BBI-801

BBI-801 is a potent and selective small molecule agonist of the retinoid X receptor (RXR), developed for the topical treatment of cutaneous T-cell lymphoma (CTCL). RXRs are nuclear receptors that function as ligand-activated transcription factors, playing a critical role in regulating cell proliferation, differentiation, and apoptosis. BBI-801 was designed to deliver therapeutic concentrations to skin lesions while maintaining low systemic exposure, thereby potentially avoiding the side effects associated with oral RXR agonists such as bexarotene (e.g., hypothyroidism and hypertriglyceridemia). The drug was being developed by Brickell Biotech (which later rebranded to Fresh Tracks Therapeutics), but development was halted as the company shifted its focus and eventually underwent liquidation in 2023.