BELLUS Health Presents Phase 1 Data for BLU-5937, its Lead Product Candidate for the Treatment of Refractory Chronic Cough, at the American Thoracic Society International Conference

May 21, 2019 Off By BusinessWire

– Clinical results conclusively demonstrate that BLU-5937, a highly
selective P2X3 antagonist, is a differentiated product candidate that
has little to no impact on taste perception –

– Clinical Phase 2 study to assess the efficacy, safety and
tolerability of BLU-5937 in chronic cough patients is expected to begin
in mid-2019 –

LAVAL, Quebec–(BUSINESS WIRE)–BELLUS Health Inc. (TSX: BLU) (“BELLUS Health” or the “Company”), a
clinical-stage biopharmaceutical company developing novel therapeutics
for the treatment of chronic cough and other hypersensitization-related
disorders, today presented results from the clinical Phase 1 study of
BLU-5937, an orally-administered P2X3 antagonist, being developed for
the treatment of refractory chronic cough. Clinical data presented at
the American Thoracic Society International Conference in Dallas, Texas
showed that BLU-5937 is well-tolerated and importantly, provide the
first clinical evidence that a highly selective P2X3 antagonist is
associated with little to no impact on taste.

Data presented, in the form of a poster presentation entitled “BLU-5937
a Highly Selective P2X3 Homotrimeric Receptor Antagonist with Improved
Taste Safety Profile in Healthy Subjects,” may be accessed on the Events
and Presentations
page under the Investors & News section of the
Company’s website at www.bellushealth.com.

“The results of this study represent a significant advancement in the
field of anti-tussive research and further validate the hypothesis that
a highly selective P2X3 antagonist does not lead to taste disturbance
side effects,” commented Dr. Denis Garceau, Senior Vice-President, Drug
Development of BELLUS Health. “This ability to maintain taste function
represents a significant competitive advantage since it will translate
to improved tolerability and therefore a higher compliance rate in a
patient population that is in great need of a safe and effective
therapy.”

The Phase 1 study was a randomized, double-blind, placebo-controlled
study of 90 healthy adult subjects. Participants were divided into 6
single ascending dose (SAD; n=60) and 3 multiple ascending dose (MAD;
n=30) cohorts. The primary objectives were to assess the safety,
tolerability (including taste perception), and pharmacokinetic profile.
BLU-5937 was found to be safe and well-tolerated at all doses, with very
low incidence of transient and sporadic taste adverse events. Specific
results showed:

  • Based on human pharmacokinetic profile seen in the Phase 1 study and
    achieving dose levels required to reach optimal efficacy in the
    preclinical cough models, the anticipated therapeutic doses of
    BLU-5937 are expected to be 50mg – 100mg BID;
  • At the anticipated therapeutic doses of 50mg – 100mg BID, BLU-5937 did
    not cause any loss of taste perception and only one subject out of 24
    (4.2%) reported transient taste alteration. No subject reported total
    loss of taste at any dose;
  • There were no cases of taste alteration or taste loss at 200mg BID;
  • Incidence of taste alteration was higher at supra-therapeutic doses (≥
    400mg) and analysis of drug blood levels suggests it may correlate
    with drug exposure that partially inhibits P2X2/3 receptors;
  • In the MAD cohorts, five subjects (4 at 400mg BID; 1 at 100mg BID)
    experienced taste alteration events: all 5 subjects reported a taste
    event on the first dose; 3 of them experienced a second episode during
    the 7-day dosing period and 2 had no further event;
  • There were no serious adverse events (SAE) reported, and no subjects
    withdrew prematurely due to an adverse event (AE). Overall incidence
    of AEs was comparable between placebo (50%) and BLU-5937 (44%). The
    other most frequent AEs (>5%) were: taste alteration (19.4%), headache
    (11.1%), numbness (11.1%), nausea (8.3%), dizziness (5.6%) and
    heartburn (5.6%);
  • No significant trends of mean changes in vital signs,
    electrocardiogram (ECG), and clinical laboratory values were observed.

Results from the Phase 1 study support the advancement to a Phase 2
study, which is expected to be initiated in mid-2019, with top-line
results anticipated in mid-2020. This will be a dose-escalation,
crossover design study to assess the efficacy, safety, and tolerability
of BLU-5937 at four doses: 25, 50, 100, and 200mg BID. In the Phase 1
study, 2.5% of subjects tested at these doses had a taste alteration
event. Approximately fifty patients with refractory unexplained chronic
cough are expected to be enrolled at 12 clinical sites in the United
Kingdom and United States.

About BLU-5937

BLU-5937, a highly selective P2X3 antagonist – (>1500 fold) for human
P2X3 receptors versus P2X2/3 receptors – has the potential to be a
best-in-class therapeutic for refractory chronic cough patients.

The P2X3 receptor in the cough reflex pathway is a rational target for
treating refractory chronic cough, and it has been validated in multiple
clinical studies. With a modestly-selective P2X3 antagonist therapy for
chronic cough, an adverse effect on taste perception is a well-known and
widely-documented tolerability issue. The Company believes that a highly
selective P2X3 antagonist can reduce coughing in patients with
refractory chronic cough, while maintaining taste function, by not
inhibiting P2X2/3 receptors.

In addition to chronic cough, BLU-5937 may potentially have clinical
benefit in other afferent hypersensitization-related disorders, such as
visceral pain, hypertension, and migraine, among others. BELLUS Health
is exploring how P2X3 activation can contribute to irritation and pain,
and how inhibition of P2X3 receptors may be able to help treat these
afferent hypersensitization-related disorders.

About BELLUS Health (www.bellushealth.com)

BELLUS Health is a clinical-stage biopharmaceutical company developing
novel therapeutics for the treatment of chronic cough and other
hypersensitization-related disorders. The Company’s lead product
candidate, BLU-5937, is being developed for the treatment of chronic
cough.

Chronic cough is a cough lasting more than eight weeks and is associated
with significant adverse physical, social and psychosocial effects on
health and quality of life. It is estimated that approximately 26
million adults in the United States suffer from chronic cough with more
than 2.6 million having unexplained or refractory chronic cough lasting
for more than a year. There are limited treatment options for refractory
chronic cough and no currently approved therapeutics.

Forward-Looking Statements

Certain statements contained in this news release, other than statements
of fact that are independently verifiable at the date hereof, may
constitute “forward-looking statements” within the meaning of Canadian
securities legislation and regulations. Such statements, based as they
are on the current expectations of management, inherently involve
numerous important risks, uncertainties and assumptions, known and
unknown, many of which are beyond BELLUS Health Inc.’s control. Such
risks factors include but are not limited to: the ability to expand and
develop its project pipeline, the ability to obtain financing, the
impact of general economic conditions, general conditions in the
pharmaceutical industry, changes in the regulatory environment in the
jurisdictions in which BELLUS Health Inc. does business, stock market
volatility, fluctuations in costs, changes to the competitive
environment due to consolidation, achievement of forecasted burn rate,
potential payments/outcomes in relation to indemnity agreements and
contingent value rights, achievement of forecasted pre-clinical and
clinical trial milestones and that actual results may vary once the
final and quality-controlled verification of data and analyses has been
completed. In addition, the length of BELLUS Health Inc.’s product
candidates’ development process, their market size and commercial value,
as well as the sharing of proceeds between BELLUS Health Inc. and its
potential partners from potential future revenues, if any, are dependent
upon a number of factors. Consequently, actual future results and events
may differ materially from the anticipated results and events expressed
in the forward-looking statements. BELLUS Health Inc. believes that
expectations represented by forward-looking statements are reasonable,
yet there can be no assurance that such expectations will prove to be
correct. The reader should not place undue reliance, if any, on any
forward-looking statements included in this news release. These
forward-looking statements speak only as of the date made, and BELLUS
Health Inc. is under no obligation and disavows any intention to update
publicly or revise such statements as a result of any new information,
future event, circumstances or otherwise, unless required by applicable
legislation or regulation. Please see BELLUS Health Inc.’s public
filings with the Canadian securities regulatory authorities, including
the Annual Information Form, for further risk factors that might
affect BELLUS Health Inc. and its business.

Contacts

Investors:
BELLUS Health
François
Desjardins
Vice-President, Finance
450-680-4525
[email protected]

Solebury Trout
Chad Rubin
646-378-2947
[email protected]

Media:
Solebury Trout
Brad Miles
646-513-3125
[email protected]