refractory chronic cough (RCC). Camlipixant, the company's lead asset, is an investigational P2X3 receptor antagonist for the treatment of RCC, which is currently being evaluated in the Calm phase 3 clinical program. With no approved treatments in the U.S., camlipixant has the potential to be a breakthrough in the RCC treatment landscape.

Chronic cough is defined as a cough lasting longer than eight weeks. When the cause of chronic cough cannot be identified or the cough persists despite treatment of any associated condition, the condition is referred to as RCC. RCC is a frequent, yet often under-recognized, medical condition that has significant physical, social and psychological consequences on one's quality of life. There are currently no approved treatments for this condition in the United States, European Union or the United Kingdom.

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