– Study Results Expected in the Fourth Quarter of 2018

LAVAL, Canada I July 9, 2018 I BELLUS Health Inc. (TSX: BLU) (“BELLUS Health” or the “Company”), a biopharmaceutical development company advancing novel therapeutics for conditions with high unmet medical need, today announced the initiation of healthy subjects dosing in a Phase 1 clinical study for BLU-5937, its lead drug candidate for the treatment of chronic cough. Preclinical studies demonstrated that BLU-5937 is a highly selective P2X3 antagonist exhibiting a potent anti-tussive effect without affecting taste perception, with an excellent safety profile.

The main objectives of the Phase 1 clinical study are to assess the safety, tolerability (including taste perception) and pharmacokinetic profile of BLU-5937 in healthy subjects. This is a randomized, double-blind, placebo-controlled study of orally administered BLU-5937 in up to 90 healthy adult subjects.

“We are excited to begin the first-in-human study of our lead drug candidate BLU-5937,” said Roberto Bellini, president and CEO of BELLUS Health. “We expect top-line Phase 1 data in the fourth quarter of 2018, where positive results would solidify BLU-5937’s potential as a best in class P2X3 antagonist for chronic cough.”

The study will be divided in two parts

Part 1: A single-ascending dose (“SAD”) study will be conducted in up to 60 healthy subjects. Subjects will be randomized into up to 6 cohorts of 10 subjects (8 BLU-5937: 2 placebo).

Part 2: A multiple-ascending dose (“MAD”) study will be conducted in up to 30 healthy subjects. Subjects will be randomized into up to 3 cohorts of 10 subjects (8 BLU-5937: 2 placebo). Each subject will receive daily oral administrations of the assigned treatment for 7 consecutive days. The dose regimen for the MAD study will be established based on the SAD study results.

Results of the Phase 1 clinical study are expected in the fourth quarter of 2018. These results will help define BLU-5937’s expected product profile, including the safety, tolerability (including taste perception) and dosing regimen for the Phase 2 proof-of-concept study.

The Phase 2 proof-of-concept study is expected to be initiated in 2019 in chronic cough patients. This will be a dose escalation study to assess the safety, tolerability and efficacy of BLU-5937.

About BLU-5937 for Chronic Cough

BLU-5937 is a potent, highly selective, orally bioavailable small molecule antagonist of the P2X3 receptor, a clinically validated target for chronic cough. BLU-5937 has the potential to be a best-in-class therapeutic for chronic cough patients who do not respond to current therapies.

In two separate preclinical models, BLU-5937 showed a significant reduction in cough and no taste loss side effect. In a guinea pig cough model, BLU-5937 showed comparable anti-tussive efficacy to the current leading P2X3 antagonist in development, Merck & Co’s gefapixant (also named AF-219 or MK-7264). In a rat taste model, BLU-5937 was not associated with taste loss whereas, consistent with clinical trial data previously presented by Merck & Co, gefapixant led to significant taste loss.

The preclinical toxicology studies demonstrated an excellent safety profile for BLU-5937.

BLU-5937 has obtained patent protection with claims covering the composition of matter of BLU-5937 in three of the four major pharmaceutical markets (U.S., China and Europe), with an expiration date of 2034.   Similar patent applications are currently pending in Japan and other industrialized nations.

About BELLUS Health (www.bellushealth.com)

BELLUS Health is a biopharmaceutical development company advancing novel therapeutics for conditions with high unmet medical need. Its pipeline of projects includes the Company’s lead drug candidate BLU-5937 for chronic cough and several other partnered clinical-stage drug development programs. BLU-5937, a highly selective P2X3 antagonist, has the potential to be a best-in-class therapeutic for chronic cough patients who do not respond to current therapies.

Chronic cough is a cough that lasts more than eight weeks and is associated with significant adverse social, psychosocial and physical effects on quality of life. A recent commercial assessment performed by Torreya Insights on behalf of the Company concluded that, in the United States alone, more than 26 million adults have chronic cough and more than 2.6 million of these patients suffer from refractory chronic cough lasting for more than a year.

SOURCE: BELLUS Health