Sanofi to lay off 229 Blueprint employees, close offices

Sanofi is laying off 229 former Blueprint Medicines employees in Cambridge, MA and closing two legacy Blueprint facilities. The news comes just over a year after Sanofi's $9 billion acquisition of Blueprint, one of the biggest deals of 2025. 

Boston Business Journal broke the news, which pharmaphorum has independently verified with the company.

"As part of the integration following our acquisition of Blueprint Medicines in July 2025, we made thoughtful organisational decisions to align our structure with our long-term business priorities and the needs of our commercial portfolio and pipeline," Sanofi said in an emailed statement. "These decisions were made carefully to position the organisation for future success while continuing to deliver for patients. 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."

Blueprint's facilities at 45 Sidney St and 38 Sidney St in Cambridge are closing, with remaining Blueprint employees reporting to Sanofi's East Cambridge office.

Since the acquisition was finalised in July 2025, there's already been an exodus of Blueprint talent at the top levels of the company. All 13 members of Blueprint's leadership team (as listed on their website at the time) have left the company in the last year, with most departing in October of last year, according to LinkedIn.

Chief scientific officer Percy Carter has been leading preclinical and translational sciences at Pfizer, chief commercial officer Philina Lee is now CEO at AdvanceCell, R&D president Fouad Namouni is CEO at Synolo Therapeutics, and three separate members of the team - chief medical officer Dr Becker Hewes, chief business officer Sherwin Sattarzadeh, and SVP corporate affairs Jim Baker - have landed in similar roles at Damora Therapeutics, a Boston biotech focused on blood disorders.

Sanofi acquired Blueprint to secure the rights to Ayvakit/Ayvakyt (avapritinib), a tyrosine kinase inhibitor (TKI) that targets the KIT D816V mutation in ASM, an umbrella term that covers multiple disorders, including aggressive systemic mastocytosis, systemic mastocytosis with an associated haematological neoplasm (SM-AHN), and mast cell leukaemia (MCL).

Ayvakit is the only approved medicine for ASM, which causes symptoms like itching, fever, abdominal pain, and nausea, and can also lead to organ damage, bone fractures, and anaemia. People with ASM typically have a life expectancy ranging from six months to around three-and-a-half years.

According to recent Sanofi financial reports, Aykavit earned the company €367 million in net sales in the first half of 2026.