GRI Bio’s Tazarotene Shows Promise in Phase IIa IPF Trial

GRI Bio’s investigational therapy, tazarotene (GRI-0621), has demonstrated efficacy and safety in a US-based Phase IIa trial for idiopathic pulmonary fibrosis (IPF). The retinoic acid receptor beta and gamma (RAR-βɣ) dual agonist met primary and secondary endpoints and was well tolerated, with the most common adverse events being dry skin, dry lips, and joint pain. No increases in cough or gastrointestinal issues were observed compared with placebo over 12 weeks.

Tazarotene showed biomarker evidence of fibrosis resolution and alveolar repair. Patients on treatment had a 3% decrease in PRO-C6, a marker of type VI collagen synthesis, versus a 12% increase in placebo, alongside a 6% rise in the collagen degradation biomarker C6M. Type IV collagen synthesis (PRO-C4) increased 9% on treatment, suggesting basement membrane repair. Clinically, 39% of treated patients improved forced vital capacity (FVC), compared with 80% of placebo patients experiencing declines.

With analysts forecasting a potential 2029 launch and $283m in 2031 revenue, tazarotene could become a key entrant in the evolving IPF market.

19-12-2025