Sanofi Acquires Principia for $3.7 Billion, Gaining Control of Promising MS Drug

Sanofi has agreed to pay $3.7 billion for San Francisco-based Principia Biopharma, giving the French drugmaker full control of a potential multiple sclerosis drug.

Sanofi and Principia have been co-developing SAR442168, the first Bruton’s tyrosine kinase (BTK) inhibitor aimed at treating multiple sclerosis. Thus far, BTK inhibitors have only been used to treat cancer.

BTK is an enzyme present in the signaling pathways of key immune system cells. Inhibiting the enzyme can help arrest inflammation and tissue destruction related to autoimmune conditions.