Pfizer to Buy ReViral, For Up To $525M


Pfizer Inc. (NYSE: PFE) is to acquire ReViral Ltd., a Stevenage, UK-based biopharmaceutical company focused on discovering, developing, and commercializing novel antiviral therapeutics that target respiratory syncytial virus (RSV).

The total consideration of the deal is up to $525 million, including upfront and development milestones. The proposed transaction is subject to customary closing conditions, including receipt of regulatory approvals.

The acquisition strengthens Pfizer’s capabilities in infectious disease research and development with a complementary strategy to help improve patient outcomes through treatment for respiratory syncytial virus (RSV) infections and prevent illness through vaccination.

Led by Alex C. Sapir, CEO, ReViral has a portfolio of therapeutic candidates, including sisunatovir, an orally administered inhibitor designed to block fusion of the RSV virus to the host cell. RSV is a respiratory pathogen, which can lead to severe and life-threatening lower respiratory tract infections (LRTIs) in high-risk populations, including young infants, immunocompromised individuals, and older adults. It is estimated to cause infections in approximately 64 million people, resulting in about 160,000 deaths, globally each year.

Sisunatovir significantly reduced viral load in a phase 2 RSV human challenge study in healthy adults and is currently in phase 2 clinical development in infants. The development program for sisunatovir is expected to continue in both adult and pediatric populations. A second program is focused on the inhibition of RSV replication targeting the viral N protein. The lead candidate in this program is currently in phase 1 clinical development.

Sisunatovir has been granted Fast Track designation by the U.S. Food and Drug Administration (FDA). In June 2021, ReViral announced the successful completion of Part A of the phase 2 REVIRAL1 study of sisunatovir for the treatment of RSV infections in hospitalized infants.

Backers in the company included CR-CP Life Science Fund, Andera Partners, Brace Pharma Capital, Green Sands Equity, New Leaf Venture Partners, Novo Holdings, OrbiMed Advisors, and Perceptive Advisors.