Full Press Release Details
Sanofi to acquire Blueprint Medicines, expanding portfolio in rare immunological disease and adding early-stage pipeline
Paris and Cambridge, MA. June 2, 2025. Sanofi and Blueprint Medicines Corporation (Blueprint), a US-based, publicly traded biopharmaceutical company specializing in systemic mastocytosis (SM), a rare immunological disease, and other KIT-driven diseases, have entered into
an agreement under which Sanofi will acquire Blueprint.
The acquisition includes a rare immunology disease medicine, Ayvakit/Ayvakyt (avapritinib),
approved in the US and the EU, and a promising advanced and early-stage immunology pipeline. Furthermore, Blueprint s established presence among allergists, dermatologists, and immunologists is expected to enhance Sanofi s growing
immunology pipeline.
Ayvakit/Ayvakyt is the only approved medicine for advanced and indolent systemic mastocytosis (ASM & ISM), a rare
immunology disease, which is characterized by the accumulation and activation of aberrant mast cells in bone marrow, skin, the gastrointestinal tract, and other organs. The acquisition will also bring elenestinib, a next-generation medicine for SM,
as well as BLU-808, a highly selective and potent oral wild-type KIT inhibitor that has the potential to treat a broad range of diseases in immunology.
Under the terms of the acquisition, Sanofi will pay $129.00 per share in cash at closing, representing an equity value of approximately $9.1 billion.
Blueprint shareholders also will receive one non-tradeable contingent value right (CVR) which will entitle the holder to receive two potential milestone payments of $2 and $4 per CVR for the achievement,
respectively, of future development and regulatory milestones for BLU-808. The total equity value of the transaction, including potential CVR payments, represents approximately $9.5 billion on a fully
proposed acquisition of Blueprint Medicines represents a strategic step forward in our rare and immunology portfolios. It enhances our pipeline and accelerates our transformation into the world s leading immunology company. This acquisition is
fully aligned with our strategic intent to strengthen our existing therapeutic areas, to bring relevant and differentiated medicines to patients and to secure attractive returns to our shareholders. It complements recent acquisitions of early-stage
medicines that remain our main field of interest. Sanofi still retains a sizeable capacity for further acquisitions. We are excited to welcome Blueprint s talented people and we look forward to chasing the miracles of science together. This
makes sense for science, for both companies, for healthcare professionals, and most of all for patients.
CEO, Blueprint Medicines
Since our founding, Blueprint Medicines has worked at the intersection of scientific innovation and operational excellence. I m
incredibly proud of the medical innovations our people have created and delivered to patients. We have translated our unique scientific understanding of mast cell biology into a portfolio of important therapies including Ayvakit the first and
only medicine approved to treat the root cause of systemic mastocytosis and worked collaboratively with communities to improve standards of care and patient outcomes. With this agreement, we begin our next chapter with Sanofi, whose
exceptional leadership in rare disease and immunology and proven ability to solve medical challenges at scale stand to accelerate our joint mission to bring life-changing medicines to many more patients around the world.
Mast cells play an important role in immune responses and are typically found in tissues that encounter the
external environment, such as the skin, lungs, and gastrointestinal tract. Upon activation, mast cells release pro-inflammatory molecules such as histamines and proteases. Systemic mastocytosis is a rare
immunologic disorder that can lead to a range of debilitating symptoms across multiple organ systems and a significant impact on patients quality of life. The symptoms that patients with SM experience can include anaphylaxis, bone disease,
gastrointestinal distress and skin lesions. ISM represents the majority of SM cases.
Ayvakit achieved net revenues of $479 million in 2024 and
nearly $150 million in Q1 2025, representing year-on-year growth of more than 60 percent over Q1 2024. The oral medicine is a potent and selective inhibitor of
activated KIT and PDGFRA mutant kinases. In certain diseases, mutations in KIT and PDGFRA force protein kinases into an increasingly active state and Ayvakit/Ayvakyt is designed to bind and inhibit these proteins.
Elenestinib is a next-generation, potent and highly selective KIT D816V inhibitor with limited central nervous system penetration. The oral investigational
ISM medication is the subject of HARBOR, a phase 2/3 study (clinical study identifier: NCT04910685). The ongoing, randomized, double-blind, placebo-controlled study is designed to evaluate the efficacy and safety of elenestinib plus symptom-directed
therapy in patients with ISM and smoldering SM.
BLU-808 is an investigational oral, highly potent and selective
wild-type KIT inhibitor that was developed leveraging Blueprint s expertise in mast cell biology. Wild-type KIT plays a central role in mast cell activation, which is implicated in a broad range of inflammatory diseases.
Transaction terms and financial considerations
Under the terms of the merger agreement, Sanofi will commence a cash tender offer to acquire all outstanding shares of Blueprint for $129.00 per share in cash,
reflecting a total equity value of approximately $9.1 billion. In addition, Blueprint s shareholders will receive one non-tradeable CVR per Blueprint share with two potential milestone payments as
The upfront offer price represents a premium of approximately 27% over the closing
price of Blueprint on May 30, 2025 and a premium of approximately 34% over the 30 trading days volume weighted average price (VWAP) of Blueprint as of May 30, 2025. Together with the CVR, the premium is approximately 33% over the closing
price on May 30, 2025 and approximately 40% over the 30 trading days VWAP.
The consummation of the tender offer is subject to customary closing
conditions, including the tender of a number of shares of Blueprint common stock representing at least a majority of the outstanding shares of Blueprint common stock, the receipt of required regulatory approvals, and other customary conditions.
If the tender offer is successfully completed, a wholly owned subsidiary of Sanofi will merge with and into Blueprint and all of the outstanding Blueprint
shares that are not tendered in the tender offer will be converted into the right to receive the same $129.00 per share in cash and one CVR per share offered to Blueprint shareholders in the tender offer. Sanofi plans to finance the transaction with
a combination of cash on hand and proceeds from new debt. The tender offer is not subject to any financing condition. Subject to the satisfaction or waiver of customary closing conditions, Sanofi currently expects to complete the acquisition in
the third quarter of 2025. The acquisition will not have a significant impact on Sanofi s financial guidance for 2025. It is immediately accretive to gross margin and accretive to business operating income and EPS after 2026.
Conference call for investors and analysts
Sanofi will host a conference call for investors and analysts at 08:30 CEST today. A presentation will be available for download from the Investor Relations
section of sanofi.com before the conference call starts.
The call will be held on Zoom with the following access details:
Webinar ID: 979 9146 5119
Ayvakit (avapritinib) is the first and
only medicine approved by the US Food and Drug Administration (FDA) to treat the root cause of SM. It was FDA approved for the treatment of advanced SM in June 2021 and indolent SM in May 2023. It now is indicated in adults with ISM, adults with
advanced SM, including aggressive SM (ASM), SM with an associated hematological neoplasm (SM-AHN) and mast cell leukemia (MCL), and adults with unresectable or metastatic gastrointestinal stromal tumor (GIST)
harboring a PDGFRA exon 18 mutation, including PDGFRA D842V mutations. The medicine is approved in the EU as Ayvakyt for the treatment of adults with ISM with moderate to severe symptoms inadequately controlled on symptomatic treatment,
adults with ASM, SM-AHN or MCL, after at least one systemic therapy, and adults with unresectable or metastatic GIST harboring the PDGFRA D842V mutation. Globally, the medicine is approved for one or more
indications in 16 countries, including China where it is marketed by CStone Pharmaceuticals, paying tiered percentage royalties on sales.
Sanofi is an R&D driven, AI-powered biopharma company committed to improving people s lives and
creating 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
About Blueprint Medicines
Blueprint Medicines is a global, fully integrated biopharmaceutical company that invents life-changing medicines. We seek to alleviate human suffering
by solving important medical problems in two core focus areas: allergy/inflammation and oncology/hematology. Our approach begins by targeting the root causes of disease, using deep scientific knowledge in our core focus areas and drug discovery
expertise across multiple therapeutic modalities. We have a track record of success with two approved medicines, including Ayvakit/Ayvakyt (avapritinib) which we are bringing to patients with SM in the US and Europe. Leveraging our established
research, development, and commercial capability and infrastructure, we aim to significantly scale our impact by advancing a broad pipeline of programs ranging from early science to advanced clinical trials in mast cell diseases and solid tumors.
Blueprint Medicines is listed on NASDAQ: BPMC.
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
L o Le Bourhis | +33 6 75 06 43 81 | leo.lebourhis@sanofi.com
Victor Rouault | +33 6 70 93 71 40 | victor.rouault@sanofi.com
Timothy Gilbert | +1 516 521 2929 | timothy.gilbert@sanofi.com
L a Ubaldi | +33 6 30 19 66 46 | lea.ubaldi@sanofi.com
Sanofi Investor Relations
Thomas Kudsk Larsen |+
44 7545 513 693 | thomas.larsen@sanofi.com
Aliz Kaisserian | + 33 6 47 04 12 11 |
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 Ch telet | +33 6 80 80 89 90 | thibaud.chatelet@sanofi.com
Yun Li | +33 6 84 00 90 72 | yun.li3@sanofi.com
Blueprint Medicines Media Relations & Investor Relations
Jim Baker | +1 617 844 8236 | media@blueprintmedicines.com
Jenna Cohen | +1 857 209 3147 | ir@blueprintmedicines.com
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other things, unexpected regulatory actions or delays, or government regulation generally, that could affect the availability or commercial potential of the product, or the fact that the product may not be commercially successful, and risks related
to Sanofi s and Blueprint s ability to complete the acquisition on the proposed terms or on the proposed timeline or at all, including the receipt of required regulatory approvals, the risk that the conditions to the closing of the
transaction may not be satisfied, the possibility that competing offers will be made, the risks that the milestones related to the contingent value right will not be achieved, the risk of securityholder litigation relating to the proposed
acquisition, including resulting expense or delays, other risks associated with executing business combination transactions, such as the risk that the businesses will not be integrated successfully, that such integration may be more difficult,
time-consuming or costly than expected or that the expected benefits of the acquisition will not be realized, risks related to future opportunities and plans for the combined company, including uncertainty of the expected financial performance and