SNYNF Sanofi (PK)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of September 2024

Commission File Number: 001-31368

SANOFI

(Translation of registrant’s name into English)

46, avenue de la Grande Armée, 75017 Paris, FRANCE

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F ☒   Form 40-F ☐

In September 2024, Sanofi published the press releases attached hereto as Exhibits 99.1, 99.2 and 99.3 which are incorporated herein by reference.

Exhibit Index

2

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

3

Exhibit 99.1

Press Release

Dupixent is the first and only biologic to achieve significant improvements in disease remission and symptoms in bullous pemphigoid positive pivotal study

Paris and Tarrytown, NY, September 11, 2024. A Dupixent (dupilumab) pivotal study (ADEPT) in bullous pemphigoid (BP) met the primary and all key secondary endpoints evaluating its investigational use in adults with moderate-to-severe disease. In the study, five times more Dupixent patients achieved sustained disease remission compared to those on placebo. Sustained disease remission was defined as complete clinical remission with completion of oral corticosteroids (OCS) taper by week 16 without relapse and no rescue therapy use during the 36-week treatment period. Dupixent was previously granted Orphan Drug Designation by the U.S. Food and Drug Administration for BP, which applies to investigational medicines intended for the treatment of rare diseases that affect fewer than 200,000 people in the U.S. This study will support regulatory submissions around the world, starting with the U.S. later this year.

BP, a chronic and relapsing disease, is characterized by intense itch and blisters, reddening of the skin, and painful chronic lesions. The blisters and rash can form over much of the body and cause the skin to bleed and crust, resulting in patients being more prone to infection and affecting their daily functioning.

Dietmar Berger, M.D., Ph.D.

Chief Medical Officer, Global Head of Development at Sanofi

“The itchy blisters caused by bullous pemphigoid can be so intense they are debilitating, especially for elderly patients. There is a significant unmet medical need for new medicines for people suffering with this hard-to-treat disease in which the standard of care is oral and topical corticosteroids and immunosuppressants – treatments that have poor clinical outcomes and safety concerns, respectively, and should be used sparingly in an elderly population. These positive pivotal results for bullous pemphigoid add to an immense body of scientific evidence that underscores the important role IL4 and IL13 play in driving diseases characterized by itch. Combined with the consistent safety profile of the other dermatology indications, these results show the potential of Dupixent to transform the treatment paradigm for bullous pemphigoid.”

In the ADEPT study, 106 adults with moderate-to-severe BP were randomized to receive Dupixent 300 mg (n=53) every two weeks after an initial loading dose or placebo (n=53),

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along with standard-of-care OCS. During treatment, all patients underwent a protocol-defined OCS tapering regimen if control of disease activity was maintained.

For the primary endpoint, 20% of Dupixent patients experienced sustained disease remission at 36 weeks compared to 4% for placebo (p=0.0114). For the components comprising the primary endpoint – with patients having to achieve all components – efficacy among patients receiving Dupixent compared to placebo was as follows*:

*Components were not separately included in pre-specified statistical analyses and are therefore nominal

For selected secondary endpoints, results for Dupixent compared to placebo were statistically significant as follows:

In this older population, overall rates of adverse events (AEs) were 96% (n=51) for Dupixent and 96% (n=51) for placebo. AEs more commonly observed with Dupixent compared to placebo in more than 3 patients included peripheral edema (n=8 vs. n=5), arthralgia (n=5 vs. n=3), back pain (n=4 vs. n=2), blurred vision (n=4 vs. n=0), hypertension (n=4 vs. n=3), asthma (n=4 vs. n=1), conjunctivitis (n=4 vs. n=0), constipation (n=4 vs. n=1), upper respiratory tract infection (n=3 vs. n=1), limb injury (n=3 vs. n=2), and insomnia (n=3 vs. n=2). There were no AEs leading to death in the Dupixent group and 2 AEs leading to death in the placebo group.

George D. Yancopoulos, M.D., Ph.D.

Board co-Chair, President, and Chief Scientific Officer at Regeneron

“Bullous pemphigoid is a debilitating skin disease with a high mortality rate due to infection. Dupixent is the first medication to show significant and robust impacts in this patient population. These latest pivotal results reaffirm the underlying role type-2 inflammation plays in driving multiple skin diseases. We look forward to further advancing this research and sharing the positive results from the bullous pemphigoid pivotal trial with regulatory authorities.”

Additionally, a small separate phase 3 study (Study A) evaluating the investigational use of Dupixent in adults with uncontrolled and severe chronic pruritus of unknown origin (CPUO) did not achieve statistical significance in its primary itch responder endpoint (despite favorable numerical improvements), but showed nominally significant improvements in all

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other itch endpoints including: change from baseline; percent of patients achieving no/mild itch; and change in itch-related quality of life from baseline. Safety results were generally consistent with the known safety profile of Dupixent in its approved dermatological indications. The Dupixent phase 3 study program in CPUO consists of Study A and Study B. Study B is planned to initiate as a subsequent pivotal study.

Detailed efficacy and safety results for both BP and CPUO studies are planned for presentation at a forthcoming medical meeting.

The safety and efficacy of Dupixent in BP and CPUO are currently under clinical investigation and have not been evaluated by any regulatory authority.

About the Dupixent BP pivotal study

ADEPT is a randomized, phase 2/3, double-blind, placebo-controlled study evaluating the efficacy and safety of Dupixent in 106 adults with moderate-to-severe BP for a 52-week treatment period. After randomization, patients received Dupixent or placebo every two weeks, with OCS treatment. During treatment, OCS taper was initiated after patients experienced two weeks of sustained control of disease activity. OCS tapering could start between four to six weeks after randomization and was continued as long as disease control was maintained, with the intent of completion by 16 weeks. After OCS tapering, patients were only treated with Dupixent or placebo for at least 20 weeks, unless rescue treatment was required.

The primary endpoint evaluated the proportion of patients achieving sustained disease remission at 36 weeks. Sustained disease remission was defined as complete clinical remission with completion of OCS taper by 16 weeks without relapse and no rescue therapy use during the 36-week treatment period. Relapse was defined as appearance of ≥3 new lesions a month or ≥1 large lesion (>10cm in diameter) that did not heal within a week. Rescue therapy could include treatment with high-potency topical corticosteroids, OCS (including increase of OCS dose during the taper or re-initiation of OCS after completion of the OCS taper), systemic non-steroidal immunosuppressive medications, or immunomodulating biologics.

Select secondary endpoints evaluated at 36 weeks included:

About the Dupixent CPUO phase 3 program

The Dupixent phase 3 program in CPUO consists of Study A and Study B. Study A was a randomized, phase 3, double-blind, placebo-controlled study evaluating the efficacy and safety of Dupixent in adults with uncontrolled, severe CPUO. During the 4-week run-in period, patients received a standard-of-care regimen comprised of a non-sedative antihistamine and moisturizer to confirm they were refractory to available options. During

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the following 24-week treatment period, patients received Dupixent or placebo every two weeks added to the standard-of-care regimen.

The primary endpoint evaluated the proportion of patients with a clinically meaningful improvement in itch from baseline at 24 weeks, measured by a ≥4-point reduction in the worst-itch numerical rating scale (WI-NRS; scale: 0-10). The key secondary endpoint evaluated the proportion of patients with a ≥4-point reduction in WI-NRS at 12 weeks. Additional secondary endpoints included:

Study B is planned to initiate as a subsequent pivotal study.

About Dupixent

Dupixent (dupilumab) is a fully human monoclonal antibody that inhibits the signaling of the interleukin-4 (IL4) and interleukin-13 (IL13) pathways and is not an immunosuppressant. The Dupixent development program has shown significant clinical benefit and a decrease in type-2 inflammation in phase 3 studies, establishing that IL4 and IL13 are key and central drivers of the type-2 inflammation that plays a major role in multiple related and often co-morbid diseases.

Dupixent has received regulatory approvals in more than 60 countries in one or more indications including certain patients with atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyposis, eosinophilic esophagitis, prurigo nodularis, chronic spontaneous urticaria, and chronic obstructive pulmonary disease in different age populations. More than 1,000,000 patients are being treated with Dupixent globally.

Dupilumab development program

Dupilumab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement. To date, dupilumab has been studied across more than 60 clinical studies involving more than 10,000 patients with various chronic diseases driven in part by type-2 inflammation.

In addition to the currently approved indications, Sanofi and Regeneron are studying dupilumab in a broad range of diseases driven by type-2 inflammation or other allergic processes in phase 3 studies, including chronic pruritus of unknown origin and bullous pemphigoid. These potential uses of dupilumab are currently under clinical investigation, and the safety and efficacy in these conditions have not been fully evaluated by any regulatory authority.

About Regeneron

Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and

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led by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to numerous approved treatments and product candidates in development, most of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases.

Regeneron pushes the boundaries of scientific discovery and accelerates drug development using our proprietary technologies, such as VelociSuite^®, which produces optimized fully human antibodies and new classes of bispecific antibodies. We are shaping the next frontier of medicine with data-powered insights from the Regeneron Genetics Center^® and pioneering genetic medicine platforms, enabling us to identify innovative targets and complementary approaches to potentially treat or cure diseases.

For more information, please visit www.Regeneron.com or follow Regeneron on LinkedIn, Instagram, Facebook or X.

About Sanofi

We are an innovative global healthcare company, driven by one purpose: we chase the miracles of science to improve people’s lives. Our team, across the world, is dedicated to transforming the practice of medicine by working to turn the impossible into the possible. We provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the center of our ambitions.

Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY

Sanofi Media Relations

Sandrine Guendoul | + 33 6 25 09 14 25 | sandrine.guendoul@sanofi.com

Evan Berland | + 1 215 432 0234 | evan.berland@sanofi.com

Victor Rouault | + 33 6 70 93 71 40 | victor.rouault@sanofi.com

Timothy Gilbert | + 1 516 521 2929 | timothy.gilbert@sanofi.com

Sanofi Investor Relations

Thomas Kudsk Larsen |+ 44 7545 513 693 | thomas.larsen@sanofi.com

Alizé Kaisserian | + 33 6 47 04 12 11 | alize.kaisserian@sanofi.com

Arnaud Delépine | + 33 6 73 69 36 93 |arnaud.delepine@sanofi.com

Felix Lauscher | + 1 908 612 7239 | felix.lauscher@sanofi.com

Keita Browne | + 1 781 249 1766 | keita.browne@sanofi.com

Nathalie Pham | + 33 7 85 93 30 17 | nathalie.pham@sanofi.com

Tarik Elgoutni | + 1 617 710 3587 | tarik.elgoutni@sanofi.com

Thibaud Châtelet | + 33 6 80 80 89 90 | thibaud.chatelet@sanofi.com

Regeneron Media Relations

Ilana Yellen | +1 914-330-9618| ilana.yellen@regeneron.com

Regeneron Investor Relations

Vesna Tosic | + 914-847-5443 | vesna.tosic@regeneron.com

Sanofi Forward-Looking Statements

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions, and expectations 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’s management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of Sanofi, that could cause

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actual results and developments to differ 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 the EMA, regarding whether and when to approve any drug, device or biological application that may be filed for any such product candidates as well as their decisions regarding labelling and other matters that could affect the availability or commercial potential of such product candidates, the fact that product candidates if approved may not be commercially successful, the future approval and commercial success of therapeutic alternatives, Sanofi’s ability to benefit from external growth opportunities, to complete related transactions and/or obtain regulatory clearances, risks associated with intellectual property and any related pending or future litigation and the ultimate outcome of such litigation, trends in exchange rates and prevailing interest rates, volatile economic and market conditions, cost containment initiatives and subsequent changes thereto, and the impact that pandemics or other global crises may have on us, our customers, suppliers, vendors, and other business partners, and the financial condition of any one of them, as well as on our employees and on the global economy as a whole. The risks and uncertainties also include the uncertainties discussed 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 Form 20-F for the year ended December 31, 2023. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.

All trademarks mentioned in this press release are the property of the Sanofi group apart from VelociSuite and Regeneron Genetics Center.

Regeneron Forward-Looking Statements and Use of Digital Media

This press release includes forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”), and actual events or results may differ materially from these forward-looking statements. Words such as “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. These statements concern, and these risks and uncertainties include, among others, the nature, timing, and possible success and therapeutic applications of products marketed or otherwise commercialized by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Products”) and product candidates being developed by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Product Candidates”) and research and clinical programs now underway or planned, including without limitation Dupixent^® (dupilumab); the likelihood, timing, and scope of possible regulatory approval and commercial launch of Regeneron’s Product Candidates and new indications for Regeneron’s Products, such as Dupixent for the treatment of bullous pemphigoid and/or chronic pruritus of unknown origin as discussed in this press release as well as other potential indications; uncertainty of the utilization, market acceptance, and commercial success of Regeneron’s Products and Regeneron’s Product Candidates and the impact of studies (whether conducted by Regeneron or others and whether mandated or voluntary), including the studies discussed or referenced in this press release, on any of the foregoing or any potential regulatory approval of Regeneron’s Products (such as Dupixent) and Regeneron’s Product Candidates; the extent to which the results from the research and development programs conducted by Regeneron and/or its collaborators or licensees (including the studies discussed or referenced in this press release) may be replicated in other studies and/or lead to advancement of product candidates to clinical trials, therapeutic applications, or regulatory approval; the ability of Regeneron’s collaborators, licensees, suppliers, or other third parties (as applicable) to perform manufacturing, filling, finishing, packaging, labeling, distribution, and other steps related to Regeneron’s Products and Regeneron’s Product Candidates; the ability of Regeneron to manage supply chains for multiple products and product candidates; safety issues resulting from the administration of Regeneron’s Products (such as Dupixent) and Regeneron’s Product Candidates in patients, including serious complications or side effects in connection with the use of Regeneron’s Products and Regeneron’s Product Candidates in clinical trials; determinations by regulatory and administrative governmental authorities which may delay or restrict Regeneron’s ability to continue to develop or commercialize Regeneron’s Products and Regeneron’s Product Candidates; ongoing regulatory obligations and oversight impacting Regeneron’s Products, research and clinical programs, and business, including those relating to patient privacy; the availability and extent of reimbursement of Regeneron’s Products from third-party payers, including private payer healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid; coverage and reimbursement determinations by such payers and new policies and procedures adopted by such payers; competing drugs and product candidates that may be superior to, or more cost effective than, Regeneron’s Products and Regeneron’s Product Candidates; unanticipated expenses; the costs of developing, producing, and selling products; the ability of Regeneron to meet any of its financial projections or guidance and changes to the assumptions underlying those projections or guidance; the potential for any license, collaboration, or supply agreement, including Regeneron’s agreements with Sanofi and Bayer (or their respective affiliated companies, as applicable) to be cancelled or terminated; the impact of public health outbreaks, epidemics, or pandemics (such as the COVID-19 pandemic) on Regeneron’s business; and risks associated with intellectual property of other parties and pending or future litigation relating thereto (including without limitation the patent litigation and other related proceedings relating to EYLEA^® (aflibercept) Injection), other litigation and other proceedings and government investigations relating to the Company and/or its operations (including the pending civil proceedings initiated or joined by the U.S. Department of Justice and the U.S. Attorney’s Office for the District of Massachusetts), the ultimate outcome of any such proceedings and investigations, and the impact any of the foregoing may have on Regeneron’s business, prospects, operating results, and financial condition. A more complete description of these and other material risks can be found in Regeneron’s filings with the U.S. Securities and Exchange Commission, including its Form 10-K for the year ended December 31, 2023 and its Form 10-Q for the quarterly period ended June 30, 2024. Any forward-looking statements are made based on management’s current beliefs and judgment, and the reader is cautioned not to rely on any forward-looking statements made by Regeneron. Regeneron does not undertake any obligation to update (publicly or otherwise) any forward-looking statement, including without limitation any financial projection or guidance, whether as a result of new information, future events, or otherwise.

Regeneron uses its media and investor relations website and social media outlets to publish important information about the Company, including information that may be deemed material to investors. Financial and other information about Regeneron is routinely posted and is accessible on Regeneron’s media and investor relations website (https://investor.regeneron.com) and its LinkedIn page (https://www.linkedin.com/company/regeneron-pharmaceuticals).

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Exhibit 99.2

Press Release

Dupixent phase 3 study confirms significant improvements in itch and hives for patients with CSU

Paris and Tarrytown, NY, September 11, 2024. A Dupixent (dupilumab) confirmatory phase 3 study (LIBERTY-CUPID Study C) met the primary and key secondary endpoints for the investigational treatment of patients with uncontrolled, biologic-naïve CSU receiving background therapy with antihistamines. CSU is a chronic skin condition that causes sudden and debilitating hives and persistent itch, which can impact quality of life. This positive study confirms results from Study A, the first phase 3 study of Dupixent in this setting. Earlier this year, Japan was the first country in the world to approve and launch Dupixent for adult and adolescent CSU patients based on the results from Study A.

Dietmar Berger, M.D., Ph.D.

Chief Medical Officer, Global Head of Development at Sanofi

“The positive pivotal data from this study reinforce the potential of Dupixent to offer a new treatment option for the many people suffering from chronic spontaneous urticaria who do not respond to standard-of-care antihistamines. With clinically meaningful reductions in itch and hives for patients receiving Dupixent, we look forward to sharing these data with the FDA to bring Dupixent to patients with CSU in the US as soon as possible. With Dupixent now treating 1 million patients across seven approved indications, these new results underscore there are still many more patients that Dupixent can potentially benefit.”

Study C enrolled 151 children and adults randomized to receive Dupixent (n=74) or placebo (n=77) added to standard-of-care histamine-1 (H1) antihistamines. At 24 weeks, efficacy among patients receiving Dupixent compared to placebo was as follows:

Notably, 30% of Dupixent-treated patients reported no urticaria (complete response), compared to 18% of those on placebo (p=0.02).

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The safety results were generally consistent with the known safety profile of Dupixent in its approved dermatological indications. Overall rates of treatment emergent adverse events (AE) were 53% for Dupixent and 53% for placebo. AEs more commonly observed with Dupixent (≥5%) compared to placebo included injection site reactions (12% vs. 4%), accidental overdose (7% vs. 3%), and COVID-19 infection (8% vs. 5%).

Detailed results from this study will be provided to the US Food and Drug Administration in response to the additional data requested for inclusion in the supplemental biologics application for Dupixent in CSU. These data are also planned for presentation at a forthcoming medical meeting.

George D. Yancopoulos, M.D., Ph.D.

Board Co-Chair, President, and Chief Scientific Officer at Regeneron

“Patients with uncontrolled chronic spontaneous urticaria experience debilitating itch and hives that appear without warning and disrupt their lives. With a nearly 50% reduction in itch and urticaria activity scores compared to placebo, these positive phase 3 results reaffirm the potential of Dupixent to bring relief and its well-established safety profile to those living with this chronic inflammatory skin disease.”

Outside of Japan, the safety and efficacy of Dupixent for CSU has not been fully evaluated by any regulatory authority.

About CSU

CSU is a chronic inflammatory skin disease driven in part by type-2 inflammation, which causes sudden and debilitating hives and persistent itch. CSU is typically treated with H1 antihistamines, medicines that target H1 receptors on cells to control symptoms of urticaria. However, the disease remains uncontrolled despite antihistamine treatment in many patients, some of whom are left with limited alternative treatment options. These individuals continue to experience symptoms that can be debilitating and significantly impact their quality of life.

About the Dupixent phase 3 CSU program (LIBERTY-CUPID)

The LIBERTY-CUPID Phase 3 study program evaluating Dupixent in CSU consists of Study A, Study B, and Study C.

Study C was a randomized, double-blind, placebo-controlled clinical study that evaluated the efficacy and safety of Dupixent as an add-on to standard-of-care antihistamines compared to antihistamines alone in 151 patients aged six years and older with CSU who remained symptomatic despite antihistamine use and were not previously treated with omalizumab (i.e., biologic-naïve). The primary endpoint assessed the change from baseline in itch at 24 weeks (measured by the weekly itch severity score [ISS7], 0-21 scale). A key secondary endpoint was the change from baseline in itch and hives at 24 weeks (measured by the weekly urticaria activity score [UAS7], 0-42 scale).

Study A supported the approval of Dupixent in Japan for the treatment of CSU in people aged 12 years and older whose disease is not adequately controlled with existing therapy.

Results from Study A and Study B, which assessed Dupixent in patients aged 12 years and older who were uncontrolled on standard-of-care H1 antihistamines and refractory to omalizumab, were published in The Journal of Allergy and Clinical Immunology.

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About Dupixent

Dupixent (dupilumab) is a fully human monoclonal antibody that inhibits the signaling of the interleukin-4 (IL4) and interleukin-13 (IL13) pathways and is not an immunosuppressant. The Dupixent development program has shown significant clinical benefit and a decrease in type-2 inflammation in phase 3 studies, establishing that IL4 and IL13 are key and central drivers of the type-2 inflammation that plays a major role in multiple related and often co-morbid diseases.

Dupixent has received regulatory approvals in more than 60 countries in one or more indications including certain patients with atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyposis, eosinophilic esophagitis, prurigo nodularis, CSU, and chronic obstructive pulmonary disease in different age populations. More than 1,000,000 patients are being treated with Dupixent globally.

Dupilumab development program

Dupilumab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement. To date, dupilumab has been studied across more than 60 clinical studies involving more than 10,000 patients with various chronic diseases driven in part by type-2 inflammation.

In addition to the currently approved indications, Sanofi and Regeneron are studying dupilumab in a broad range of diseases driven by type-2 inflammation or other allergic processes in phase 3 studies, including chronic pruritus of unknown origin and bullous pemphigoid. These potential uses of dupilumab are currently under clinical investigation, and the safety and efficacy in these conditions have not been fully evaluated by any regulatory authority.

About Regeneron

Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and led by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to numerous approved treatments and product candidates in development, most of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases.

Regeneron pushes the boundaries of scientific discovery and accelerates drug development using our proprietary technologies, such as VelociSuite^®, which produces optimized fully human antibodies and new classes of bispecific antibodies. We are shaping the next frontier of medicine with data-powered insights from the Regeneron Genetics Center^® and pioneering genetic medicine platforms, enabling us to identify innovative targets and complementary approaches to potentially treat or cure diseases.

For more information, please visit www.Regeneron.com or follow Regeneron on LinkedIn, Instagram, Facebook or  X.

About Sanofi

We are an innovative global healthcare company, driven by one purpose: we chase the miracles of science to improve people’s lives. Our team, across the world, is dedicated to

3/5

transforming the practice of medicine by working to turn the impossible into the possible. We provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the center of our ambitions.

Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY

Sanofi Media Relations

Sandrine Guendoul | + 33 6 25 09 14 25 | sandrine.guendoul@sanofi.com

Evan Berland | + 1 215 432 0234 | evan.berland@sanofi.com

Victor Rouault | + 33 6 70 93 71 40 | victor.rouault@sanofi.com

Timothy Gilbert | + 1 516 521 2929 | timothy.gilbert@sanofi.com

Sanofi Investor Relations

Thomas Kudsk Larsen |+ 44 7545 513 693 | thomas.larsen@sanofi.com

Alizé Kaisserian | + 33 6 47 04 12 11 | alize.kaisserian@sanofi.com

Arnaud Delépine | + 33 6 73 69 36 93 |arnaud.delepine@sanofi.com

Felix Lauscher | + 1 908 612 7239 | felix.lauscher@sanofi.com

Keita Browne | + 1 781 249 1766 | keita.browne@sanofi.com

Nathalie Pham | + 33 7 85 93 30 17 | nathalie.pham@sanofi.com

Tarik Elgoutni | + 1 617 710 3587 | tarik.elgoutni@sanofi.com

Thibaud Châtelet | + 33 6 80 80 89 90 | thibaud.chatelet@sanofi.com

Regeneron Media Relations

Ilana Yellen | +1 914-330-9618| ilana.yellen@regeneron.com

Regeneron Investor Relations

Vesna Tosic | + 914-847-5443 | vesna.tosic@regeneron.com

Sanofi forward-looking statements

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates regarding the marketing and other potential of the product, or regarding potential future revenues from the product. Forward-looking statements are generally identified by the words “expects”, “anticipates”, “believes”, “intends”, “estimates”, “plans” and similar expressions. Although Sanofi’s management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of Sanofi, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include among other things, unexpected regulatory actions or delays, or government regulation generally, that could affect the availability or commercial potential of the product, the fact that product may not be commercially successful, the uncertainties inherent in research and development, including future clinical data and analysis of existing clinical data relating to the product, including post marketing, unexpected safety, quality or manufacturing issues, competition in general, risks associated with intellectual property and any related future litigation and the ultimate outcome of such litigation, and volatile economic and market conditions, and the impact that pandemics or other global crises may have on us, our customers, suppliers, vendors, and other business partners, and the financial condition of any one of them, as well as on our employees and on the global economy as a whole. The risks and uncertainties also include the uncertainties discussed 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 Form 20-F for the year ended December 31, 2023. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.

All trademarks mentioned in this press release are the property of the Sanofi group apart from VelociSuite and Regeneron Genetics Center.

Regeneron Forward-Looking Statements and Use of Digital Media

This press release includes forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”), and actual events or results may differ materially from these forward-looking statements. Words such as “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. These statements concern, and these risks and uncertainties include, among others, the nature, timing, and possible success and therapeutic applications of products marketed or otherwise commercialized by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Products”) and product candidates being developed by Regeneron and/or its collaborators or licensees (collectively, “Regeneron’s Product Candidates”) and research and clinical programs now underway or planned, including without limitation Dupixent^® (dupilumab); the likelihood, timing, and scope of possible regulatory approval and commercial launch of Regeneron’s Product Candidates and new indications for Regeneron’s Products, such as Dupixent for the treatment of chronic spontaneous urticaria (“CSU”) as discussed in this press

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release as well as other potential indications; uncertainty of the utilization, market acceptance, and commercial success of Regeneron’s Products and Regeneron’s Product Candidates and the impact of studies (whether conducted by Regeneron or others and whether mandated or voluntary), including the studies discussed or referenced in this press release, on any of the foregoing or any potential regulatory approval of Regeneron’s Products (such as Dupixent for the treatment of CSU) and Regeneron’s Product Candidates; whether the results from the confirmatory Phase 3 trial discussed in this press release will be sufficient for purposes of the request from the U.S. Food and Drug Administration for additional data to include in the supplemental biologics application for Dupixent in CSU; the ability of Regeneron’s collaborators, licensees, suppliers, or other third parties (as applicable) to perform manufacturing, filling, finishing, packaging, labeling, distribution, and other steps related to Regeneron’s Products and Regeneron’s Product Candidates; the ability of Regeneron to manage supply chains for multiple products and product candidates; safety issues resulting from the administration of Regeneron’s Products (such as Dupixent) and Regeneron’s Product Candidates in patients, including serious complications or side effects in connection with the use of Regeneron’s Products and Regeneron’s Product Candidates in clinical trials; determinations by regulatory and administrative governmental authorities which may delay or restrict Regeneron’s ability to continue to develop or commercialize Regeneron’s Products and Regeneron’s Product Candidates; ongoing regulatory obligations and oversight impacting Regeneron’s Products, research and clinical programs, and business, including those relating to patient privacy; the availability and extent of reimbursement of Regeneron’s Products from third-party payers, including private payer healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid; coverage and reimbursement determinations by such payers and new policies and procedures adopted by such payers; competing drugs and product candidates that may be superior to, or more cost effective than, Regeneron’s Products and Regeneron’s Product Candidates; the extent to which the results from the research and development programs conducted by Regeneron and/or its collaborators or licensees may be replicated in other studies and/or lead to advancement of product candidates to clinical trials, therapeutic applications, or regulatory approval; unanticipated expenses; the costs of developing, producing, and selling products; the ability of Regeneron to meet any of its financial projections or guidance and changes to the assumptions underlying those projections or guidance; the potential for any license, collaboration, or supply agreement, including Regeneron’s agreements with Sanofi and Bayer (or their respective affiliated companies, as applicable) to be cancelled or terminated; the impact of public health outbreaks, epidemics, or pandemics (such as the COVID-19 pandemic) on Regeneron’s business; and risks associated with intellectual property of other parties and pending or future litigation relating thereto (including without limitation the patent litigation and other related proceedings relating to EYLEA^® (aflibercept) Injection), other litigation and other proceedings and government investigations relating to the Company and/or its operations (including the pending civil proceedings initiated or joined by the U.S. Department of Justice and the U.S. Attorney’s Office for the District of Massachusetts), the ultimate outcome of any such proceedings and investigations, and the impact any of the foregoing may have on Regeneron’s business, prospects, operating results, and financial condition. A more complete description of these and other material risks can be found in Regeneron’s filings with the U.S. Securities and Exchange Commission, including its Form 10-K for the year ended December 31, 2023 and its Form 10-Q for the quarterly period ended June 30, 2024. Any forward-looking statements are made based on management’s current beliefs and judgment, and the reader is cautioned not to rely on any forward-looking statements made by Regeneron. Regeneron does not undertake any obligation to update (publicly or otherwise) any forward-looking statement, including without limitation any financial projection or guidance, whether as a result of new information, future events, or otherwise. Regeneron uses its media and investor relations website and social media outlets to publish important information about the Company, including information that may be deemed material to investors. Financial and other information about Regeneron is routinely posted and is accessible on Regeneron’s media and investor relations website (https://investor.regeneron.com) and its LinkedIn page (https://www.linkedin.com/company/regeneron-pharmaceuticals).

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Exhibit 99.3

Press Release

Sanofi, RadioMedix, and Orano Med announce licensing agreement on next-generation radioligand medicine for rare cancers

Paris, France, and Houston, Texas, September 12, 2024. As part of its effort to develop innovative treatments for people living with rare cancers, Sanofi has entered into an exclusive licensing agreement with RadioMedix, Inc., a US clinical-stage biotechnology company developing radiopharmaceuticals for PET imaging and targeted alpha therapy (TAT) against unmet medical needs in cancer, and Orano Med, a French clinical-stage biotechnology company, subsidiary of the Orano Group, developing lead-212 (²¹²Pb) radioligand therapies (RLTs) against cancer.

This collaboration between Sanofi, RadioMedix and Orano Med focuses specifically on the late-stage project, AlphaMedix^TM (²¹²Pb-DOTAMTATE), which currently is being evaluated for the treatment of adult patients with unresectable or metastatic, progressive somatostatin-receptor expressing neuroendocrine tumors (NETs), a rare cancer. AlphaMedix^TM is a TAT which consists of a somatostatin receptor-targeting peptide complex radiolabeled with lead-212 (²¹²Pb) that serves as an in vivo generator of alpha particles.

Dietmar Berger

Chief Medical Officer, Global Head of Development, Sanofi

“We are excited to develop a leading-edge project in the rapidly evolving field of radioligand therapies in rare cancers. Early results for 212Pb have demonstrated its differentiated biophysical and clinical profile, reinforcing its potential to be a transformative radioligand therapeutic for patients across multiple difficult-to-treat rare cancers. This agreement underscores our efforts to explore innovative collaborations that leverage novel technologies to address the needs of people living with cancer.”

AlphaMedix^TM has recently been granted Breakthrough Therapy Designation in gastroenteropancreatic neuroendocrine tumors (GEP-NETs) from the US Food and Drug Administration (FDA) for patients who are naïve to peptide-receptor radionuclide therapy. The FDA’s decision was based on findings from phase 1ⁱ and 2 clinical studies, which found that AlphaMedix^TM was well tolerated and provided substantial reduction in tumor burden, with a durable response rate (ORR according to RECIST 1.1) of 62.5%.ⁱ AlphaMedix^TM is currently completing phase 2 clinical development, and the data is being discussed with the FDA for potential regulatory filing and approval.

Ebrahim S. Delpassand

Chairman and CEO, RadioMedix

“The Breakthrough Therapy Designation of AlphaMedix is a testament of its success in validating targeted alpha therapies. We see this as a potential for the future of nuclear oncology in general, and today it is pioneering next-generation treatment for patients with neuroendocrine tumors. In our research, we have seen that significantly higher energy delivery over much shorter path lengths in the tissue of alpha emitters can overcome the limitations of currently available beta emitter radioligand therapies. We believe 212Pb is an ideal alpha emitter with highly desirable physical and supply

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characteristics in comparison to other alpha emitters. RadioMedix has been one of the pioneers in the field of radioligand therapy in the U.S and, through this licensing agreement with Sanofi, our goal is to bring this potentially life-saving therapy to as many patients as possible.”

Julien Dodet

President and CEO, Orano Med

“At Orano Med, we are at the forefront of innovation in radioligand therapy and are developing a global industrial platform for the manufacture and distribution of our 212Pb-conjugated drugs. This marks a pivotal moment to expedite the development of this new therapy and in our fight against cancer. Through this agreement, we aim to lead the charge in advancing radioligand therapies with the ambition to revolutionize cancer therapeutics.”

Under the licensing agreement, Sanofi will be responsible for the global commercialization of AlphaMedix^TM, while Orano Med will be responsible for the manufacturing of AlphaMedix^TM through its global industrial platform currently under development. Under the terms of the agreement, RadioMedix and Orano Med will receive an upfront payment of €100 million and up to €220 million in sales milestones and be eligible for tiered royalties. This agreement is subject to standard regulatory approvals required for transactions of this nature.

In striving to become the number one immunoscience company globally, Sanofi remains committed to advancing oncology innovation. Through focused strategic decisions the company has reshaped and prioritized its pipeline, leveraging its expertise in immunoscience to drive progress. Efforts are centered on difficult-to-treat cancers such as select hematologic malignancies, and solid tumors with critical unmet needs, including multiple myeloma, acute myeloid leukemia, certain types of lymphomas, as well as gastrointestinal and lung cancers.

About neuroendocrine tumors

Neuroendocrine tumors (NETs) are a heterogeneous group of rare cancers that originate from neuroendocrine cells. These cancers occur mostly in the gastrointestinal tract and pancreas but can also occur in other tissues including the thymus, lung, and other uncommon sites such as ovaries, heart, and prostate. Most NETs strongly express somatostatin receptors. In the United States, around 12,000 patients annually are expected to be diagnosed with neuroendocrine tumors, with an average 5-year survival rate of 60% at a metastatic stage. Despite the global prevalence of NETs increasing each year, it is considered a rare cancer that is estimated to affect approximately 35/100,000 individuals worldwide.

About RadioMedix

RadioMedix, Inc. is a clinical-stage biotechnology company, based in Houston and Humble, Texas. The company is focused on innovative targeted radiopharmaceuticals for diagnosis, monitoring, and therapy of cancer. RadioMedix is developing radiopharmaceuticals for PET imaging and therapy (alpha- and beta-labeled agents). The company established contract service facilities for academic and industrial partners. including a cGMP and analytical suite for Phase I-II-III clinical trials and commercial launch. To learn more, visit www.radiomedix.com and LinkedIn. For more information about this press release, please contact: radiomedix@knbcomm.com.

About Orano Med

Orano Med, a subsidiary of the Orano Group, is a clinical-stage biotechnology company that develops a new generation of targeted therapies against cancer using the unique properties of lead-212 (²¹²Pb), an alpha-emitting radioisotope and one of the more potent therapeutic payloads against cancer cells known as Targeted Alpha-Emitter Therapy (TAT). The company is developing several treatments using ²¹²Pb combined with various targeting agents. Orano Med has ²¹²Pb manufacturing facilities, laboratories, and R&D centers in France and in the US and is currently investing to further expand its GMP-manufacturing capacities for ²¹²Pb radiolabeled pharmaceuticals in North America and Europe.

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As a recognized international operator in the field of nuclear materials, Orano Group delivers solutions to address present and future global energy and health challenges. Its expertise and mastery of cutting-edge technologies enable Orano to offer its customers high value-added products and services throughout the entire fuel cycle. Every day, the Orano group’s 17,500 employees draw on their skills, unwavering dedication to safety and constant quest for innovation, with the commitment to develop know-how in the transformation and control of nuclear materials, for the climate and for a healthy and resource-efficient world, now and tomorrow.

About Sanofi

We are an innovative global healthcare company, driven by one purpose: we chase the miracles of science to improve people’s lives. Our team, across the world, is dedicated to transforming the practice of medicine by working to turn the impossible into the possible. We provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the center of our ambitions.

Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY

Contacts

Sanofi Media Relations

Sandrine Guendoul | + 33 6 25 09 14 25 | sandrine.guendoul@sanofi.com

Evan Berland | +1 215 432 0234 | evan.berland@sanofi.com

Nicolas Obrist | + 33 6 77 21 27 55 | nicolas.obrist@sanofi.com

Victor Rouault | + 33 6 70 93 71 40 | victor.rouault@sanofi.com

Timothy Gilbert | + 1 516 521 2929 | timothy.gilbert@sanofi.com

Sanofi Investor Relations

Thomas Kudsk Larsen |+ 44 7545 513 693 | thomas.larsen@sanofi.com

Alizé Kaisserian | + 33 6 47 04 12 11 | alize.kaisserian@sanofi.com

More contact information available here.

RadioMedix

radiomedix@knbcomm.com

Orano Med Media Relations

Sophie Letournel_| +33 6 38 44 34 11| sophie.letournel@orano.group

Orano Press Office | +33 (0)1 34 96 12 15| press@orano.group

Orano Med Investor relations

Marc Quesnoy | investors@orano.group

Sanofi Forward-Looking Statements

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions, and expectations 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’s management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of Sanofi, that could cause actual results and developments to differ 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 the EMA, regarding whether and when to approve any drug, device or biological application that may be filed for any such product candidates as well as their decisions regarding labelling and other matters that could affect the availability or commercial potential of such product candidates, the fact that product candidates if approved may not be commercially successful, the future approval and commercial success of therapeutic alternatives, Sanofi’s ability to benefit from external growth opportunities, to complete related transactions and/or obtain regulatory clearances, risks associated with intellectual property and any related pending or future litigation and the ultimate outcome of such litigation, trends in exchange rates and prevailing interest rates, volatile economic and market conditions, cost containment initiatives and subsequent changes thereto, and the impact that pandemics or other global crises may have on us, our customers, suppliers, vendors, and other business partners, and the financial condition of any one of them, as well as on our employees and on the global economy as a whole. The risks and uncertainties also include the uncertainties discussed 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 Form 20-F for the year ended December 31,

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2023. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.

All trademarks mentioned in this press release are the property of the Sanofi group with the exception of AlphaMedix.

ⁱ Delpassand ES, Tworowska I, Esfandiari R, et al. Targeted a-Emitter Therapy with 212Pb-DOTAMTATE for the Treatment of Metastatic SSTR-Expressing Neuroendocrine Tumors: First-in-Humans Dose-Escalation Clinical Trial. J Nucl Med. 2022;63(9):1326-1333. doi:10.2967/jnumed.121.263230.

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