Palisade Bio’s ASCENTRA-UC PDE4 drug advances to Phase 2 with ulcerative colitis focus

Palisade Bio (PALI) highlighted its once-daily oral prodrug PDE4 inhibitor, PALI-2108, as it advances into a randomized, double-blind Phase 2b study for ulcerative colitis (UC) at the Stifel 2026 Virtual Immunology and Inflammation Forum. The drug, designed to avoid systemic exposure by local bioactivation in the distal ileum and colon, builds on Phase I data showing efficacy and tolerability improvements over traditional PDE4 inhibitors. Phase I results indicated that 40% of ulcerative colitis patients achieved clinical remission after 7 days of treatment, with 40% also showing endoscopic improvement, while Crohn’s disease patients saw a 47.5% reduction in disease activity scores after 14 days. The company’s strategy to mitigate gastrointestinal tolerability issues—such as diarrhea and nausea—by controlling drug release and concentration aligns with broader efforts in the biopharmaceutical sector to refine PDE4 inhibitor profiles for inflammatory bowel diseases (IBD). ASCENTRA-UC, the Phase 2b trial, plans to enroll approximately 204 patients across North America and Europe, with a primary endpoint of clinical remission at week 12. The study is powered to detect a 20 percentage-point improvement over placebo, assuming a 12.5% baseline remission rate. Regulatory milestones include U.S. Investigational New Drug (IND) clearance for ASCENTRA-UC in June 2024 and Canadian Clinical Trial Authorization (CTA) in September 2024. ASCENTRA-CD, a separate Phase 2 proof-of-concept study for Crohn’s disease, is expected to disclose 12-week endoscopic response data in the first quarter of 2028, with interim results potentially shared in 2027. Palisade Bio’s financial position, as of June 30, 2024, reflects $125 million in cash and no long-term debt, supporting its development pipeline. The company’s stock has seen a 167% return over the past year but has declined 28% year-to-date, with a beta of 1.55 and a trailing twelve-month current ratio of 24.26. Analysts rate PALI a strong buy, with price targets ranging from $5 to $25. The next earnings report is scheduled for November 16, 2026. Palisade Bio’s approach to differentiating its product profile—through clinical remission rates, endoscopic improvements, dose-response curves, tolerability, and long-term durability—positions ASCENTRA-UC as a potential competitor to existing therapies like apremilast, which has demonstrated clinical remission rates above 31% in ulcerative colitis studies, and afamelanotide, a topical PDE4 inhibitor developed by Hengrui Pharma, showing 57% remission rates in high-dose trials versus 13% placebo.