Sanofi to Lay Off 229 Blueprint Medicines Workers in Massachusetts, 13 Months After the $9.1 Billion Acquisition

Cuts spread from October to late June

The Boston Globe, citing the state filing, reported that the positions will be cut between Oct. 9 and late June of next year, and Fierce Pharma put the same window as October 2026 to June 2027. Sanofi's statement to reporters described the moves as "thoughtful organizational decisions to align our structure with our long-term business priorities and the needs of our commercial portfolio and pipeline," and added: "Many Blueprint employees are joining Sanofi. Those affected by these decisions have already been informed and we will continue to provide multiple avenues of support through their transitions." The spokesperson gave the Globe no figure for how many Blueprint staff are being retained.

Sanofi is one of the largest life-sciences employers in the state. The Business Journal's account, carried by NBC Boston, noted the company's lease of roughly 900,000 square feet at 350 and 450 Water Street in Cambridge Crossing, and the Globe cited a Business Journal figure of nearly 4,200 Sanofi employees in Massachusetts last year. A class-action firm, Strauss Borrelli, has opened a WARN Act investigation into whether affected Blueprint employees received the 60 days' notice the federal statute requires.

What Sanofi bought in 2025

Sanofi's July 18, 2025, completion release lists the assets that came with Blueprint: Ayvakit/Ayvakyt (avapritinib), which the company calls the only approved medicine for advanced and indolent systemic mastocytosis in the US and EU; elenestinib, a KIT D816V inhibitor in the HARBOR Phase 2/3 study (NCT04910685) in indolent SM; and BLU-808, an oral wild-type KIT inhibitor. The same release said the transaction would be financed from cash and commercial paper and would not materially change Sanofi's 2025 guidance. Pharmaphorum, reading Sanofi's recent financial reports, put Ayvakit net sales at 367 million euros in the first half of 2026.

Most of the executives who built that portfolio had already left before the WARN filing, and Fierce Pharma and pharmaphorum traced the exits: former CEO Kate Haviland became board chair of GC Therapeutics around the turn of the year, chief scientific officer Percy Carter moved to Pfizer to run preclinical and translational sciences, chief commercial officer Philina Lee is now CEO of AdvanCell, and, by pharmaphorum's count from LinkedIn, all 13 members of the leadership team listed on Blueprint's site at the time of the deal have left. Fierce framed the layoffs as the first major workforce reduction under Belén Garijo, who became Sanofi's CEO on May 1, 2026.

The STAT report that first surfaced this story on the scanner sits behind a subscription wall and was not read for this article. The account above rests on the Globe, Fierce Pharma, pharmaphorum and Business Journal coverage of the same state filing, plus Sanofi's own 2025 release. The WARN notice itself was not retrieved, because the Massachusetts labor department's report page refused the automated request.

Why This Matters to the APO|APE Reader

Belén Garijo told analysts on July 30, in her first earnings call as Sanofi's CEO, that she had to "fully acknowledge the challenges" facing the company and "the need to act with a sense of urgency," and Fierce Pharma read the Blueprint cuts as a possible prelude to a larger overhaul, comparing it with the $2.5 billion cost program GSK's Luke Miels unveiled about six months into his tenure. For the mastocytosis and KIT-driven disease programs, the practical change is that Ayvakit, elenestinib and BLU-808 are now carried by Sanofi's immunology organization without the company that built them, and 229 departures against a 682-person starting headcount is a third of what Sanofi bought 13 months ago.