Spyre Therapeutics Inc.SPY003 hit its Phase 2 primary endpoint, completing proof-of-concept for all three IBD monotherapy molecules.

Spyre Therapeutics announced on September 8 that SPY003, its anti-IL-23 antibody, hit its primary endpoint in Part A of the Phase 2 SKYLINE trial, posting a 10.0-point reduction in Robart's Histopathology Index score at Week 12 with a p-value below 0.0001. The result completes proof-of-concept for all three molecules behind the company's inflammatory bowel disease combination strategy, following SPY001 and SPY002, which posted RHI reductions of 9.2 points and 10.7 points respectively in the same open-label monotherapy portion of the trial. SPY003 delivered a 20% clinical remission rate and 30% endoscopic improvement, while SPY001 and SPY002 posted remission rates of 40% and 33%, and all three monotherapies were described as well tolerated. Spyre held $1.1 billion in cash, cash equivalents, and marketable securities as of June 30, a position built in part on a $435.2 million stock offering in April, which management says funds operations into the second half of 2029. The combination thesis remains unproven: Part B, which tests the pairwise combinations SPY120, SPY130, and SPY230 against placebo, is still enrolling, with topline induction data not expected until 2027, while the company used $69.9 million in operating activities in the second quarter of 2026 and posted a net loss of $36.2 million.
Spyre Therapeutics Inc.SPY003 hit its Phase 2 primary endpoint, completing proof-of-concept for all three IBD monotherapy molecules.