GRI Bio, Inc. GRI

We are a clinical-stage biopharmaceutical company focused on discovering, developing, and commercializing innovative therapies that target serious diseases associated with dysregulated immune responses leading to inflammatory, fibrotic and autoimmune disorders. Our goal is to be an industry leader in developing therapies to treat these diseases and to improve the lives of patients suffering from such diseases.

Our product candidate, GRI-0621, is an oral inhibitor of type 1 invariant Natural Killer T (iNKT) cells. The active pharmaceutical ingredient in GRI-0621, tazarotene, is a synthetic retinoid acid receptor-beta and gamma selective agonist. Tazarotene is approved in the United States for topical treatment of psoriasis and acne. While there are no approved oral formulations of tazarotene, as of December 31, 2025, it has been evaluated in over 1,700 patients as an oral product for up to 52-weeks. We are developing GRI-0621 for the treatment of severe fibrotic lung diseases such as idiopathic pulmonary fibrosis (IPF), a life-threatening progressive fibrotic disease of the lung that affects approximately 140,000 people in the United States, with up to 40,000 new cases per year in the United States. Some estimate that IPF affects 3 million globally. While there are currently two approved therapies for the treatment of lung fibrosis, neither has been associated with improvements in overall survival, and both therapies have been associated with significant side effects leading to poor therapeutic adherence. In preliminary and topline data from our trials to date with GRI-0621, and earlier trials with oral tazarotene, we have observed GRI-0621 to be well-tolerated and to inhibit iNKT cell activity in subjects. We and others have shown that activated iNKT are upregulated in IPF, primary sclerosing cholangitis (PSC), metabolic dysfunction-associated steatohepatitis (MASH), alcoholic liver disease (ALD), systemic lupus erythematosus (SLE), multiple sclerosis (MS), ulcerative colitis (UC) patients as well as other indications. In these patients activated iNKT cells are correlated with more severe disease.