Bloom Burton Healthcare Investor Conference

Roberto BelliniPresident and Chief Executive OfficerTwitter: @rbellini

May 2, 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. Such statements, based as they are on the current expectations of management, inherently involve numerous risks and uncertainties, known and unknown, many of which are beyond BELLUS Health Inc.'s control. Such risks 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 in relation to indemnity agreements, achievement of forecasted 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 the KIACTA™ Phase III Confirmatory Study is dependent upon many factors, including clinical sites activation, patient enrollment rate, patient drop-out rate and occurrence of clinical endpoint events, and the sharing of proceeds between Auven Therapeutics and BELLUS Health Inc. from potential future revenue of KIACTA™ is dependent upon a number of factors, including the quantum of proceeds. Consequently, actual future results may differ materially from the anticipated results expressed in the forward-looking statements. The reader should not place undue reliance, if any, on any forward-looking statements included in this presentation. These statements speak only as of the date made and BELLUS Health Inc. is under no obligation and disavows any intention to update or revise such statements as a result of any event, circumstances or otherwise, unless required by applicable legislation or regulation. Please see BELLUS Health Inc.’s public fillings 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 III Confirmatory Study for AA amyloidosis Rare and deadly kidney disease with no treatment

Phase II/III study completed with positive efficacy and clean safety

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

Potential peak market sales of $600M-$1B

Potential exit to commercial partner following Phase III data

Business plan fully funded through KIACTA Phase III and exit process

Late stage pipeline focused on developing innovative drugs for rare diseases

Pipeline of Products

ShigamabsHUS

DISCOVERY PRECLINICAL PHASE I PHASE II PHASE III

KIACTA™AA amyloidosis

MARKET

AL amyloidosis

KIACTA™Sarcoidosis

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Lead Phase III 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

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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

KIACTA™ – Addressable Market

Source: Navigant Consulting 2014 8

Estimated Peak Annual Sales

$600 Million-$1Billion

KIACTA Eligible Patients

10-15 Thousand

Expected Pricing Per Patient Per Year

$200-$275 Thousand

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 III Confirmatory Study results

Auven Therapeutics Partnership for KIACTA™

BUSINESS PLANAUVEN PARTNERSHIP

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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

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

Composite endpoint based on patients reaching events of decreasing kidney function or death

Statistically significant primary endpoint (Cox Proportional Hazard Ratio; p=0.025)

Clinically meaningful treatment effect with 42% reduction in risk of reaching worsening kidney event

Clear regulatory path to approval based on confirmatory study

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 II/III

*p<0.05 **p<0.01

PHASE III 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

Composite primary endpoint based on patients reaching kidney function worsening events Target statistical significance of p=0.01

PHASE II/III STUDYEnriched 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

Lower statistical bar to achieve success Primary endpoint with target statistical

significance of p=0.05

KIACTA™ – Phase III 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)

Topline data expected in Q2 2016

Phase III Confirmatory Study

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Clean capital structure and cash runway through potential exit

Corporate

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Capital Markets (as of April 28th, 2016)

Ticker TSX: BLU

Shares (Basic) 54.7M

Shares (Fully Diluted) 65.7M

Daily Volume ~100K

Market Capitalization (FD) ~C$110M

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Finance

Cash (December 31, 2015) C$9.7M

Burn rate (monthly) <C$300K

Shareholder Ownership (FD)

Bellini Family ≈ 29%

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 for Sarcoidosis (1H 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 III Confirmatory Study

Expansion of rare disease pipeline

Strong balance sheet and clean capital structure

Milestones

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