Recursion Pharmaceuticals (NASDAQ:RXRX) gained 7% on Monday after releasing encouraging Phase 2 results for REC-4881, its investigational therapy for familial adenomatous polyposis (FAP)—a hereditary condition that currently has no approved treatments.
According to the company, REC-4881 showed rapid and meaningful clinical activity. Three-quarters of evaluable patients experienced a decrease in total polyp burden, with a median reduction of 43% after 12 weeks of therapy. Importantly, the gains persisted well beyond the treatment window: 82% of participants sustained polyp reductions 12 weeks after stopping the drug, with a median 53% reduction from baseline.
These improvements stand in stark contrast to historical trends showing that about 87% of untreated FAP patients typically see their polyp burden worsen over time. The treatment also demonstrated benefit in disease severity, with 40% of patients achieving a clinically significant improvement in Spigelman stage, which measures upper gastrointestinal involvement.
Jessica Stout, Principal Investigator of the TUPELO study and Assistant Clinical Professor at the University of Utah School of Medicine, said, “The durable polyp burden reduction demonstrated by REC-4881—especially the sustained effect seen at Week 25, 12 weeks after completing therapy—is highly encouraging for the FAP community.”
REC-4881 is an allosteric MEK1/2 inhibitor discovered through Recursion’s AI-driven Recursion OS platform. The company reported that the safety data aligned with expectations for MEK1/2 inhibition: most side effects were mild or moderate (Grade 1 or 2), and no Grade 4 or higher events were observed.
Recursion plans to meet with the FDA in the first half of 2026 to discuss a potential registration pathway, while also looking to broaden eligibility criteria and refine dosing approaches for future studies.