Investing.com-- French pharmaceutical giant Sanofi SA (EPA: SASY ) said on Wednesday it had entered an agreement to buy U.S.-listed biotech firm Vigil Neuroscience Inc (NASDAQ: VIGL ), with focus chiefly on an early-stage Alzheimer’s drug being developed by the firm.

Sanofi will pay $8 in cash for each share in Vigil, representing a 246% premium to the latter’s close on Wednesday. Sanofi said the deal is at an enterprise value of $470 million- a massive premium to Vigil’s current market capitalization of around $115 million.

Additionally, Sanofi will also pay Vigil shareholders $2 per share in cash on the first commercial sale of its Alzheimer’s drug- VG-3927.

VG-3927 is an early-stage drug that is set to be evaluated in a phase 2 clinical study in Alzheimer’s disease. The drug is intended to improve the neuroprotective function of microglia- specialized immune cells in the nervous system- to help against Alzheimer’s.

Sanofi had invested $40 million in Vigil in 2024 that granted it exclusive rights to VG-3927. The drug is targeted at helping the brain stop and reverse damage from the neurodegenerative disease.

Alzheimer’s is the most common form of dementia, with data from Alzheimer’s Association stating that at least 7.2 million Americans aged 65 and older are living with the disease in 2025.

Currently, about five Alzheimer’s therapies have been approved by the U.S. Food and Drug Administration- Rivastigmine by Novartis (SIX: NOVN ), Galantamine developed by a unit of Johnson & Johnson (NYSE: JNJ ), Donepezil by Pfizer (NYSE: PFE ), AbbVie Inc ’s (NYSE: ABBV ) Memantine, and Eli Lilly and Company’s (NYSE: LLY ) Kisluna.