Dual α_vβ₆ and α_vβ₁ Inhibition over 12 Weeks Reduces Active Type I Collagen Deposition in Individuals with Idiopathic Pulmonary Fibrosis: A Phase 2, Double-Blind, Placebo-controlled Clinical Trial.

Abstract

<b>Rationale:</b> Idiopathic pulmonary fibrosis (IPF) is characterized by excessive deposition of type I collagen. ⁶⁸Ga-CBP8, a type I collagen positron emission tomography probe, measures collagen accumulation and shows higher collagen deposition in patients with IPF. Bexotegrast (PLN-74809) is an oral, once-daily, dual-selective inhibitor of α_vβ₆ and α_vβ₁ integrins under late-stage evaluation for treatment of IPF. <b>Objectives:</b> To evaluate changes in type I collagen in the lungs of participants with IPF after treatment with bexotegrast. <b>Methods:</b> In this phase 2 (NCT05621252), single-center, double-blind, placebo-controlled study, adults with IPF received bexotegrast 160 mg or placebo for 12 weeks. The primary endpoint was the change in whole-lung standardized uptake value of ⁶⁸Ga-CBP8 positron emission tomography. Changes in lung dynamic contrast-enhanced magnetic resonance imaging parameters, FVC, cough severity, and biomarkers of collagen synthesis and progressive disease were also assessed. <b>Measurements and Main Results:</b> Of 10 participants, 7 received bexotegrast and 3 received placebo. At Week 12, the mean change from baseline in the top quartile of ⁶⁸Ga-CBP8 whole-lung standardized uptake value was -1.2% with bexotegrast versus 6.6% with placebo; the greatest mean changes were observed in subpleural lung regions in both groups (bexotegrast, -3.7%; placebo, 10.3%). Dynamic contrast-enhanced magnetic resonance imaging showed numerically increased peak enhancement and faster contrast washout rate in bexotegrast-treated participants, suggesting improvements in lung microvasculature and decreased extravascular extracellular volume. Bexotegrast treatment resulted in numerical improvements in FVC, cough severity, and biomarkers. <b>Conclusions:</b> The reduced uptake of ⁶⁸Ga-CBP8 in the lungs of participants with IPF indicates an antifibrotic effect of bexotegrast, suggesting the potential for favorable lung remodeling. Clinical trial registered with www.clinicaltrials.gov (NCT05621252).