Redx Pharma's Zelasudil Shows Promise in Phase 2a IPF Trial with 47% Reduction in Lung Function Decline
核心洞察
Zelasudil, a selective ROCK2 (搜索) inhibitor, demonstrated a 47% reduction in forced vital capacity decline at 20mg twice daily in IPF (搜索) patients during a 12-week Phase 2a study.
The drug showed excellent tolerability with no treatment-related serious adverse events and successfully combined with standard-of-care antifibrotic agents pirfenidone and nintedanib.
Circulating biomarkers including CA19-9, CA-125, PRO-C3 and CHI3L1 supported the anti-fibrotic activity observed in the 48-patient randomized trial.
Redx Pharma (搜索) presented encouraging Phase 2a data for zelasudil (RXC007), a selective ROCK2 (搜索) inhibitor, showing the experimental drug reduced lung function decline in patients with idiopathic pulmonary fibrosis (搜索) (IPF (搜索)) at the European Respiratory Society meeting in Amsterdam. The signal-searching study demonstrated that zelasudil was well-tolerated and could be safely combined with existing standard-of-care treatments.
Study Design and Patient Population
The randomized, double-blind Phase 2a study enrolled 48 patients with IPF (搜索), with baseline demographics and disease characteristics balanced across treatment groups and consistent with historical IPF studies. Patients were randomized in a 3:1 ratio to receive zelasudil or placebo twice daily for 12 weeks at doses of 20mg BID and 50mg BID. In each cohort, patients were split between either no background therapy or stable doses of pirfenidone or nintedanib.
Following the 12-week double-blind treatment period, 35 of the 48 patients continued into a 12-week open-label extension, allowing placebo patients to cross over to zelasudil treatment.
Efficacy Results Show Lung Function Stabilization
Zelasudil demonstrated numerical reductions in forced vital capacity (FVC) decline compared to placebo at 12 weeks. Patients receiving 20mg BID showed a 47% reduction in FVC decline (58ml), while those on 50mg BID experienced a 13% reduction in FVC decline (16ml).
During the open-label extension, patients who remained on zelasudil continued to benefit from treatment for the entire 24-week treatment period. Notably, stabilization in lung function was also observed in placebo patients who switched to zelasudil.
Professor Toby Maher, zelasudil Phase 2 Chief Investigator and Professor of Clinical Medicine and Director of the Interstitial Lung Disease Programme at Keck School of Medicine at the University of Southern California, commented: "The data from this study shows zelasudil has the potential to improve lung function in IPF (搜索) patients with relevant circulating biomarker data that supports the anti-fibrotic activity of the compound."
Safety Profile and Biomarker Support
The study demonstrated that zelasudil was well tolerated at both doses with or without background antifibrotic therapy. There were no deaths or treatment-related serious adverse events observed. The most common treatment-related adverse event was asymptomatic ALT/AST increases, which resolved with treatment interruption. Importantly, there were no associated bilirubin increases or Hy's law cases, no evidence of hypotension, and no gastrointestinal-related signals.
Circulating biomarker data supported the anti-fibrotic signal observed, including changes in CA19-9, CA-125, PRO-C3, and CHI3L1. Pharmacokinetic data matched predictions from Phase 1 healthy volunteer studies, with both doses tested falling within the predicted efficacious range.
Combination Potential with Standard Care
The study successfully demonstrated zelasudil's combinability with standard-of-care agents, showing no clinically relevant drug-drug interactions with either nintedanib or pirfenidone. This finding is particularly significant given that most IPF (搜索) patients receive these established antifibrotic treatments.
Professor Maher noted: "It is also exciting to see that zelasudil can be easily combined with standard of care anti-fibrotic agents."
ROCK2 Mechanism and Clinical Rationale
Zelasudil is a potent, oral, small molecule, selective Rho Associated Coiled-Coil Containing Protein Kinase 2 (搜索) (ROCK2 (搜索)) inhibitor. ROCK is well established as an anti-fibrotic target consisting of two isoforms, ROCK1 and ROCK2. While pan-ROCK inhibition shows robust anti-fibrotic activity in preclinical models, systemic pan-ROCK inhibition results in hypotension. Selective ROCK2 inhibition avoids this side effect while maintaining anti-fibrotic efficacy across multiple preclinical fibrosis models including lung, liver, kidney, skin, chronic graft-versus-host disease, and cancer-associated fibrosis.
Addressing Unmet Medical Need
IPF (搜索) affects over 170,000 patients globally, with approximately 53,000 new diagnoses annually across the US, EU5, and Japan. The disease primarily affects older adults over 50 years and involves irreversible scarring, stiffening, and thickening of lung tissues, leading to shortness of breath and reduced oxygen absorption. Patients diagnosed with IPF have an estimated life expectancy of 3 to 5 years, and there is no known cure.
Dr. Helen Timmis, Chief Medical Officer at Redx Pharma (搜索), emphasized the clinical need: "IPF (搜索) is a devastating disease with no new treatments approved in the last decade. This signal searching study is very encouraging in demonstrating the tolerability, combinability and an efficacy signal at this early time point."
Next Steps and Partnership Strategy
The encouraging data support further investigation of zelasudil as a potential treatment for IPF (搜索) and other interstitial lung diseases. Redx is actively seeking a partner to support the next stages of clinical development, positioning zelasudil for potential advancement into larger, pivotal trials that could establish its role in IPF treatment.