- Recursion Pharmaceuticals' (RXRX, Financial) REC-4881 shows a median 43% reduction in polyp burden in FAP patients.
- Five out of six Phase 2 patients experienced polyp reductions between 31% and 82%.
- REC-4881 received Fast Track and Orphan Drug designations from the US FDA and European Commission.
Recursion Pharmaceuticals (RXRX) has announced promising preliminary results from its ongoing Phase 1b/2 TUPELO trial for REC-4881, an investigational MEK1/2 inhibitor targeting Familial Adenomatous Polyposis (FAP). The data, unveiled at Digestive Disease Week 2025, revealed a median 43% reduction in polyp burden at Week 13 among six efficacy-evaluable patients. Notably, 83% of these patients experienced polyp reductions ranging from 31% to 82%. However, one patient saw a substantial polyp increase of 595% from baseline.
FAP is a rare genetic disorder linked to mutations in the APC gene, leading to numerous gastrointestinal polyps and a nearly 100% lifetime risk of colorectal cancer if untreated. Approximately 50,000 people across the US and EU5 are affected by FAP, and currently, there are no FDA-approved treatments available.
REC-4881 demonstrated an acceptable safety profile, with most treatment-related adverse events being Grade 1-2. Grade 3 adverse events were observed in 16% of patients, and no Grade 4 events have been reported.
The US FDA and the European Commission have granted REC-4881 Fast Track and Orphan Drug designations, highlighting the drug's potential in addressing an unmet medical need. Recursion plans to continue with further efficacy and safety analyses anticipated in the second half of 2025 to further explore REC-4881's potential as a first-in-disease treatment option for FAP.
