Leerink Partners Healthcare ConferenceDavid Meeker, M.D. – Executive Vice President, Head of Sanofi Genzyme

New York - February 11, 2016

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Forward Looking Statements

This presentation contains forward-looking statements as defined in the Private Securities Litigation Reform Act of1995, as amended. Forward-looking statements are statements that are not historical facts. These statements includeprojections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions andexpectations with respect to future financial results, events, operations, services, product development and potential,and statements regarding future performance. Forward-looking statements are generally identified by the words"expects", "anticipates", "believes", "intends", "estimates", "plans" and similar expressions. Although Sanofi'smanagement believes that the expectations reflected in such forward-looking statements are reasonable, investors arecautioned that forward-looking information and statements are subject to various risks and uncertainties, many of whichare difficult to predict and generally beyond the control of Sanofi, that could cause actual results and developments todiffer materially from those expressed in, or implied or projected by, the forward-looking information and statements.These risks and uncertainties include among other things, the uncertainties inherent in research and development,future clinical data and analysis, including post marketing, decisions by regulatory authorities, such as the FDA or theEMA, regarding whether and when to approve any drug, device or biological application that may be filed for any suchproduct candidates as well as their decisions regarding labeling and other matters that could affect the availability orcommercial potential of such product candidates, the absence of guarantee that the product candidates if approved willbe commercially successful, the future approval and commercial success of therapeutic alternatives, the Group's abilityto benefit from external growth opportunities, trends in exchange rates and prevailing interest rates, the impact of costcontainment initiatives and subsequent changes thereto, the average number of shares outstanding as well as thosediscussed or identified in the public filings with the SEC and the AMF made by Sanofi, including those listed under"Risk Factors" and "Cautionary Statement Regarding Forward-Looking Statements" in Sanofi's annual report on Form20-F for the year ended December 31, 2014. Other than as required by applicable law, Sanofi does not undertake anyobligation to update or revise any forward-looking information or statements.

Key Accomplishments Since April 2015On Our Way to Future Success

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(1) LixiLan (U.S.), sarilumab (U.S.) and lixisenatide (U.S.)(2) BioNTech, Evotec, Hanmi, Innate Pharma, Lexicon Pharmaceuticals, Regeneron and Verily (formerly Google Life Sciences), (3) December 15, 2015 press release: Sanofi and Boehringer Ingelheim enter exclusive negotiations on business swap: subject to

execution of a definitive agreement and regulatory approvals, Sanofi would become a global leader in Consumer Healthcare and Boehringer Ingelheim would become second largest Animal Health companyIcons designed by Freepik

3 launches of major products – Toujeo®, Praluent® and Dengvaxia®

3 submissions for regulatory review(1)

Significant R&D alliances in oncology and diabetes(2)

Key first transaction announced to reshape the portfolio(3)

New organizational model in place to drive focus and simplification

2020 strategic roadmap to create long term value

● Multiple Sclerosis(1)

● Oncology(1)

● Immunology(1)

● Consumer Healthcare(2)

● Animal Health

● Generics(2)

in Europe

● Diabetes/CV

● Vaccines

● Rare Diseases(1)

● Emerging Markets(2)

Specialty Care Global Business Unit

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Explore strategic options

Sustain leadership

Build competitive positions

(1) Will be part of Sanofi Genzyme Specialty Care Global Business Unit(2) Will be part of General Medicines and Emerging Markets Global Business Unit

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● Strong historic growth: >25% per year over 2012-2015

● Leading position in Rare Diseases

● Growing presence in Multiple Sclerosis

● Around 10% of Sanofi sales(1)

● Proven ability to execute in specialized disease areas

● Historic supply chain issues successfully addressed

(1) Calculated using FY 2015 sales

Delivered Strong Growth in 2015

€1.1bn

€3.7bn

2015

€1,785m

€2.6bn

2014

€2,604m

2013

€2,142m

2012

MultipleSclerosis

RareDiseases

+24.3%Growthat CER +25.9%+16.9%

Annual Sales

+29.5%

2013 2014 2015

Other

New Patient Accrual Continues to Drive Double Digit Growth in Rare Diseases

Rare Diseases Sales

€2,550m+11.4% at CER

€2,137m+11.2% at CER

€1,974m

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&

(1) Excluding Russia purchase pattern Gaucher franchise grew by +10.8% at CER(2) Four rolling quarters from Q4 2014 through Q3 2015(3) Modified recombinant human GAA (acid alpha-glucosidase) harboring synthetic oligosaccharide ligands

● Gaucher franchise grew +8.6% at CER(1)

● Optimize launch of Cerdelga®

● Apply proven screening protocols with hematologists

● Fabry franchise grew +17.2% at CER● Focus primarily on nephrologists and family

tree mapping to identify new patients● Develop oral GCS Inhibitor

● Pompe franchise grew +12.4% at CER● Test for high risk patients in neurology and

neuromuscular specialty areas● Develop neo-GAA(3)

Sustaining Leadership in Rare Diseases

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● Sustain market share through patient-centered approach, product differentiation and market access

● Grow market through patient screening and manufacturing expansion

● Advance internal and partnered novel pipeline

Sales CAGR for Rare Diseases expected at high single digit at CER over 2015-2020

1

2

3

Undiagnosed(1) Undiagnosed(1)

Undiagnosed(1)

(1) Genzyme internal analysis. Include China and India

● Acid sphingomyelinase deficiency (ASMD), also known as Niemann-Pick Type B, is a lysosomal storage disorder, characterized by fat deposits in spleen and liver

● Patient identification uses established diagnosis algorithm for Gaucher

● ASMD diagnosis rate in the low to mid-single digits after testing negative for Gaucher

Gaucher Hematology Campaign

ASMD Patient Diagnosis

Olipudase alfa – An Investigational Treatment for ASMD with FDA Breakthrough Therapy Designation(1,2)

Therapeutic Approach

Phosphorylcholine Ceramide

Sphingosine

Acid-Ceramidase

Intended result:Reverse and prevent somatic disease

if treatment begins early

Target the underlying metabolic defectby replacing the missing enzyme

Olipudasealfa

Olipudasealfa

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Sphingomyelin

(1) Olipudase alfa is the recombinant form of human acid sphingomyelinase currently being developed as an enzyme replacement therapy (ERT).(2) The Breakthrough Therapy designation is supported by data from a completed Phase 1b study. The data on repeat-dose safety, pharmacodynamics,

and exploratory efficacy support continued development for the investigational use in nonneurological manifestations of ASMD.

Pivotal Phase II/III trial expected to start in Q2 2016

Collaboration Provides Access to Unique RNAi Opportunities

● ~50,000 patients worldwide● FAP and FAC are the two predominant forms● Liver transplantation is often required early and

TTR stabilizers provide modest benefit

● Autosomal dominant with >100 defined mutations● Misfolds and forms amyloid deposits in nerves, heart,

other tissues

Progressive, debilitating monogenic

disease

Mutant transthyretin (TTR)

is genetic cause

RNAiis a potentially transformative

therapy

● Knockdown disease causing protein● Aim to halt progression, possibly achieve regression

Transthyretin-Mediated Amyloidosis (ATTR) Program

FAP: Familial amyloidotic polyneurapthyFAC: Familial amyloidotic cardiomyopathy 9

Patisiran: Familial AmyloidoticPolyneuropathy

Patisiran: an Investigational IV Administered RNAiTherapeutic to Treat the FAP Form of ATTR

● Positive Phase II results in FAP

● Statistically significant, dose dependent TTR knockdown of up to 96%(1)

● Phase II Open-Label Extension (OLE) ongoing

● APOLLO Phase III trial ongoing

● FDA submission targeted for late 2017

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Dose Response and Durationof TTR Knockdown

Patisiran is developed in collaboration with AlnylamFAP: Familial amyloidotic polyneurapthy; ATTR: Transthyretin (TTR)-mediated amyloidosis(1) Minimal drug-related adverse events reported in FAP patients out to nearly two years. The most common drug-related or possibly drug-related

adverse events were flushing (25.9%) and infusion-related reactions (18.5%), which were both mild in severity and did not result in any discontinuations.

(2) Excludes post-day 28 data from one patient that experienced drug extravasation during second infusion

% Mean Serum TTR KnockdownRelative to Baseline (SEM) - n=29

Days Since First Visit

Cohort 0.30 mg/kg q3w

Cohorts 0.01-0.30 mg/kg q4w

Patisiran Treatment Groups

0.01 mg/kg q4w (n=4)0.05 mg/kg q4w (n=3)0.15 mg/kg q4w (n=3)0.30 mg/kg q4w (n=6)(2)

0.30 mg/kg q3w (n=12)

Revusiran: Familial AmyloidoticCardiomyopathy

● Positive Phase II results in TTR cardiac amyloidosis patients(1)

● Phase II Open Label Extension (OLE) ongoing

● Subcutaneous administration

● Phase III ENDEAVOUR trial ongoing with data expected in 2018

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Rapid, Dose-dependent, Consistent, Durable Knockdown of Serum TTR of Up to 98% in Phase II(2)

Revusiran: an Investigational Subcutaneously Administered RNAi Therapeutic to Treat the FAC Form of ATTR

Revusiran is developed in collaboration with AlnylamFAC: Familial amyloidotic cardiomyopathy; ATTR: Transthyretin (TTR)-mediated amyloidosis(1) Serious adverse events (SAEs) were observed in 8 patients (32%), including one death due to infiltrative cardiomyopathy; none of the SAEs were

deemed to be related to study drug. The majority of the adverse events (AEs) were mild or moderate in severity; injection site reactions (ISRs) were reported in 11 patients (44%). As previously reported, 3 patients discontinued due to recurrent localized reactions at the injection site or a diffuse rash; no further discontinuations due to ISRs have occurred

(2) Based on the enrollment of 26 patients, including 12 patients with senile systemic amyloidosis (SSA) and 14 patients with FAC

● Antithrombin (AT) is a key endogenous anticoagulant● Inactivates Factor Xa and thrombin

● Attenuates thrombin generation

● Expressed in liver; circulates in plasma

● Human AT deficiency associated with increased thrombin generation

● Subcutaneous fitusiran aimed at correcting coagulation defects by knockdown of AT● Currently in Phase I in

moderate-to-severe hemophilia

Fitusiran (ALN-AT3): an Investigational RNAiTherapeutic Targeting Antithrombin

ATFIX

FVIII

FIXa

FVIIa FVIIFVIIIa

FVa FV

FX

FXa

Fibrinogen Fibrin

ThrombinProthrombin

Blood clot

Intrinsic system Extrinsic system

Hemophilia B

Hemophilia A

FVIII

FIXAT

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Coagulation Cascade

Phase III planned to start in Q3 2016

Fitusiran is developed in collaboration with Alnylam

2013 2014 2015

Multiple Sclerosis Franchise Sales Doubled to Over €1bn

● Aubagio® sales up +77.8% at CER● Fastest growing oral MS drug in the U.S.

in 2015(1)

● U.S. weekly TRx share of 6.6%(1)

● Now Genzyme’s #1 product in sales

● Lemtrada® sales reached €243m in 2015, up from €34m in 2014● Western Europe sales tripled● 53% of sales generated in the U.S.

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Multiple Sclerosis Sales

€1,114m+112% at CER

€871m+77.8%at CER

€243m

€467m+178% at CER

€168m

(1) IMS U.S. TRx for week ending January 15, 2016

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A Successful New Global Campaign

● Approved in more than 50 countries

● >40,000 people treated with Aubagio®

worldwide

● Only oral MS treatment to significantly reduce the risk of SAD in 2 Phase III studies in RMS(1) (TEMSO and TOWER)

● Positive data in early MS(2) (TOPIC)

● New analysis of MRI data showing significant reductions in brain volume loss

● Favorable tolerability, once daily dosing

SAD: sustained accumulation of disability (1) AUBAGIO® (teriflunomide) is effective across key measures of disease activity: sustained disability

progression (14 mg only), annualized relapse rate, and MRI activity. Common side effects with AUBAGIO led to treatment discontinuation rates ≤3.3% in clinical trials.

(2) Patients with a first clinical event consistent with MS

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Potential to Transform MS Patients’ Lives

● Approved in more than 40 countries

● Extensive clinical development program with 5,400 patient-years of follow-up

● Durable improvements in relapse, disability, and MRI outcomes over 5 years in active RRMS demonstrated in CARE-MS I and II extension studies

No retreatment with Lemtrada® after the initial 2 courses in the core studies for most patients through Year 5

(1) The most common side effects of Lemtrada® are rash, headache, thyroid disorder, pyrexia, nasopharyngitis, nausea, urinary tract infection, fatigue, insomnia, upper respiratory tract infection, herpes viral infection, urticaria, pruritus, fungal infection, arthralgia, pain in extremity, back pain, diarrhea, sinusitis, oropharyngeal pain, paresthesia, dizziness, abdominal pain, flushing, and vomiting. Other serious side effects associated with Lemtrada® include autoimmune thyroid disease, autoimmune cytopenias, infections and pneumonitis.

(2) Label includes a boxed warning noting a risk of serious, sometimes fatal autoimmune conditions, serious and lifethreateninginfusion reactions and noting Lemtrada® may cause an increased risk of malignancies including thyroid cancer, melanoma and lymphoproliferative disorders. Lemtrada® is contraindicated in patients with HlV infection.

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Strategy to Grow the Multiple Sclerosis Franchise

● Successfully complete global launches of Aubagio® and Lemtrada®

● Expand LCM activities to maximally support existing products

● Develop Lemtrada® for subcutaneous use

● Run a PoC study in Progressive MS with Lemtrada®

● Reinforce presence in “high efficacy” category

● Advance GLD52, a next generation anti-CD52 mAb, through Phase I

● Enter into the neuroprotection / remyelination segment

● Eight programs currently in research

Ambition to double the size of the MS franchise sales from 2015 to 2020 to >€2bn

LCM: Life Cycle Management

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2

3

4

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Immuno-Modulationis at the core of

Sanofi’s R&D strategy

RheumatoidArthritis

AsthmaAtopic Dermatitis

InflammatoryBowel Disease Systemic

Lupus Erythematosus

Immunology is a New Growth Engine for Sanofi

Positioning Sarilumab for Potential Success in theRheumatoid Arthritis Biologic Market(1)

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Sarilumab is developed in collaboration with Regeneron(1) Sarilumab is an investigational agent under clinical development and its safety and efficacy has not been fully

evaluated by any Regulatory Authority(2) Two subcutaneous dosing options- 200 mg and 150 mg, every other week - for all patients (not weight based)(3) X-ray data demonstrating 90% inhibition of structural damage with 200 mg every 2 weeks SC dosing(4) Humira® (adalimumab) is an AbbVie brand(5) Biologics License Application submitted to the FDA in October 2015

● IL-6 plays key roles in the local joint symptoms and systemic manifestations of rheumatoid arthritis (RA)

● Entering an €18bn RA market where unmet need is still high● IL-6 class >€1bn in sales and growing >20%● Unique profile features potential dosing flexibility(2) and

impact on bone erosion(3)

● Positive Phase 3 data in methotrexate-inadequate responder (IR) and difficult-to-treat TNF-IR populations● Phase 3 MONARCH monotherapy study vs. Humira®

results expected in Q2 2016(4)

● U.S. regulatory decision expected in Q4 2016(5)

● E.U. submission anticipated in Q3 2016

MOBILITY: Sarilumab Inhibited Progression of Structural Damage

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Sarilumab is developed in collaboration with Regeneron*p<0.0001, **p=0.003(1) Change from Baseline in mTSS (Van der Heijde modified Total Sharp Score)(2) In the MOBILITY study, infections were the most frequently reported adverse events and were reported with a higher incidence in the sarilumab

groups vs. placebo, all in combination with MTX (39.6% for 200 mg, 40.1% for the 150 mg group and 31.1% for pbo). The incidence of serious infections was 4.0% in the 200 mg + MTX group, 2.6% in the 150 mg + MTX group, and 2.3% in the placebo + MTX group.

(3) Incidence ≥3%Q2W = every other week; SC = subcutaneous

0

1

2

3

0 4 8 12 16 20 24 28 32 36 40 44 48 52

90%

*

*

70%

Placebo + MTX

sarilumab 150 mg q2w + MTX

sarilumab 200 mg q2w + MTX

**

*

● X-ray data(1) demonstrating 90% inhibition of progression of structural damage with 200 mg Q2W SC dosing

● Safety profile consistent with mechanism of action(2)

● Most common adverse events(3)

included neutropenia, increased ALT, and upper respiratory infections

Change from Baseline in mTSSat Week 24 and Week 52

Fully Human IL-4Rα mAb TargetingIntracellular Signaling of Both IL-4 and IL-13

Dupilumab – A Pipeline in a Product withMulti-blockbuster Potential(1)

Dupilumab is developed in collaboration with RegeneronTh2: T-helper 2 cells involved in “humoral-mediated” immunity(1) Dupilumab is an investigational agent under clinical development and its safety and efficacy have not been fully evaluated by any regulatory agency 20

IL‐4

IL‐4R c

Type IReceptor

Type IIReceptor

IL‐13

IL‐4R IL‐13R1

or

IL-4/IL-13 pathway may be a fundamental driver in these Th2-mediated allergic diseases

Atopic Dermatitis● Received “Breakthrough Therapy” designation by FDA● SOLO 1 and 2 Phase III top line results expected in Q1 2016● CHRONOS Phase III interim results expected in Q2 2016● U.S. regulatory submission expected in Q3 2016

Asthma● Phase III ongoing● Completed Phase 2b trial considered pivotal by FDA

Nasal Polyposis● Start of Phase III expected in Q4 2016

Eosinophilic Esophagitis● Phase II ongoing

● Over 5 million people in the U.S. and EU(1) estimated to be affected by moderate-to-severe atopic dermatitis ● 40% of moderate-to-severe patients

uncontrolled with topicals

● Characterized by eczematous dermatitis with intractable pruritus

● Negative impact on Quality of Life is underestimated● Similar or higher than in psoriasis● Greater risk for psychological distress

including anxiety, depression and suicidal ideation(2,3,4)

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Atopic Dermatitis Is a Serious, Chronic, Inflammatory Skin Condition

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(1) Adapted from White Book on Allergy published in 2011, http://www.worldallergy.org/UserFiles/file/WAO-White-Book-on-Allergy_web.pdf(2) Journal of Psychomatic Research 57 (2004) 195-200(3) Acta Derm Venereol 2004;84(3):205-12(4) Suicide Life Threat Behav 2006 2006 Feb;36(1):120-4

Parameter Placebo 300mg q2w 300mg qw

EASI Score 18% 68.2% 73.7%50/75/90 EASI Improvement 29.5%/11.5%/3.3% 78.1%/53.1%/29.7% 82.5%/60.3%/36.5%

IGA Response 1.6% 29.7% 33.3%

Pruritus NRS 11.4% 52.9% 59.7%5-D Pruritus

Score 8.2% 35.4% 43.6%

Dupilumab is developed in collaboration with Regeneron(1) Mean percent change in EASI (Eczema Area Severity Index)(2) Proportion of patients achieving EASI-50/70/90 (3) Proportion of patients achieving IGA ≤ 1 (Investigator’s Global Assessment score of 0 “clear” or 1 “almost clear”)(4) Mean percent change in pruritus NRS (Numeric Rating Scale) weekly averaged (5) Mean percent change 5-D Pruritus Score

Dupilumab Significantly Improved Signs and Symptoms in Moderate-to-Severe AD Patients Uncontrolled by Topicals

300mg qw and 300mg q2w dose regimens being studied in Phase 3 program

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p<0.0001 vs placebo for all parameters

Phase IIb Study in AD - Change in Efficacy Endpoints at 16 Weeks(1-5)

Primary endpoint of Phase 3 studies

Dupilumab Safety Findings in Moderate-to-SevereAtopic Dermatitis

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21%

PlaceboDupilumab

23%

18.5%

Nasopharyngitis

8%

PlaceboDupilumab

15%

12%

Headache

3%

Dupilumab Placebo

9.5%

5%

Injection site reactions

● Nasopharyngitis, the most common adverse event, balanced across dupilumabtreatment groups vs. placebo

● Headache and injection site reactions more frequent with dupilumab

Ongoing follow-up period of 16 weeks after treatment

Phase IIb Study

Dupilumab is developed in collaboration with Regeneron

● 235-300m people worldwide estimated to be affected by asthma(1)

● ~25m people in the U.S. alone● 10 to 20% of patients uncontrolled despite

existing therapies

● Chronic inflammatory disease leading to acute and chronic narrowing of the airway and increased mucus production

● Patients with asthma experience wheezing, shortness of breath, cough and chest tightness

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Moderate-to-Severe Asthma Negatively Impacts the Lives of Patients and Is Associated with High Burden to Society

24(1) WHO, http://www.who.int/mediacentre/factsheets/fs307/en/

Dupilumab Shows Improvement in Lung Functionin Phase IIb in Moderate-to-Severe Asthma

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Dupilumab is developed in collaboration with RegeneronFEV1=forced expiratory volume over one second During the treatment period, patients continue their stable medium- or high-dose inhaled corticosteroid and long-acting beta agonist (ICS/LABA) combination productThis result was based on a pre-specified interim analysis, which occurred when all patients had reached Week 12 of the 24-week treatment period

0

100

200

300

400

500

High Eosinophils Population Overall population

Placebo200mg Q2W300mg Q2W

10.4%

25.9%(1)

25.8%(2)

mL

18.0%(1)

17.7%(1)

6.2%

(1) p<0.001 vs placebo

(2) p<0.01 vs placebo

Phase IIb - Mean Improvement in FEV1(mL and % Change from Baseline)

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Dupilumab Shows a 64-75% Reduction in Exacerbations in Phase IIb in Moderate-to-Severe Asthma

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

High Eosinophils Population Overall population

Placebo200mg Q2W300mg Q2W

Dupilumab is developed in collaboration with RegeneronDuring the treatment period, patients continue their stable medium- or high-dose inhaled corticosteroid and long-acting beta agonist (ICS/LABA) combination productThis result was based on a pre-specified interim analysis, which occurred when all patients had reached Week 12 of the 24-week treatment period

-75%(1)

-64%(1) -67%(2)

-67%(3)

(1) p<0.05 vs placebo

(2) p<0.01 vs placebo

(3) p<0.001 vs placebo

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Phase IIb - Annualized Rate of Severe Exacerbation Events

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Dupilumab Safety Profile in Moderate-to-Severe Asthma

46%

PlaceboDupilumab

45%42%

Infections

5%

PlaceboDupilumab

7%

3%

Severe AEs

12%

Dupilumab Placebo

25%

13%

Injection site reactions

● Injection site reaction was the most common adverse event and was more frequent with dupilumab● Other common adverse events in the study included upper respiratory tract infection, headache,

nasopharyngitis and bronchitis● Incidence of infections of serious adverse events was balanced across treatment groups

Phase IIb Study

Dupilumab is developed in collaboration with Regeneron

Four Strategic Priorities

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Reshapethe portfolio

Deliver outstanding

launches

Simplify the organization

Sustaininnovation

in R&D

1 2 3

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Taking our Strategy Forward in 2016