Sanofi to Acquire Blueprint Medicines for $9.5 Billion in Major Immunology Move

On June 2 local time, Sanofi and Blueprint announced a $9.5 billion acquisition agreement. According to public information, this is the largest transaction in the global rare disease field so far in 2025, and the second-largest acquisition in the pharmaceutical industry this year, only behind Johnson & Johnson's $14.6 billion acquisition of Intra-Cellular Therapies, a biopharmaceutical company focused on treating central nervous system diseases, in January 2025.

According to the terms, Sanofi will acquire all outstanding shares of Blueprint for $129.00 per share in cash.The total market capitalization is approximately 9.1 billion US dollars.Blueprint shareholders will also receive a non-tradable contingent value right (CVR), which will entitle holders to two potential milestone payments of $2 and $4 per CVR, respectively, for achieving future development and regulatory milestones in the BLU-808 pipeline.The total equity value of the transaction (including potential CVR payments) is approximately $9.5 billion (approximately RMB 68.285 billion) on a fully diluted basis.

The announcement shows that this offer price represents a premium of approximately 27% over Blueprint's closing price on May 30, 2025, and a premium of about 34% over Blueprint's 30-day volume-weighted average price (VWAP) as of May 30, 2025. Including the CVR, the premium is approximately 33% over the closing price on May 30, 2025, and about 40% over the 30-day VWAP.

If the tender offer is successfully completed, a wholly-owned subsidiary of Sanofi will merge with Blueprint, and all outstanding Blueprint shares not purchased 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 as offered to Blueprint shareholders in the tender offer. Sanofi plans to fund the transaction with a combination of cash on hand and proceeds from new debt, with the acquisition expected to close in the third quarter of 2025.

Blueprint is a U.S.-based publicly traded biopharmaceutical company focused on researching systemic mastocytosis (SM, a rare immune disorder) and other KIT-driven diseases. This acquisition primarily includes the commercially available immunological disease drug Ayvakit/Ayvakyt (avapritinib) and several immunological pipeline assets in the mid-to-late stages of clinical development.

Ayvakit/Ayvakyt is one of the core assets in this acquisition and the only approved drug for the treatment of advanced and indolent systemic mastocytosis.This is a rare immune disorder characterized by the abnormal proliferation and activation of mast cells in organs such as bone marrow, skin, and gastrointestinal tract. The drug is a potent and selective inhibitor of mutated KIT and PDGFRA kinases, designed to bind to and inhibit these proteins, effectively treating SM.

Currently, Ayvakit/Ayvakyt has been approved in 16 countries, including China, for one or more indications. In China, it is sold by CStone Pharmaceuticals, with royalties paid based on a tiered percentage of sales. Ayvakit/Ayvakyt achieved net revenue of $479 million in 2024 and nearly $150 million in the first quarter of 2025, representing year-over-year growth of over 60% compared to the first quarter of 2024.According to a report by FiercePharma, analysts predict that the annual sales of Ayvakit/Ayvakyt could reach $2 billion by 2030.

This acquisition will also bring elenestinib (a next-generation drug for the treatment of SM) and BLU-808 (a highly selective and potent oral wild-type KIT inhibitor).

Elenestinib is a next-generation potent and highly selective KITD816V inhibitor, currently undergoing a Phase 2/3 study (Clinical Trial Identifier: NCT04910685). This ongoing randomized, double-blind, placebo-controlled study aims to evaluate its efficacy and safety in patients with indolent systemic mastocytosis (ISM) and smoldering SM.

BLU-808 is a potent and selective wild-type KIT inhibitor developed based on Blueprint's expertise in mast cell biology. Wild-type KIT plays a central role in mast cell activation and is associated with various inflammatory diseases. The development of BLU-808 is expected to provide new solutions for the treatment of multiple immunological disorders.

It is not difficult to see that, compared with the early-stage clinical pipelines Sanofi acquired in the past, this acquisition not only brought Sanofi the commercialized product Ayvakit/Ayvakyt but also multiple immunology products in the mid-to-late clinical stages. This enhances its existing portfolio of commercialized products and accelerates Sanofi's transformation into a global immunology leader.

In recent years, Sanofi has been continuously expanding its immunology portfolio.

Among them, Sanofi's most impressive immunology product is Dupilumab. Since its first approval in 2017 for atopic dermatitis, Dupilumab has been approved globally for seven indications, including asthma, prurigo nodularis, chronic spontaneous urticaria, and eosinophilic esophagitis. In 2023, Dupilumab's global sales reached approximately $11.6 billion, representing a 33% year-over-year increase. According to Sanofi’s 2024 financial report, Dupilumab successfully defended its title as the "top autoimmune drug" with $14.179 billion in sales. Besides the approved indications, the drug is currently in Phase III clinical trials for several other indications, including allergic rhinitis, unexplained chronic pruritus, and bullous pemphigoid.

However, Dupixent's core patent is expected to expire in 2031, yet it accounts for over 20% of Sanofi's revenue. To reduce reliance on Dupixent and create a "second growth curve," Sanofi is accelerating acquisitions. In the announcement of this acquisition of Blueprint, Sanofi's CEO Paul Hudson stated, "Sanofi still retains significant capacity for further acquisitions." This indicates that Sanofi will likely continue its aggressive acquisition spree.

In fact, this is indeed the case. In addition to the recent acquisition of Blueprint, an immunology company, Sanofi also reached an agreement with biopharmaceutical company DrenBio this year to obtain immune-related pipelines.

In March 2025, Sanofi reached an agreement with DrenBio to acquire the latter's myeloid cell bispecific antibody DR-0201 for a total transaction value of $1.9 billion. DR-0201 is the first bispecific antibody developed by DrenBio based on its targeted myeloid cell agonist and phagocytosis platform. By binding to phagocytic receptors on tissue-resident/transporting myeloid cells and CD20 on the surface of B cells, it induces deep B-cell depletion. The acquisition of DR-0201 will strengthen Sanofi’s position in deep B-cell depletion therapies, particularly for difficult-to-treat autoimmune diseases like lupus. Sanofi stated that the addition of DR-0201 will synergize with its autoimmune pipeline, accelerating the development of innovative therapies aimed at immune system resetting.

In fact, the logic behind Sanofi's "heavy investment" in the immunology field is quite straightforward: the market is enormous and growing rapidly. Taking autoimmune diseases as an example, there is a market worth hundreds of billions waiting to be tapped. According to Frost & Sullivan data projections, by 2030, the global market size for autoimmune disease drugs is expected to reach $176 billion, with a compound annual growth rate (CAGR) of 3.6% from 2022 to 2030. In particular, China's market size is projected to reach nearly $25 billion by 2030, representing a tenfold increase from 2020, making it a significant source of growth for the global autoimmune drug market.

In addition to Sanofi, multinational corporations (MNCs) such as AbbVie, Novartis, Roche, Bristol-Myers Squibb, AstraZeneca, and Johnson & Johnson are also prioritizing this field. Chinese pharmaceutical companies like Hengrui Medicine, Huadong Medicine, Connaught Biotech, Zhixiang Jintai, CSPC Pharmaceutical Group, Akeso Biopharma, 3SBio, Connect Biopharma, Magi Biotech, Simcere Pharmaceutical, and Quanxin Biotech are also racing in this track.

After Dupilumab, where will the next blockbuster immunotherapy come from? Let's wait and see.