Pharma BD Deal Intelligence
Pfizer agreed to acquire ReViral, a clinical-stage RSV antiviral biotech, for total consideration up to $525M including upfront and development milestones. Lead asset sisunatovir is an oral RSV fusion inhibitor with FDA Fast Track designation. Closed June 9, 2022. Note: existing DB record has data-quality issue (date 2002-07-15); this is the correct 2022 announcement. POST-CLOSE OUTCOME (reviewed 2026-06-07): The acquisition's clinical thesis failed. Pfizer discontinued sisunatovir in October 2024 for business reasons after 'ongoing challenges' in development, including a drug-drug interaction with antacids; there were no safety concerns. The adult RSV study NCT06079320 is listed as TERMINATED on ClinicalTrials.gov ('Study discontinued due to business reasons...no changes to sponsor's assessment of the risk-benefit profile'). Pediatric/infant studies were also halted. The second ReViral program (PF-07923567 / RV-299) had already been dropped in August 2023. Pfizer's RSV antiviral pipeline is now empty; its RSV strategy centers on the Abrysvo vaccine. Sources: ClinicalTrials.gov NCT06079320; FierceBiotech (2024-11-04); Endpoints News (2024-11-04).