PRESS RELEASE Paris

Sanofi delivers Q1 2015 Business EPS(1) growth of 2.6% at CER(2)

and 12.8% on a reported basis

Sanofi growth driven by Genzyme and Merial

Group sales(3) increased 2.4% (+12.3% on a reported basis) to 8,810 million

Slightly lower Diabetes sales (-3.2%) reflects expected pricing impact on Lantus in the U.S.

Genzyme delivered 30.9% growth mainly driven by Aubagio

Animal Health recorded a strong quarter (+13.5%) driven by performance of NexGard

Vaccines (-4.6%) declined due to expected delay in Southern Hemisphere influenza campaign

Emerging Markets(4) sales up 7.3%

Solid financial performance

Business net income(1) grew 1.6% at CER (up 11.6% on a reported basis) to 1,726 million despite launch investments and U.S. Lantus pricing impact

Business EPS(1) was up 2.6% at CER to 1.32 and increased 12.8% on a reported basis

Significant achievements with new product launches

Toujeo was launched in the U.S. and approved in EU

Cerdelga approved in Europe and in Japan

Lemtrada sales benefited from market introduction in the U.S.

Dengue vaccine rolling submission initiated in 6 endemic countries in Asia and Latin America

Results of ELIXA cardiovascular safety with lixisenatide support U.S. resubmission in Q3 2015

Further progress in R&D

Phase III study of dupilumab in moderate-to-severe asthma initiated

Phase IIb of the IL4/IL13 bi-specific mAb in idiopathic pulmonary fibrosis started

2015 financial guidance

Sanofi continues to expect 2015 Business EPS(1) to be stable to slightly growing versus 2014 at constant average exchange rates, barring major unforeseen adverse events(5)

In addition, the positive currency impact on 2015 full-year business EPS is estimated to be approximately +12%, under the assumption that exchange rates remain stable in the following three quarters at the average rates of March 2015

Sanofi Chief Executive Officer, Olivier Brandicourt commented:

Sanofi had a good start to 2015. Our businesses provide a solid foundation for our new-product cycle. Sanofi s recent launches along with the ongoing regulatory reviews and planned submissions before year-end will drive future growth. At this important time for the company, my primary focus will be on maximizing the value of this innovative product portfolio and further establishing Sanofi as a leading biopharmaceutical company.

(1) See Appendix 8 for definitions of financial indicators; (2) constant exchange rates; (3) Growth in net sales is expressed at constant exchange rates (CER) unless otherwise indicated (see Appendix 8 for a definition); (4) See page 8; (5) 2014 business EPS was 5.20

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2015 first-quarter figures

In order to facilitate an understanding of operational performance, Sanofi comments on the business net income statement. Business net income(1) is a non-GAAP financial measure. The consolidated income statement for Q1 2015 is provided in Appendix 4 and a reconciliation of business net income to consolidated net income in Appendix 3. Consolidated net income for Q1 2015 was 1,023 million compared to 1,084 million for Q1 2014. Consolidated EPS for Q1 2015 was 0.78 versus 0.82 for Q1 2014.

2015 first-quarter sales

Unless otherwise indicated, all sales growth figures in this press release are stated at constant exchange rates(1).

In the first quarter of 2015, Sanofi generated sales of 8,810 million, an increase of 12.3% on a reported basis. Exchange rate movements had a positive effect of 9.9 percentage points reflecting mainly the weakness of the Euro against the dollar. Other currencies impacting sales in the first quarter primarily included the Chinese Yuan on the positive side and the Russian ruble on the negative side.

Sales for the Pharmaceuticals business increased 2.2% to 7,455 million in the first quarter, driven mainly by Genzyme, CHC and established Rx products in Emerging Markets, which were partially offset by lower sales of Diabetes.

(1) See Appendix 8 for definitions of financial indicators.

In the first quarter, sales of the Diabetes division decreased 3.2% to 1,837 million. Sanofi recently managed to secure earlier and broader market access for Toujeo than expected due to a refined contracting strategy with payers in the U.S. As a result, Sanofi expects its global diabetes sales performance at constant exchange rates in the first quarter of 2015 to be indicative of the full year performance of this division.

Lantus sales were down 5.0% to 1,584 million over the period reflecting lower sales in the U.S., which were partially offset by strong growth in Emerging Markets. In the U.S., sales of Lantus were 1,007 million, a decrease of 13.1% due to the expected rebates required to maintain favorable formulary positions with key payers for contracts that started January 1, 2015. In Emerging Markets, Lantus sales were strong, up 18.0% to 276 million, reflecting solid growth in all regions. In Western Europe, Lantus first-quarter sales were up 6.3% to 223 million driven by growth in Germany, Portugal and Spain.

Toujeo , a next-generation basal insulin used to treat adults with type 1 and type 2 diabetes, was granted approval by the FDA in late February. Full launch activities in the U.S. market commenced at the end of March and included Toujeo COACH, a customized patient support program that offers tailored information and services for patients with diabetes. Sales of the product were 7 million in the first quarter which primarily reflected wholesaler demand in advance of the launch.

First-quarter sales of Amaryl were 97 million, up 1.2% sustained by Emerging Markets (+12.9% to 78 million), especially in Latin America and China.

Sales of Apidra increased 10.7% to 91 million in the first quarter driven by Emerging Markets (+31.3% to 22 million). In the U.S. and in Western Europe, sales were up 3.6% (to 35 million) and 8.7% (to 25 million), respectively.

First-quarter sales of Lyxumia were 8 million. Top-line results from the Phase IIIb ELIXA cardiovascular outcomes study of Lyxumia were announced in March and support the planned resubmission of the product in the U.S. in the third quarter of 2015.

Afrezza , a new rapid-acting inhaled insulin therapy (licensing agreement with MannKind), was launched in the U.S. in February 2015. Sales of the product were 1 million in the first quarter.

First-quarter sales of Consumer Healthcare products (CHC) were 979 million, an increase of 5.3% driven by Allegra and Enterogermina . Sales of CHC in Emerging Markets grew 6.3% to 455 million over the period led by Eastern Europe, particularly cough-and-cold products, and Latin America. In the U.S., first-quarter sales were up 5.5% to 259 million driven by Allegra which benefited from the launch of a new formulation. Sales of Nasacort were 42 million, a decrease of 16.7% impacted by an unfavorable comparison basis in the U.S. where the product was launched in the first quarter of 2014. Despite a price decrease of Doliprane in France in January 2015, CHC sales in Western Europe increased 0.5% to 202 million.

First-quarter sales of Genzyme increased 30.9% to 821 million reflecting the strong performance of Aubagio and double-digit growth of Rare Diseases products. Genzyme recorded double-digit sales growth in all territories including 37.7% to 357 million in the U.S., 24.2% to 244 million in Western Europe, 35.3% to 145 million in Emerging Markets and 20.7% to 75 million in the Rest of the World.

First-quarter sales of Rare Diseases reached 613 million, an increase of 15.9%.

Sales of the Gaucher franchise grew 10.1% to 199 million. Sales of Cerezyme were up 4.8% to 189 million in the first quarter, led by strong performance in Emerging Markets (up 16.4% to 66 million) especially in Latin America. Cerdelga , the only first-line oral therapy for Gaucher disease type 1 patients, was approved by the FDA in August 2014 and recorded sales of 10 million in the U.S.. The EMA approved Cerdelga for Gaucher disease type 1 patients in January 2015 and the product was launched in its first European market, Germany, in April. Cerdelga was also approved in Japan at the end of March.

First-quarter sales of Fabrazyme increased 27.6% to 141 million driven by strong growth in the U.S. (up 15.7% to 71 million), in Emerging Markets (up 157.1% to 19 million) and in Western Europe, (up 24.0% to 31million). In Emerging Markets, sales of the product benefited from a favorable phasing effect and the addition of new patients in Brazil.

Sales of Myozyme /Lumizyme grew 19.0% to 156 million in the first quarter, largely driven by an increase in worldwide diagnosis rates and patient identification leading to new patient accruals. In the U.S. (up 29.0% to 48 million) growth was partially due to the conversion of clinical study patients in 2014. Growth in Emerging Markets (up 36.8% to 28 million) also benefited from government ordering patterns in Brazil.

First-quarter sales of Multiple Sclerosis were 208 million (up 118.1%). Aubagio continued its success with sales more than doubling to 170 million versus 78 million in the same period of 2014. In the U.S., sales of Aubagio were 123 million versus 59 million in the first quarter of 2014. In Western Europe, sales were 36 million (versus 17 million in the same period of 2014) reflecting the continued roll out and successful launch in France.

First quarter sales of Lemtrada were 38 million including 18 million in Western Europe and 16 million in the U.S. where the product was introduced late last year.

Sales of Generics increased 10.2% to 478 million in the first quarter driven by the performance in Emerging Markets (up 12.7% to 277 million) led by cough-and-cold products in Eastern Europe and the performance in Latin America. In the U.S., sales of generics were up 17.9% to 41 million due to the growth of the authorized generics of Lovenox and Taxotere . In Western Europe, generics were down 2.9% to 138 million. In Rest of the World, sales more than doubled to 22 million, driven by Allegra generics sales in Japan.

First-quarter sales of Oncology were 357 million, a decrease of 7.3%, mainly reflecting lower sales of Taxotere .

Sales of Jevtana grew 7.6% to 77 million in the first quarter, led by the U.S. (up 15.0% to 27 million) and Japan where the product was launched in September 2014.

First-quarter sales of Thymoglobulin were 55 million, down 7.7%.

First-quarter sales of Taxotere decreased 31.9% ( 53 million), mainly due to generic competition. Over the same period, sales of Eloxatin increased 4.3% ( 54 million) driven by growth in China.

First-quarter sales of Mozobil were 34 million, up 20.0% driven by growth in the U.S. (up 15.4% to 18 million) and Emerging Markets (up 66.7% to 5 million).

In the first quarter, sales of Zaltrap grew 18.8% to 20 million, led by sales in Western Europe ( 13 million versus 7 million in the first quarter of 2014) which offset lower sales in the U.S.

Established Rx Products

Total sales of Established Rx Products were 2,983 million down 1.5%.

Sales of Plavix were down 9.4% to 483 million in the first quarter reflecting lower sales in Western Europe (down 30.6% to 44 million) due to generic competition and in Japan (down 12.6% to 198 million) impacted by an unfavorable comparison to the previous year resulting from buying patterns in anticipation of an increase in the consumption tax during the second quarter of 2014. In mid-2015, generic versions of Plavix are anticipated to enter the market in Japan. In Emerging Markets, sales of Plavix were 226 million, up 0.5% mainly due to lower sales in the Middle East. In China, sales of the product increased 4.4% to 142 million.

First-quarter sales of Lovenox were 438 million up 1.2%. In Emerging Markets, sales of the product grew 11.2% ( 157 million) led by growth in the Middle-East and Latin America, which was partially offset by lower sales in the U.S. (down 31.3% to 26 million) due to generic competition and stable sales in Western Europe ( 231 million).

Sales of Renvela /Renagel increased 13.4% to 226 million in the first quarter, driven by the U.S. (up 19.3% to 165 million). In the U.S., sales benefited from reduced competition from Impax which was granted a license to sell a limited number of bottles of an authorized generic version of Renvela tablets in the U.S. beginning in April 2014.

In the first quarter, sales of Aprovel /Avapro were stable at 201 million. The product recorded strong performance in Emerging Markets (up 18.7% to 125 million) driven by Latin America and China which was offset by lower sales in Western Europe (down 33.3% to 37 million) due to generic competition.

In the first quarter, consolidated sales of Sanofi Pasteur were 697 million, a decrease of 4.6% reflecting expected lower influenza vaccines sales due to the delay of the Southern Hemisphere influenza campaign which impacted the performance in Emerging Markets (down 19.4% to 228 million). Excluding influenza sales, the rest of the portfolio grew 17.2% in the first quarter. In the U.S., first-quarter sales increased 15.4% to 395 million driven by the continued recovery of Pentacel , the performance of Menactra and VaxServe (a Sanofi Pasteur company, U.S. specialty supplier of vaccines).

As the Southern Hemisphere influenza campaign was delayed by two required strain changes this year, first-quarter sales of Influenza vaccines were 22 million versus 135 million in the first quarter of 2014.

Sales of Polio/Pertussis/Hib vaccines were up 15.6% to 282 million in the first quarter. In the U.S., Polio/Pertussis/Hib vaccines sales increased 26.3% to 118 million, reflecting the continued recovery of Pentacel . In Emerging Markets sales of Polio/Pertussis/Hib vaccines grew 32.2% to 132 million led by strong performance of Pentaxim especially in China. In the Rest of the world, first-quarter sales of Polio/Pertussis/Hib vaccines decreased 43.6% to 25 million reflecting lower sales of the Polio vaccine, Imovax , and Hib vaccines in Japan.

In December 2014, Shantha was awarded an order for 37 million doses of Shan5TM, its pediatric pentavalent vaccine, to supply global health organizations in 2015 and 2016. The first 5.3 million doses of Shan5 , produced by Shantha, were delivered in March and sales in the first quarter were 7 million.

First-quarter sales of Menactra grew 50.0% to 87 million reflecting 62.2% growth in the U.S. due to favorable CDC order phasing.

Sales of Adult Booster vaccines were down 1.2% to 95 million in the first quarter.

First-quarter sales of Travel and Other Endemic vaccines declined 1.3% to 82 million.

Sales of Sanofi Pasteur MSD (not consolidated), the joint venture with Merck & Co. in Europe, were 139 million, (down 11.8% on a reported basis) in the first quarter due to lower sales of Gardasil .

Sales of Animal Health grew 13.5% to 658 million in the first-quarter confirming the recovery that started in 2014 and supported by both Companion and Production Animal segments. In the U.S. and in Emerging Markets, Animal Health sales grew 15.2% (to 307 million) and 8.9% (to 131 million), respectively.

First-quarter sales of the Companion Animals segment were up 13.1% to 443 million, reflecting the success of NexGard as well as performance of Heartgard . NexGard , Merial s next generation flea and tick product for dogs, was launched in the U.S. in the first quarter of 2014 and in Europe, Australia and Japan during 2014 and Brazil in the first quarter of 2015. Sales of NexGard more than doubled in the first quarter of 2015 compared to the same period of 2014. The Frontline family of products continued its stable performance over the period with sales up 1.2%

Sales of the Production Animals segment increased 14.5% to 215 million in the first-quarter. The Avian market, impacted last year by Avian influenza mostly in Asia, recovered in the first quarter while Merial increased its competitive response particularly in Emerging Markets. The Ruminant business was driven by the success of LongRange in the U.S. becoming a leading brand in parasite control.

Sales of Veterinary Public Health products were driven by an outbreak of Foot-and-Mouth disease in Korea where Merial is a key partner supporting the management of disease.

Net sales by geographic region

(a) World less the U.S., Canada, Western Europe, Japan, South Korea, Australia and New Zealand;

(b) France, Germany, UK, Italy, Spain, Greece, Cyprus, Malta, Belgium, Luxembourg, Portugal, Netherlands, Austria, Switzerland, Sweden, Ireland, Finland, Norway, Iceland, Denmark;

(c) Japan, South Korea, Canada, Australia and New Zealand;

In the U.S., sales were 2,976 million, up 1.0% in the first quarter. The strong performance of Genzyme (up 37.7%), Vaccines (up 15.4%), and Animal Health (up 15.2%) were partially offset by lower sales of Lantus (down 13.1%).

First-quarter sales in Emerging Markets increased 7.3% to 2,859 million. Pharmaceuticals sales in Emerging Markets increased 10.4% driven by Diabetes (up 18.5%), Genzyme (up 35.3%) and Generics (up 12.7%). Vaccines sales were down 19.4% ( 228 million) reflecting the delay of the Southern Hemisphere influenza campaign. Animal Health recorded good growth (up 8.9% to 131 million) driven by Avian products. Sales in China grew 7.7% to 484 million driven by vaccines, Lantus , Plavix , Aprovel and Depakine . First-quarter sales in Eastern Europe, Russia and Turkey were up 8.6% to 586 million led by good performance in Turkey, Hungary, Poland and Ukraine. Sales in Russia were 132 million, up 0.5%. In Africa and Middle-East, sales were 530 million, up 2.7%. In Latin America, sales reached 846 million, up 7.1% reflecting significantly higher sales in Venezuela that were partially offset by lower sales of vaccines (down 66.9%) in this region. Despite the strong performance of Genzyme (up 64.3%) and generics (up 9.6%), sales in Brazil decreased 20.9% to 283 million, impacted by lower sales of vaccines (down 85.3%). In Venezuela, significantly increased demand was observed in the first quarter of 2015, due to buying patterns associated with local market conditions. As a consequence, first-quarter sales in Venezuela were 200 million versus 66 million in the same period of 2014. Sanofi does not expect this increased demand to be replicated throughout 2015. This positive impact from Venezuela on Emerging Market sales was partially offset by low influenza vaccines sales ( 20 million in the first quarter of 2015 versus 105 million in the same period of 2014) due to the delay of the influenza campaign.

First-quarter sales in Western Europe were 2,031 million (up 0.6%). The performance of Genzyme (up 24.2%) and Animal Health (+8.5%) was partially offset by the impact of generic competition to Aprovel and Plavix .

In Japan, sales were 569 million, a decrease of 8.2% in the first-quarter, reflecting the impact of generic competition to Taxotere , Myslee and Amaryl , lower sales of vaccines and Plavix .

Consult Appendix 6 for full overview of Sanofi s R&D pipeline

Regulatory updates since the publication of the 2014 results on February 5, 2015 include the following:

In April, the FDA granted Fast Track designation to GZ/SAR402671, Genzyme s oral substrate reduction therapy, for the treatment of Fabry disease.

In March, Quadracel (Diphtheria, tetanus, pertussis, polio vaccine) was approved in the U.S. in children 4-6 years of age.

In March, Cerdelga (eliglustat), an oral treatment for certain adults living with Gaucher disease type 1, was approved in Japan and in February in Australia.