Redx Pharma has announced promising Phase 1 clinical trial results for RXC008, a potential first-in-class treatment for fibrostenotic Crohn's disease, at the 20th Congress of European Crohn's and Colitis Organisation Conference (ECCO) in Berlin.
The oral pan-ROCK inhibitor, specifically designed to target the gastrointestinal tract, demonstrated strong safety and efficacy signals in healthy participants, marking a significant step forward in addressing an unmet medical need.
Safety and Tolerability Profile
The Phase 1 study evaluated single doses up to 1000mg and daily doses up to 300mg over 14 days. Results showed RXC008 was well-tolerated across all dosing regimens, with no serious adverse events reported in the single ascending dose (SAD) study. The multiple ascending dose (MAD) study recorded only mild to moderate adverse events, with no treatment discontinuations required.
Notably, the drug showed no signs of hypotension or tachycardia – common concerns with systemic pan-ROCK inhibitors – confirming its gut-restricted design functionality.
Therapeutic Potential and Tissue Distribution
Crucial pharmacokinetic data demonstrated RXC008's successful targeting of the gastrointestinal tract. The drug achieved predicted efficacious concentrations in ileum and colon tissue samples, while maintaining minimal systemic exposure even at 300mg daily doses. This profile suggests a potentially favorable therapeutic window for treating intestinal fibrosis.
Clinical Significance
"RXC008 demonstrates the first-in-class potential for a novel treatment for fibrostenotic Crohn's disease," stated Dr. Florian Rieder, lead investigator from Cleveland Clinic. "Anti-inflammatories may suppress inflammation but do not treat the underlying fibrosis, leaving patients with invasive endoscopic or surgical interventions as their only therapeutic option."
The development addresses a significant medical need, as more than 50% of Crohn's disease patients develop significant fibrosis and stricture formation within ten years of diagnosis. Currently, no drugs are specifically approved for treating this fibrotic complication.
Study Design and Methodology
The Phase 1 trial comprised both SAD and MAD components. The SAD portion included 6 cohorts randomized 2:1 to receive single oral doses of RXC008 or placebo between 10 and 1000mg. The MAD study involved 3 cohorts randomized 3:1 to receive daily doses of 30, 100, or 300mg RXC008 or placebo for 14 days.
Comprehensive safety monitoring included 24-hour blood pressure tracking and telemetry to evaluate potential hypotensive effects. MAD participants underwent ileocolonoscopy on Day 14 to assess tissue drug concentrations.
Future Development
Dr. Helen Timmis, Interim Chief Medical Officer at Redx Pharma, expressed optimism about the results: "We have now demonstrated that oral administration of RXC008 is safe and well tolerated with exposure in the relevant GI-tissue and minimal systemic exposure."
The company is planning to initiate a Phase 2 study in the second half of 2025, potentially offering new hope for the approximately 1.7 million people globally affected by Crohn's disease.
