Rilzabrutinib

Sanofi’s Wayrilz recommended for EU approval by the CHMP to treat immune thrombocytopenia Recommendation based on LUNA 3 phase 3 study demonstrating rapid and durable platelet response and significant improvements in bleeding, quality of life measures, and other ITP symptoms If approved, Wayrilz will be the first BTK inhibitor for ITP in the EU, targeting the root cause of the disease through multi-immune modulation Paris, October 17, 2025. The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has adopted a positive opinion recommending the approval of Wayrilz (rilzabrutinib) as a new treatment for immune thrombocytopenia (ITP) in adult patients who are refractory to other treatments. A final decision is expected in the coming months. “The CHMP’s recommendation of Wayrilz for approval is a positive step forward for people in the EU living with ITP who continue to experience symptoms that impact their daily living despite treatment with certain other therapies,” said Brian Foard, Executive Vice President, Head of Specialty Care at Sanofi. “Through multi-immune modulation, Wayrilz shows promise in addressing the root cause of ITP – complex immune system dysregulation, reinforcing Sanofi’s commitment to finding novel ways to address unmet patient needs in rare and immunological diseases.” The positive CHMP opinion is based on the pivotal LUNA 3 phase 3 study (clinical study identifier: NCT04562766), presented at the 66th American Society of Hematology Annual Meeting and Exposition in December 2024 and also published in Blood. Wayrilz met both the primary and secondary endpoints, making LUNA 3 the first phase 3 study to show a positive impact on sustained platelet counts, bleeding, and other ITP symptoms with an oral, reversible, Bruton’s tyrosine kinase (BTK) inhibitor. Wayrilz has already been approved in the US and the United Arab Emirates. In addition to the EU, Wayrilz is currently under regulatory review for ITP in China. It received fast track and orphan drug designations (ODD) in the US for ITP, with similar orphan designations in the EU and Japan. In other indications under investigation, the US Food and Drug Administration (FDA) granted Wayrilz ODD for three additional rare diseases, including warm autoimmune hemolytic anemia (wAIHA), IgG4-related disease (IgG4-RD), and sickle cell disease (SCD). Wayrilz also received FDA fast track designation and EU orphan designation in IgG4-RD. About the LUNA 3 studyLUNA 3 (clinical study identifier: NCT04562766) was a randomized, multicenter, phase 3 study evaluating the efficacy and safety of Wayrilz vs. placebo in adult and adolescent patients with persistent or chronic ITP. Patients received either oral Wayrilz 400 mg twice a day or placebo through a 12- to 24-week double-blind treatment period, followed by a 28-week open-label treatment period, and then a four-week safety follow-up or long-term extension period. The adolescent part of the study is ongoing. The primary endpoint for the EU is the proportion of adult participants able to achieve platelet counts at or above 50,000/μL for at least eight out of the last 12 weeks of the 24-week blinded treatment period in the absence of rescue therapy. Secondary endpoints included time to platelet response (platelet count ≥50 x 109/L or between 30 x 109/L and <50 x 109/L and at least doubled from baseline in absence of rescue therapy), number of weeks maintaining a specific platelet response (i.e., doubled or within range), rescue therapy use, physical fatigue score, and bleeding score as assessed by change from baseline in Idiopathic Thrombocytopenic Purpura Bleeding Scale (IBLS) assessment at Week 25. About WayrilzWayrilz (rilzabrutinib) is the first BTK inhibitor for ITP that helps address the root cause of disease through multi-immune modulation. This innovative therapy is approved in the US for adults with persistent or chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment. Additionally, Wayrilz is approved in the United Arab Emirates for adult patients with persistent or chronic ITP who have had an insufficient response or intolerance to a previous treatment. BTK, expressed in B cells, macrophages, and other innate immune cells, plays a critical role in multiple immune-mediated disease processes and inflammatory pathways. With the application of Sanofi’s TAILORED COVALENCY® technology, Wayrilz can selectively inhibit the BTK target. Wayrilz is being studied across a variety of rare diseases, including wAIHA, IgG4-RD, and SCD. These additional indications are currently under investigation and have not been approved by regulatory authorities. About ITPITP is a disease of complex immune dysregulation that causes low platelet counts (<100,000/μL), resulting in a variety of bleeding symptoms and thromboembolism risk. Beyond bruising and bleeding, which can include potentially life-threatening episodes like intracranial hemorrhage, people living with ITP may experience reduced quality of life, including physical fatigue and cognitive impairment. About Sanofi Sanofi is an R&D driven, AI-powered biopharma company committed to improving people’s lives and delivering compelling growth. We apply our deep understanding of the immune system to invent medicines and vaccines that treat and protect millions of people around the world, with an innovative pipeline that could benefit millions more. Our team is guided by one purpose: we chase the miracles of science to improve people’s lives; this inspires us to drive progress and deliver positive impact for our people and the communities we serve, by addressing the most urgent healthcare, environmental, and societal challenges of our time.Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY Media RelationsSandrine Guendoul | + 33 6 25 09 14 25 | sandrine.guendoul@sanofi.com Evan Berland | +1 215 432 0234 | evan.berland@sanofi.comLéo Le Bourhis | + 33 6 75 06 43 81 | leo.lebourhis@sanofi.comVictor Rouault | + 33 6 70 93 71 40 | victor.rouault@sanofi.comTimothy Gilbert | + 1 516 521 2929 | timothy.gilbert@sanofi.comLéa Ubaldi | +33 6 30 19 66 46 | lea.ubaldi@sanofi.com Investor RelationsThomas Kudsk Larsen | +44 7545 513 693 | thomas.larsen@sanofi.comAlizé Kaisserian | + 33 6 47 04 12 11 | alize.kaisserian@sanofi.com Felix Lauscher | +1 908 612 7239 | felix.lauscher@sanofi.comKeita 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.comThibaud Châtelet | +33 6 80 80 89 90 | thibaud.chatelet@sanofi.com Yun Li | +33 6 84 00 90 72 | yun.li3@sanofi.com Sanofi forward-looking statementsThis 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 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, 2024. 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. Attachment Press_Release

The European Medicines Agency’s human medicines committee (CHMP) rejected Sanofi’s Rezurock after a clinical trial was cut short because it showed no benefits in patients. Rezurock, which is available in the US for the treatment of chronic graft-versus-host disease after other therapies, failed to gain favor with European regulators over issues in the drug’s clinical trial data, according to the Friday press release . CHMP said it was difficult to quantify the effect of the therapy in patients who had tried other treatments, and that the main clinical trial supporting its review did not compare Rezurock to other drugs. CHMP noted further that Sanofi stopped a study early due to Rezurock’s “lack of evidence of a benefit” as a first-line treatment in patients. The committee said it considered a conditional marketing authorization for the drug if Sanofi would submit more data within a short period of time. Sanofi, however, is not planning to provide any further data before April 2030, CHMP said. Rezurock was being evaluated as a treatment for chronic GvHD after at least two lines of systemic therapy failed. Sanofi acquired the Rezurock through its merger with Kadmon Holdings in September 2021, a few months after the FDA greenlit the drug in July 2021. Meanwhile, Sanofi secured a positive opinion from CHMP for a different drug, its BTK inhibitor Wayrilz, as a treatment for immune thrombocytopenia in adult patients who are resistant to other forms of therapy. Wayrilz secured FDA approval in August this year. CHMP also recommended Insmed’s Brinsupri as an oral, once-daily tablet for non-cystic fibrosis bronchiectasis, which would be the first drug approved for this indication in Europe. Brinsupri won FDA approval in August this year, in 10 mg and 25 mg doses. The agency further recommended extending the labels for eight drugs already approved in Europe: