Positive Phase 1b/2 Results from Ongoing REC-4881 TUPELO Trial Demonstrate Rapid and Durable Reductions in Polyp Burden in Familial Adenomatous Polyposis (FAP) at 25 Weeks
Positive Phase 1b/2 Results from Ongoing REC-4881 TUPELO Trial Demonstrate Rapid and Durable Reductions in Polyp Burden in Familial Adenomatous Polyposis (FAP) at 25 Weeks Leave a reply REC-4881 (4 mg QD) achieved rapid clinical activity, with 75% of evaluable patients showing reductions in total polyp burden and a 43% median reduction after 12 weeks of treatment (n=12) After 12 weeks off therapy (week 25 of the study), 82% of evaluable patients (9 of 11) maintained a durable reduction in total polyp burden, with a 53% median reduction observed from baseline Natural history analysis showed that 87% of untreated FAP patients – who resembled the inclusion criteria of TUPELO – had annualized polyp-burden increase, 10% remained stable, and 3% showed modest decrease—underscoring the disease’s progressive trajectory (n=55) 40% of patients (4 out of 10) achieved a ≥1-point improvement in Spigelman stage—a clinically meaningful measure of upper GI disease severity to assess surveillance and clinical management REC-4881 (4 mg QD) has a safety profile consistent with MEK1/2 inhibition, with the majority of treatment-related adverse events being Grade 1 or 2, Grade 3 events occurring in 15.8% of the safety-evaluable patients, and no Grade ≥4 TRAEs reported to date First clinical validation of the Recursion OS, demonstrating how unbiased phenotypic and mechanistic insights—such as MEK1/2 rescue of APC loss-of-function—can translate to novel, differentiated therapeutics for diseases like FAP with no approved therapy and high prevalence of >50,000 patients in US and EU5 Next steps: Engage the FDA in the 1H26 to define a potential registration pathway, and in parallel, expand the population from ≥55 to ≥18 years old, and further optimize dosing schedule SALT LAKE CITY, Dec. 08, 2025 (GLOBE NEWSWIRE) — Recursion (Nasdaq: RXRX), a clinical-stage TechBio company decoding biology to radically improve lives, today announced positive Phase 1b/2 data from