SPY003

SPY003 is a novel, half-life extended monoclonal antibody (mAb) designed to selectively bind the p19 subunit of interleukin-23 (IL-23p19). It is engineered for high potency and selectivity, with a pharmacokinetic profile that enables infrequent dosing—potentially quarterly or twice yearly—as maintenance therapy. Preclinical data show that SPY003 has in vitro potency comparable to risankizumab and a half-life of approximately 30 days in non-human primates, more than three times longer than risankizumab. The drug potently inhibits downstream cellular signaling by targeting IL-23, an established pathway in inflammatory bowel disease (IBD). Its primary clinical development focus is on moderate-to-severe ulcerative colitis and Crohn’s disease. Spyre Therapeutics is developing this agent as part of its portfolio of next-generation IBD therapies, including rational combinations with other proprietary antibodies[1][3][6][8].