Sanofi, a major pharmaceutical company with a significant presence in Massachusetts, announced plans to lay off 229 employees following its acquisition of the Cambridge-based biotech firm Blueprint Medicines. The job reductions, detailed in a filing with the Massachusetts Executive Office of Labor and Workforce Development, will take place between October 9, 2026, and June 30, 2027.

Blueprint Medicines was acquired by Sanofi in July 2025 in a transaction valued at $9.1 billion. The biotech company brought to Sanofi a portfolio that includes a marketed therapy for systemic mastocytosis, a rare condition, as well as a pipeline of experimental immunology treatments. The acquisition strategically expanded Sanofi’s offerings in these therapeutic areas.

A Sanofi spokesperson said the workforce reductions are part of “thoughtful organizational decisions” made to align the company’s structure with its long-term business goals and the demands of its commercial portfolio and drug pipeline. The company emphasized that these steps were taken carefully to position itself for future success while continuing to meet patient needs.

Although the spokesperson confirmed that many Blueprint Medicines employees have transitioned to Sanofi, the company did not disclose the exact number of retained staff. Sanofi also stated that those impacted by the layoffs have been informed and that the company will provide various forms of support during their transition.

Sanofi, headquartered in Paris, employed approximately 4,200 people in Massachusetts last year, according to local business records. The planned job cuts highlight ongoing adjustments following the integration of Blueprint Medicines into Sanofi’s broader operations.