Deutsche Bank Healthcare ConferenceDavid P. Meeker, Chief Executive Officer, Genzyme

Boston, May 7, 2014

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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 policies 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, 2013. Other than as required by applicable law, Sanofi does not undertake anyobligation to update or revise any forward-looking information or statements.

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Sanofi Highlights to Date

Rare Disease Opportunity

Agenda

Multiple Sclerosis Opportunity

Key Highlights for Q1 2014

Top and bottom line growth in line with expectations– Net sales up +3.5% at CER– Business EPS up +5.8% at CER

New product launches – Nasacort® Allergy 24HR nasal spray in the U.S.– NexGard™ chewables in the U.S.

Late stage R&D pipeline progress– Dengue vaccine met primary endpoint in 1st Phase III study – Significant advances with Lemtrada™, alirocumab, LixiLan, dupilumab

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Increased value of open innovation– Strengthened collaborations with Regeneron and Alnylam– New collaborations with UCB and SK Chemical

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2

3

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Q1 2014

-€0.11

FX ImpactIncremental EPS at CER

Q1 2013

+€0.07

Net Sales Business EPS

Sanofi Delivered Top and Bottom Line Growth at CER, in Line with Expectations

5(1) On a reported basis, Q1 2014 sales were down -2.7% and Business EPS was down -3.3%(2) With retroactive application of IFRIC21

+5.8% at CER(1)

Incremental Sales at CER

Q1 2014Q1 2013 FX Impact

+€280m-€497m

+3.5%at CER(1)

€8,059m€7,842m

€1.21€1.17

(2)

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(1) World excluding U.S., Canada, Western Europe (France, Germany, UK, Italy, Spain, Greece, Cyprus, Malta, Belgium, Luxembourg, Portugal, Holland, Austria, Switzerland, Sweden, Ireland, Finland, Norway, Iceland, Denmark), Japan, Australia, and New Zealand

(2) Western Europe: France, Germany, UK, Italy, Spain, Greece, Cyprus, Malta, Belgium, Luxembourg, Portugal, Holland, Austria, Switzerland, Sweden, Ireland, Finland, Norway, Iceland, Denmark

Q1 2014 Net Sales

(1)

(2)

Latin America: +13.1% at CERAsia: +4.0% at CEREastern EU, Russia & Turkey: +4.0% at CERMiddle East & Africa: -1.0% at CER

€2,590m+5.5% at CER

€2,415m+7.5% at CER

€1,998m-0.3% at CER

€839m-4.0% at CER

Continued Solid Growth in Two Largest Geographies

Emerging Markets

United States

Western EU

RoW

+18.6%+18.6%Consumer Healthcare (1) €885m

Vaccines -4.2%-4.2%€628m

Genzyme(2)

Growth Platforms Grew by +7.9% Reaching 73.7% of Sales

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(1) Some products recorded in prescription pharmaceuticals in Q1 2013 were transferred as Consumer Healthcare products and totaled €68m in Q1 2014. Excluding this change of perimeter, sales of Consumer Healthcare grew 9.4% in Q1 2014.

(2) Genzyme perimeter includes Rare Diseases and Multiple Sclerosis franchises(3) Includes products launched since 2009 which do not belong to the Growth Platforms listed above: Multaq®, Jevtana®, Auvi-Q™,

Mozobil® and Zaltrap®

+13.2% +13.2%

-4.2%-4.2%

+21.5%+21.5%

-1.6% -1.6%

Other Innovative Products(3) €190m +22.6%+22.6%

+5.5%+5.5%

Diabetes Solutions €1,662m

Animal Health

€566m

Emerging Markets €2,590m

€517m

Q1 2014Growth at CER

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Sanofi Highlights to Date

Rare Disease Opportunity

Agenda

Multiple Sclerosis Opportunity

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Orphan Drug Market

Orphan Drug Market is Attractive and Offers Growth Potential Due to Significant Unmet Needs

● Significant unmet needs create strong growth potential● Under-served patient population

● Drugs available for only ~300 out of >7,000 orphan diseases(1)

● 85% orphan diseases are life threatening and 50% are pediatric(2)

● Several attractive market characteristics ● Unique development challenges

● Regulatory exclusivity period

● >$80bn sales for orphan-only drugs growing at high single digits(3)

● Expected CAGR 2012-2018 +7.4%

(1) National Organization for Rare Disorders 2013(2) Food and Drug Administration, "Office of Orphan Products Development," Budget 2010(3) EvaluatePharma Orphan Drug Report 2013

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Creation of the Genzyme

R&D Center

Leveraging Genzyme’s Innovative Capabilities

● Strong expertise in rare disease and multiple sclerosis

● Unique biologics platform

● Commitment to open innovation

● Integrated innovation hub in the Boston area

Top 3 Rare Disease Products Sales

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Genzyme Rare Disease Products Lead the Market

● Q1 2014 Rare Disease sales of €483m, up +8.5% at CER

● Leadership positions● Cerezyme®: #1 therapy for Gaucher(1)

● Fabrazyme®: #1 position(1) reached in just four quarters once supply restored

● Myozyme®: the only approved therapy for Pompe

● Committed to developing new therapies● Next generation ERT for Pompe and new

oral therapy for Fabry now in Phase I● Expanded collaboration with Alnylam

(1) Cerezyme® value share is 73% and Fabrazyme® value share is 54% based on Q1 2014 reported sales by Sanofi and Shire

&

Q1 2014Q1 2013 Q1 2014Q1 2013 Q1 2014Q1 2013

€98m

€121m

€168m

+13.0%at CER

+7.8%at CER

+5.8%at CER

ERT: Enzyme Replacement Therapy

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1983

2001

Cerezym Is the Foundation of the Genzyme Model

Transformative Therapy

Q1 2014 Sales Split

Ensure Market AccessExtensive Global Reach

● Increase awareness

● Enable access to diagnostic testing

● Identify and train experts

● Support patient advocacy

● Partner with healthcare systems

EU

U.S.ROW

35%

38%27%

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(1) Cerezyme® value share is 73% based on Q1 2014 reported sales by Sanofi and Shire(2) Sims K, Pastores G, Weinreb N, Barranger J, Rosenbloom B, Packman S, et al. Improvement of bone disease by

imiglucerase (Cerezyme®) therapy in patients with skeletal manifestations of type 1 Gaucher disease: results of a 48-month longitudinal cohort study. Clin Genet 2008; 73:430-40

(3) Symptomatic prevalence and diagnosed patient estimates from 2010 PGH Market Models / Epidemiology Database

● Cerezyme® maintained #1 market position with Q1 2014 sales up +5.8%(1) to €168m

● Gold-standard product:● 20 years of proven safety and

efficacy ● Demonstrated improvement in bone

symptoms(2)

● Currently treating ~5,000 patients

● Investigational next generation oral product under review by EU and U.S. regulatory authorities

Treating Gaucher Disease for Over 20 years

Total treatedDiagnosed

~8,800 ~7,200

CZ treated

~5,000

Large population of undiagnosed patients(3) 9% of

diagnosed patients not treated

Gaucher Disease

ENGAGE - Change in Spleen Volume

A Novel Investigational Oral Therapy to Expand Genzyme’s Gaucher Franchise

● Oral therapy providing an alternative to infusion challenges

● Largest ever clinical program in Gaucher: ~400 adults in 29 countries● Phase III studies included patients just

starting treatment (ENGAGE) and patients switching from ERT (ENCORE)

● All primary/secondary endpoints met in Phase III studies

● Non-inferiority criteria to Cerezyme® met (ENCORE)

● Ongoing regulatory review by EMA and FDA● Priority review granted in the U.S.● Expect decisions in H2 2014

ERT: Enzyme Replacement Therapy

+2%

-28%

Placebo

Eliglustat

30%Absolute Difference

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Potential to grow market and expand Genzyme share

p<0.0001

% Change at 9 Months

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Demonstrating Strong Recovery

● Fabrazyme® sales grew 13.0% to €98m in Q1 2014(1)

● Regained leading position(2) by:● Restoring supply

● Driving importance of dose outcomes in clinical trials

● Currently treating ~2,900 patients

● Investigational next generation oral therapy for Fabry now in Phase I

(1) Growth is at constant exchange rates and at comparable perimeter (2) Fabrazyme® value share is 54% based on Q1 2014 reported sales by Sanofi and Shire(3) Symptomatic prevalence and diagnosed patient estimates from 2010 PGH Market Models / Epidemiology Database

Total treated

~5,500

FZ treated

~6,500

Diagnosed

Large population of undiagnosed patients(3)

~30% of diagnosed patients not treated

~2,900

Fabry Disease

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Fabrazyme – Treating the Family

Finding 1 new index patient leads, on average, to diagnosis of another 5 patients in that family

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Only Approved Treatments for Pompe Disease

● Myozyme® grew +7.8% to €121m in Q1 2014(1)

● Long-term potential commercial opportunities similar to Cerezyme®

● Focus is on:● Driving disease awareness

● Partnering with physicians to increase early diagnosis

● Currently treating ~2,000 patients

● Investigational next generation ERT for Pompe disease now in Phase I

ERT: Enzyme Replacement Therapy(1) Growth is at constant exchange rates and at comparable perimeter (2) Symptomatic Prevalence based on 2011 Pompe Epi Model in 92 countries (excluding China and India)

MZ/LZ treated

~2,000

Total treated

~2,000

Diagnosed

~2,600

Large population of undiagnosed patients(2)

19% of diagnosed patients not treated

Pompe Disease

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Genzyme’s Leadership in Rare Diseases Increases through Expansion of Alnylam Collaboration

(1) Proprietary technology that conjugates a sugar molecule called “GalNAc” to the siRNA (small interfering RNA) (2) In January 2014, Genzyme purchased $700m of Alnylam common stock. On March 25, 2014, Genzyme exercised its right to

purchase additional shares of Alnylam for $23m as a result of Alnylam’s issuance of shares to Merck in connection with the acquisition of Sirna Therapeutics. The exercise of this right to purchase the maximum number of additional shares under the terms of the investor rights agreement allows Genzyme to maintain its current ownership level of Alnylam common stock of approximately 12%.

● Alnylam’s RNAi technology to provide a platform for sustained drug development for rare genetic diseases for Genzyme

● Focus is on genetically defined diseases with a clear translational model for RNAi

● Delivery platform enabling subcutaneous administration of drug candidates targeting hepatocytes(1)

● Genzyme now one of Alnylam’s main shareholders with 12% stake(2)

PC P1 P2 P3

Patisiran (TTR‐FAP) in expanded territory

AS1 (Hepatic Porphyria)

TTRsc (FAC)

Unnamed

AT3 (Hemophilia)

TTR-FAP: Transthyretin-Familial Amyloïd PolyneuropathyFAC: Familial Amyloïd Cardiomyopathy

Program Rights*

*subject to opt-in

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Sanofi Highlights to Date

Rare Disease Opportunity

Agenda

Multiple Sclerosis Opportunity

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Global MS Market - Significant and Growing Market

● Multiple Sclerosis is a serious disease with significant unmet medical needs

● Symptoms include fatigue, weakness, walking and balance difficulties, vision problems

● A major impact on family, social and professional life

● ~2.1m patients worldwide(1)

● ~410,000 patients in the U.S.(1)

● ~630,000 patients in EU(2)

(1) National Multiple Sclerosis Society(2) http://msj.sagepub.com/content/18/5/628.full.pdf(3) Adapted from Evaluate Pharma July 2013; Reported sales of Copaxone®, Avonex®, Rebif®, Betaseron/Betaferon®, Extavia®,

Tysabri® and Gilenya® for 2012; 2007 sales converted using €/$ of 1.37, 2012 sales and 2017e sales converted using €/$ of 1.29

2012

2017e

U.S.ROW

~€11bn

>€14bn

2007

~€5bn

~40% ~60%

2012-17 growth driven by new therapies, satisfying the unmet needs of convenient administration and more efficacious therapy

~50% ~50%

Multiple Sclerosis Market Global Sales(3)

MS Market in a State of Transition Presents Opportunities

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Multiple Sclerosis Market Features

Today

● 7 Mechanisms of Action

● 10 Marketed Products

● 3 Modes of Administration

● Greater Treatment Urgency

In 2005

● 2 Mechanisms of Action

● 4 Marketed Products

● 1 Mode of Administration

● More Acceptance of Disease Activity

Increasing diversity of therapeutic options allowing a more individualized treatment approach

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● Oral therapy(2) share projected to increase to nearly 48% of the MS market by 2018 driven by new entrants

● Intravenous therapies(3) expected to approach 20% of the market

● Injectable therapies(4) (ABCRE’s) projected to decline by roughly half of current usage by 2018

(1) Evaluate Pharma December 2013 (2) Oral category includes Aubagio®, Gilenya®, Tecfidera®, laquinimod, 2nd Gen S1Ps(3) Intravenous category includes Tysabri®, Lemtrada®, ocrelizumab, daclizumab(4) Injectable category includes Avonex®, Betaseron/Betaferon®, Copaxone®, Rebif®, Extavia®, Plegridy™

Transition to Oral and Intravenous TherapiesExpected to Continue

59%

MS Market Evolution(1,2,3,4)

(% market share)

60%

90%

45%

15%

75%

30%

0%

2012

Injectables

Intravenous

2018e

Orals

23(1) New Active Substance (NAS) status granted in Europe in Jun 2013

Encouraging Launch Trends with Strong Patient Demand

● Q1 2014 sales of €78m ● Approved in the U.S. and EU(1)

● Additional approvals include Australia, Switzerland, Argentina and Canada

● EU launch rollout started in Q4 2013● Strong launch in Germany, Switzerland

and Nordic countries

● ~1/3 of patients switched to Aubagio®

in the U.S. were most recently on another oral therapy

Aubagio® Quarterly Sales

Q1 2013 Q3 2013Q2 2013

€20m

€33m€44m

€69m

Q4 2013

€78m

Q1 2014

24(1) FY 2013 sales of €2m, Q1 2014 sales of €5m(2) FDA will assign a 2 month or 6 month review cycle within 14 calendar days of receipt of the resubmission

Lemtrada™ is developed in collaboration with Bayer HealthCare

Initial Global Launches Underway

● Regulatory approvals granted in EU, Australia, Brazil, Canada, and Mexico

● EU launch rollout started in Q4 2013(1)

● Complete response letter received from FDA in late Dec 2013● Planned sBLA resubmission in Q2 2014● FDA review timeframe: 2 or 6 months once filing is

accepted(2)

Genzyme’s Critical Success Factors in MS

Products People Approach

● Lemtrada™ and Aubagio®

are highly differentiated novel products

● Fulfill unmet needs

● Well positioned for an evolving market

● Accomplished team

● Leveraging experienced Sanofi MS sales reps in European countries

● Strong commitment and relationships

● Science driven and patient focused

● Long term partners

● Be leaders

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Launching a Global MS Franchise(1)

(1) Timing of regulatory approvals and country reimbursement policies may impact projected launch timelines

2012 Selected Markets 2014

2012 Selected Markets 2014

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Key Growth Drivers

● Maximize market opportunity for rare disease business

● Expected launch of eliglustat

● Investigational next generation therapies to address unmet needs

● Further expand rare disease business through internal andexternal opportunities

● Establish leading MS franchise

● Continue momentum of Aubagio® rollout(1)

● Expected FDA resubmission of Lemtrada™ in Q2 2014(2)

(1) Aubagio® was launched in U.S. and EU in 2013(2) FDA will assign a 2 month or 6 month review cycle within 14 calendar days of receipt of the resubmission

Multiple Regulatory and Phase III Development Milestones Are Expected in 2014

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2014Expected Regulatory Decisions Q1 Q2 Q3 Q4● Shan5® 5-in-1 pediatric vaccine WHO pre-qualification● Cerdelga™ in Gaucher disease (U.S. & EU)

● Lemtrada™ in Multiple Sclerosis (U.S.)

● Fluzone® QIV Intradermal (U.S.)

Expected Regulatory Submissions Q1 Q2 Q3 Q4● Fluzone® QIV Intradermal (U.S.)

● Lemtrada™ in Multiple Sclerosis (U.S.)

● Toujeo™ (U300) in Diabetes (U.S. & EU)

● 6-in-1 pediatric vaccine PR5i (U.S.)

● Alirocumab in Hypercholesterolemia (EU)

Expected Headline Phase III Data Releases Q1 Q2 Q3 Q4● Dengue vaccine 1st Phase III trial in Asia● Alirocumab in Hypercholesterolemia (multiple ODYSSEY trials)● Dengue vaccine 2nd Phase III trial in Latin America

Expected Phase III Starts Q1 Q2 Q3 Q4● LixiLan (lixisenatide + insulin glargine) in Diabetes● Dupilumab in Atopic Dermatitis

● Rotavirus vaccine

The Opportunity with Sanofi

Sanofi has transformed into a company positioned for sustainable growth through its Growth Platforms(1) and has a robust late-stage pipelineof new biologics

29(1) Growth Platforms include Emerging Markets, Diabetes Solutions, Vaccines, Consumer Healthcare, Animal Health, Genzyme

& Other Innovative Products. In Q1 2014, sales from Growth Platforms accounted for 73.7% of Group sales