Annual General Meetingof Shareholders

Roberto BelliniPresident and Chief Executive OfficerTwitter: @rbellini

May 12, 2016

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Forward Looking StatementsCertain statements contained in this presentation, 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 obtain financing, the impact of general economic conditions, general conditions in the pharmaceutical industry, changes in the regulatory environment in the jurisdictions in which the 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, dependence on Auven Therapeutics for the completion of the KIACTA™ Phase 3 Confirmatory Study 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 the KIACTA™ Phase 3 Confirmatory Study and the sharing of proceeds between Auven Therapeutics and BELLUS Health Inc. from potential future revenue of KIACTA™ are dependent upon a number of factors, including the quantum of proceeds. Consequently, actual future results and events may differ materially from the anticipated results and events expressed in the forward-looking statements. The Company 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 presentation. 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.

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At BELLUS, we are focused on developing drugs for rare diseases starting with conditions that affect the kidneys.

Value driving rare disease pipeline fully funded through key milestones

Company Highlights

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Late-stage pipeline with 4 projects targeting rare diseases

Lead drug candidate, KIACTA, in Phase 3 Confirmatory Study for AA amyloidosis Rare and deadly kidney disease with no treatment

Phase 2/3 study completed with positive efficacy and clean safety

Similar and confirmatory Phase 3 study completed (Data expected in Q2 2016)

Validating development partner investing $70M in project

Potential exit to commercial partner following Phase 3 data

Business plan fully funded through KIACTA Phase 3 and exit process

Late stage pipeline focused on developing innovative drugs for rare diseases

Pipeline of Products

ShigamabsHUS

DISCOVERY PRECLINICAL PHASE 1 PHASE 2 PHASE 3

KIACTAAA amyloidosis Partnered

MARKET

AL amyloidosis

PartneredKIACTASarcoidosis

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Lead Phase 3 Product Candidate

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A rare and deadly kidney disease with no specific treatment

FOR AMYLOID A (AA) AMYLOIDOSIS

Disease and Mechanism of Action

CHRONIC INFLAMMATION

SERUM AMYLOID APRECURSOR (SAA) PROTEIN

AA PROTEIN + GLYCOSAMINOGLYCANS (GAGs)

ORGAN DAMAGE, IN PARTICULAR TO KIDNEYS LEADING TO DIALYSIS

REDUCTION IN FIBRIL FORMATION & DEPOSITION

Converts toAA Protein

Generatescytokine cascade

(TNFα / IL-1 / IL-6) and increases SAA levels

Rheumatic ConditionsInflammatory Bowel DiseaseChronic InfectionsFamilial Mediterranean Fever

KIACTA™ blocksAA + GAGs interaction

Systemic Amyloid A Fibril Formation & Deposition

KIACTA designed to bind AA amyloid, slow down disease progression and delay dialysis 7

Patient Population

Source: Navigant Consulting 2014

10,000-15,000

potential KIACTATM patients in the United States and Europe

MARKET RESEARCHNavigant Consulting conducted extensive primary and secondary research including over 60 interviews with treating physicians and key opinion leaders in the United States and Europe

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HR 0.58 0.41 0.48 0.54 0.95

95% C.I 0.37, 0.93 0.19,0.86 0.28,0.82 0.22,1.37 0.27,3.29

P value 0.025 0.019 0.008 0.20 0.94

Graphical representation of the information in this table

Composite Endpoint (Time to

First Worse Event)

Doubling Serum

Creatinine

50%DecreaseCreatinine Clearance

Dialysis/ESRD Death

Num

ber o

f Pat

ient

Eve

nts

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*

*

**

KIACTA - Robust Clinical Results in Phase 2/3

*p<0.05 **p<0.01Dember et al. June 7, 2007. New England Journal of Medicine. Vol 356 (23) 2349-2360.

Landmark study in AA amyloidosis: 183 patients treated for 2 years

Important benefits for patients on drug:

Statistically significant (p-value=0.025) reduction in number and risk of reaching worsening kidney event

Important delay in reaching dialysis

Experienced and knowledgeable partner working on lead project

Auven is a global biotech private equity group

Partnered on KIACTA project in 2010

Funding 100% of KIACTA project including studies in AA Amyloidosis and Sarcoidosis

≥ US$70M in investments

Overall proceeds of exit expected to be shared 50-50

KIACTA to be sold/partnered to commercial entity after Phase 3 Confirmatory Study results

Auven Therapeutics Partnership for KIACTA

BUSINESS PLANAUVEN PARTNERSHIP

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PHASE 3 CONFIRMATORY STUDYKey entry criteria based on kidney function: High proteinuria (>1 g/d) or low

creatinine clearance (< 60 ml/min/1.73m2)

183 patients in 13 countries

Fixed treatment duration of 2 years 74 kidney function worsening

events

PHASE 2/3 STUDY

Enriched patient population High proteinuria (>1 g/d)

More patients 261 patients in >25 countries

Increased power Event driven trial to conclude on

reaching 120 events

KIACTA – Phase 3 Confirmatory Study

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Key improvements made to increase chance of successful study

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Study enrolled with 261 patients

Study completed with 120 events reached (January 2016)

Last Patient Last Visit in March 2016

Topline data expected in Q2 2016

Phase 3 Confirmatory Study

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Second KIACTA Indication – Sarcoidosis

INDICATION

DEVELOPMENT

Chronic sarcoidosis, a rare disease that causes lung scarring and decreased lung functionKIACTA target Serum Amyloid A plays key role in disease

Partnered with AuvenAgreement with Mount Sinai Hospital New York to start Phase 2/3 studyIND filing expected in 2016

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Second Rare Disease Product Candidate

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A rare disease primarily affecting the kidneys of children

FOR STEC RELATEDHEMOLYTIC UREMIC SYNDROME (SHUS),

SHIGAMABSHIGAMAB

Disease Course and Mechanism of Action

E. COLI INGESTION

GUT COLONIZATION AND SECRETION OF TOXIN INTO BLOODSTREAM

TOXIN MAY BE CARRIED BY PMNs IN BLOODSTREAMSYMPTOMS: BLOODY DIARRHEA

SHIGAMAB BINDING NEUTRALIZES TOXIN WHICH IS THEN ELIMINATED

Shigamab Antibody

Day -4 Day 0 Day 4 Day 8

TOXIN BINDS TO GB3 RECEPTORS ON KIDNEY LEADING TO STEC-HUS. OUTCOMES: -CHRONIC KIDNEY DISEASE / HYPERTENSION: 40%-ENCEPHALOPATHY / DEATH: 5%-RESOLUTION: 55%

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90%

SPONTANEOUSRESOLUTION

10%

SHIGAMAB TREATMENT

Mice rescued from shigatoxin induced weight loss and kidney injury up to 4 days post intoxicationData presented at VTEC conference in September 2015

Shigamab Overview

NEXT STEPS (12 MONTHS)

MARKET OPPORTUNITY

CLINICAL

Further animal model data in treatment of sHUSMeetings with regulators to agree on clinical development plan

2,000-3,000 estimated annual cases of sHUS in developed countries, principally children$100-200 million annual sales opportunity

Safe and well tolerated in target pediatric population

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PRE- CLINICAL

Clean capital structure and cash runway through potential exit

Corporate

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Capital Markets (as of May 9th, 2016)

Ticker TSX: BLU

Shares (Basic) 54.7M

Shares (Fully Diluted) 65.9M

Daily Volume ~100K

Market Capitalization (FD) ~C$150M

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Finance

Cash (December 31, 2015) C$9.7M

Burn rate (monthly) <C$300K

Shareholder Ownership (FD)

Bellini Family ≈ 33%

Power Corporation ≈ 27%

Pharmascience ≈ 10%

Governance and Shareholders

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Board of Directors Company / Experience

Dr. Francesco Bellini (Chair)

Franklin Berger

Charles Cavell

Hélène Fortin

Pierre Larochelle

Muriel Lortie

Joseph Rus

Dr. Martin Tolar

Roberto Bellini

Management Title

Roberto Bellini President and Chief Executive Officer

Dr. Denis Garceau Senior Vice President, Drug Development

François Desjardins Vice President, Finance

Tony Matzouranis Vice President, Business Development

LAROSE FORTIN CA Inc.

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Potential KIACTA exit

Continue executing KIACTA for AA Amyloidosis plan:

Reach 120 event target (Q1 2016)

Top Line Data (Q2 2016)

Progress rare disease pipeline projects:

IND filing for KIACTA Phase 2/3 for Sarcoidosis (2016)

Shigamab animal data (1H 2016)

Shigamab clinical trial design (1H 2016)

Significant news flow and value inflection point in 2016

Milestones

Past Execution

Attractive partnership for KIACTA

Execution of global KIACTA Phase 3 Confirmatory Study

Expansion of rare disease pipeline

Strong balance sheet and clean capital structure

Milestones

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