BELLUS Health : Corporate Presentation – February 2023

Investor Presentation

NASDAQ/TSX - BLU

February 16th, 2023

Forward Looking Statements

Certain statements contained in this presentation, other than statements of fact that are independently verifiable at the dat e hereof, may constitute "forward-looking statements" within the

meaning of Canadian securities legislation and regulations, the U.S. Private Securities Litigation Reform Act of 1995, as ame nded, and other applicable securities laws. Forward-looking statements are frequently, but not always, identified by words such as "expects," "anticipates," "believes," "intends," "esti mates," "potential," "possible," "projects," "plans," and similar

expressions. Such statements, based as they are on the current expectations of management, inherently involve numerous import ant risks, uncertainties and assumptions, known and unknown, many of which are beyond BELLUS Health Inc.'s ("BELLUS Health") control. Such statements include, but are not limite d to, the potential of camlipixant (BLU-5937) to successfully treat refractory chronic cough ("RCC") and other hypersensitization-related disorders and benefit such patients, BELLUS Health's expectations related to its preclinical studies and clinical trials, including the timing of initiation of and the design of the Phase 3 clinical trials of camlipixant in RCC, the timing and outcome of interactions with regulatory agencies, the potential activity and tolerability profile, selectivity, potency and other characteristics of camlipixant, including as compared to other competitor candidates, especially where head-to-head studies have not been conducted and cross-trial comparisons may not be directly comparable due to differences in study protocols, conditions and patient populations, the commercial potential of camlipixant, including with respect to patient population, pricing and labeling, BELLUS Health's financial position and sufficiency of cash resources to bring BELLUS Health through topline results of CALM-1 and CALM-2 clinical trials, and the potential applicability of camlipixant and BELLUS Health's P2X3 platform to treat other disorders. Risk factors that may affect BELLUS Health's future results include but are not limited to: the benefits and impact on label of its enrichment strategy, estimates and projections regarding the size and opportunity of the addressable RCC market for camlipixant, the ability to expand and develop its project pipeline, the ability to obtain adequate financing, the ability of BELLUS Health to maintain its rights to intellectual property and obtain adequate protection of future products through such intellectual property, the impact of general economic conditions, general conditions in the pharmaceutical industry, the impact of the ongoing COVID-19 pandemic on BELLUS Health's operations, plans and prospects, including to the initiation and completion of clinical trials in a timely manner or at all, changes in the regulatory environment in the jurisdictions in which BELLUS Health does business, supply chain impacts, stock market volatility, fluctuations in costs, changes to the competitive environment due to consolidation, achieve ment of forecasted burn rate, achievement of forecasted preclinical study and clinical trial milestones, reliance on third parties to conduct preclinical studies and clinical trials for camlipixant and that actual results may differ from topline results once the final and quality-controlled verification of data and analyses has been completed. In addition, the length of BELLUS Health's product candidate's development process and its market size and commercial value are dependent upon a number of factors. Moreover, BELLUS Health's growth and future prospect s are mainly dependent on the successful development, patient tolerability, regulatory approval, commercialization and market acceptance of its product candidate camlipixant and other products. Consequently, actual future results and events may differ materially from the anticipated results and events expressed in the forward-looking statements. BELLUS Health 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 re ader should not place undue reliance, if any, on any forward-looking statements included in this presentation. These forward-looking statements speak only as of the date made, and BELLUS Health 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 oth erwise, unless required by applicable legislation or regulation.

Please see BELLUS Health's public filings with the Canadian securities regulatory authorities, including, but not limited to, its Annual Information Form, and the United States Securities and Exchange Commission, including, but not limited to, its Annual Report on Form 40 -F, for further risk factors that might affect BELLUS Health and its business.

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Company Overview

BELLUS Health - A Leader in the Development of The Novel P2X3 Antagonist Class Targeting Cough Hypersensitivity

Drug in Development: Camlipixant (BLU-5937)

• Oral P2X3 antagonist with potential best-in-class profile

Lead Indication - Refractory Chronic Cough (RCC)

• Persistent cough >8 weeks that does not respond to treatment for underlying condition or is unexplained
• Compelling results from the SOOTHE Phase 2b trial (Dec 2021)
• First patients randomized in the Phase 3 CALM program (CALM-1 and CALM-2) in 4Q 2022
• Population estimated at ~9M in the U.S., a large and growing market with limited competition

Key Upcoming Events

• Topline results from CALM-1 and CALM-2 expected in 2H 2024 and 2025, respectively
• Topline results from Phase 1 QD formulation expected in 1H 2023
• Analyst Day planned for mid-2023

Intellectual Property

• Patents granted to 2034 (composition of matter) and 2038 (method of use)
• 100% ownership of global rights

Pipeline in a Product	Financials
• Potential to study camlipixantin other cough indications		•	US$364.4M cash position
		•	Cash runway to 2H 2025

Strong Leadership and Advisory Group

Management

Roberto Bellini

President & Chief Executive Officer

Dr. Catherine Bonuccelli, MD

Chief Medical Officer

Ramzi Benamar, MBA

Chief Financial Officer

Dr. Denis Garceau, PhD

Chief Scientific Officer

Dr. Andreas Orfanos, MBBCh, MBA, FFPM

Chief Operations Officer

Tony Matzouranis

Senior Vice President, Business Development

Board of Directors

Dr. Francesco Bellini, PhD	Roberto Bellini
Chair
Dr. Youssef Bennani, PhD	Franklin Berger
Dr. Clarissa Desjardins, PhD	Pierre Larochelle
Dr. Bill Mezzanotte, MD, PhD	Joseph Rus

Clinical Advisory Board

CHRONIC COUGH

Dr. Jacky Smith (Chair) , MB, ChB, FRCP, PhD	Dr. Michael S. Blaiss, MD
Manchester University	Medical College of Georgia
Dr. Surinder Birring, MB ChB (Hons), MD	Dr. Peter Dicpinigaitis, MD
King's College London	Albert Einstein Medical College

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