GRI Bio Plans 52-Week Study Of GRI-0621 Following Phase 2a IPF Data
(RTTNews) - GRI Bio, Inc. (GRI) announced new Phase 2a data from its GRI-0621-IPF-02 study evaluating oral GRI-0621 in patients with idiopathic pulmonary fibrosis (IPF).
The data, presented at the 2026 European Respiratory Society (ERS) Congress, integrated whole-blood RNA sequencing, serum extracellular matrix biomarkers, spectral flow cytometry and clinical readouts from the same 35-patient study population.
The findings identified consistent signals across nine pre-specified mechanistic pillars, including immune re-balancing, reduced lung injury, myofibroblast inhibition, fibrolysis, basement-membrane repair, re-epithelialization, FVC stabilization, antitussive effect and gastrointestinal protection.
GRI-0621 is an oral retinoic acid receptor (RAR) beta/gamma-selective agonist designed to modulate pathways associated with inflammation, fibrosis and tissue repair.
Whole-blood RNA sequencing identified 18 statistically significant anchor transcripts, while 13 spectral flow cytometry readouts reached statistical significance.
The biomarker findings indicated suppression of pro-fibrotic Th2 signaling and the TGF-beta and ROCK2 pathways, along with increased collagen degradation and reduced collagen synthesis, supporting a potential anti-fibrotic effect.
The study also showed signals consistent with basement-membrane repair and alveolar epithelial re-epithelialization, including changes in genes associated with type 2 and type 1 alveolar epithelial cell function.
At Week 12, 39% of patients receiving GRI-0621 experienced an FVC increase of at least 30 mL compared with 20% for placebo.
The proportion increased to 50% among patients receiving background standard-of-care antifibrotic therapy.
Only 8% of GRI-0621-treated patients experienced an FVC decline of at least 10%, compared with 20% for placebo.
Placebo-adjusted FVC change from baseline at Week 12 was +99 mL overall and +139 mL among patients receiving background standard-of-care antifibrotic therapy.
Ten post hoc sensitivity analyses of the exploratory FVC endpoint remained directionally positive, with estimates ranging from +40 to +65 mL overall and +67 to +89 mL among patients receiving background standard-of-care therapy.
GRI-0621 was well tolerated over the 12-week study period.
No serious treatment-emergent adverse events were reported in the GRI-0621 arm compared with 8% for placebo, and there were no drug-related serious adverse events.
Treatment-emergent cough, dyspnea and diarrhea were reported less frequently with GRI-0621 than placebo, at 0% versus 25%, 4% versus 17% and 17% versus 33%, respectively.
The randomized, double-blind, placebo-controlled Phase 2a study enrolled 35 patients with IPF who were randomized 2:1 to receive GRI-0621 4.5 mg once daily or placebo for 12 weeks.
Approximately 80% of participants received background pirfenidone or nintedanib.
GRI Bio said the totality of the Phase 2a findings supports advancing GRI-0621 into a longer-duration study, including evaluation over 52 weeks in combination with background pirfenidone or nintedanib.
GRI Bio is a clinical-stage biopharmaceutical company developing therapies for inflammatory, fibrotic and autoimmune diseases.
Its lead program, GRI-0621, is being developed as a potential oral treatment for IPF, while the company also has a pipeline of type 2 diverse NKT agonists for systemic lupus erythematosus.
Currently, GRI is trading at $2.14, down 25.13%.
