On July 18, 2025 Sanofi reported the completion of its acquisition of Blueprint Medicines Corporation (Blueprint), adding to its portfolio a commercialized medicine, a promising pipeline, and the expertise of a company specializing in systemic mastocytosis (SM), a rare immunological disease, and other KIT-driven diseases (Press release, Sanofi, JUL 18, 2025, View Source [SID1234654438]).

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

In addition, the acquisition of Blueprint brings Sanofi an established presence among allergists, dermatologists, and immunologists which is expected to enhance Sanofi’s ability to advance its growing immunology pipeline.

The acquisition includes a rare immunology disease medicine, Ayvakit/Ayvakyt (avapritinib), approved in the US and EU. Ayvakit/Ayvakyt is the only approved medicine for advanced and indolent systemic mastocytosis (ASM & ISM), which is characterized by the accumulation and activation of aberrant mast cells in bone marrow, skin, the gastrointestinal tract, and other organs.

The acquisition also includes elenestinib, a next-generation medicine for SM that is a 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.

Sanofi also acquired BLU-808, an investigational oral, highly potent and selective wild-type KIT inhibitor. Wild-type KIT plays a central role in mast cell activation, which is implicated in a broad range of inflammatory diseases.

The tender offer for all outstanding shares of Blueprint common stock, par value $0.001 per share expired at 17:00 EDST, on Thursday, July 17, 2025. The minimum tender condition and all of the other conditions to the offer have been satisfied, and on July 17, 2025, Sanofi accepted for payment and will promptly pay for all shares validly tendered and not validly withdrawn.

Following its acceptance of the tendered shares, Sanofi completed its acquisition of Blueprint through the merger of a wholly owned subsidiary of Sanofi with and into Blueprint, pursuant to Section 251(h) of the General Corporation Law of the State of Delaware, with Blueprint continuing as the surviving corporation, and becoming an indirect, wholly owned subsidiary of Sanofi. Sanofi is financing the transaction with a combination of cash on hand and proceeds from commercial paper issuances and 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.

In connection with the merger, all Blueprint shares not validly tendered in the tender offer have been converted into the right to receive $129.00 per share in cash, without interest and subject to any withholding of taxes required by applicable legal requirements, plus one non-transferable contractual contingent right per share, representing the right to receive contingent payments of up to an aggregate amount of $6.00 per share in cash, without interest, upon the achievement of specified milestones on or prior to the expiration of the applicable milestone period.

As of July 18, 2025, Blueprint common stock will cease to be traded on the NASDAQ Global Select Stock Market.

About Ayvakit

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.