ReViral

ReViral was a clinical-stage biopharmaceutical company focused on developing and commercializing antiviral therapeutics for respiratory syncytial virus (RSV) infections. Founded in 2011 by Dr. Ken Powell, Dr. Stuart Cockerill, and Neil Mathews, the company aimed to address the significant unmet medical need for RSV treatments, particularly in high-risk populations like infants, the elderly, and the immunocompromised. Cockerill, who served as Chief Scientific Officer, previously led the team at GSK that discovered Tykerb™ for metastatic breast cancer, while Mathews was a project leader for a critical Hepatitis C project at Arrow Therapeutics prior to its acquisition.

The company's lead product candidate was sisunatovir, an orally administered small-molecule inhibitor designed to block the fusion of the RSV virus with a host cell. This mechanism prevents viral entry and replication. Sisunatovir was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) and was being evaluated in global Phase 2 clinical trials for both pediatric and adult patient populations. ReViral also had a second program in Phase 1 clinical development focused on inhibiting RSV replication by targeting the N-protein.

In April 2022, Pfizer entered into a definitive agreement to acquire ReViral, a deal that was completed in June 2022. The total consideration for the acquisition was up to $525 million, including upfront payments and development milestones. Pfizer anticipated that, if successful, the annual revenue from these programs could exceed $1.5 billion. The acquisition was seen as a strategic move for Pfizer to enhance its anti-infective pipeline and complement its own RSV vaccine program. However, as of early 2025, development of sisunatovir has been discontinued.

Keywords: respiratory syncytial virus, RSV, antiviral therapeutics, sisunatovir, Pfizer acquisition, fusion inhibitor, N-protein inhibitor, clinical-stage, biopharmaceutical, infectious diseases, virology, drug development, Ken Powell, Stuart Cockerill, Alex Sapir, small molecule inhibitor, antiviral drugs, pediatric RSV, adult RSV, viral replication