GRI-0621

GRI-0621 is a small molecule RAR-beta/gamma (RAR-βɣ) dual agonist that inhibits the activity of human type 1 invariant natural killer T (iNKT) cells. It is being developed as an oral, once-daily therapeutic for idiopathic pulmonary fibrosis (IPF), a rare chronic progressive lung disease characterized by abnormal scarring and impaired oxygen transfer. By targeting iNKT cells upstream in the inflammatory cascade, GRI-0621 aims to reduce inflammation and fibrosis, potentially offering greater efficacy than current treatments. Preclinical and early clinical studies have shown that GRI-0621 improves fibrosis in multiple disease models and reduces liver function test abnormalities in patients. The drug has demonstrated a favorable safety profile in prior late-stage studies with no significant lipid changes or major safety concerns observed to date. Developed by GRI Bio, it is currently being evaluated in a Phase 2a biomarker study for IPF, with potential expansion into other fibrotic indications[1][2][3][5][6][7][8].