Spyre Therapeutics has initiated dosing in a healthy volunteer, Phase 1 clinical trial of its investigational half-life extended anti-IL-23 monoclonal antibody, SPY003. This milestone marks our fourth on-time clinical trial initiation in nine months.

"Recent third-party clinical data demonstrate that combination therapies that include an IL-23 antibody can produce superior results for IBD patients. We believe SPY003 has the potential to be a best-in-class IL-23 antibody and a compelling combination partner with our α4β7 and TL1A antibodies that can be delivered on a quarterly or bi-annual treatment schedule." said Deanna Nguyen, MD, SVP of Clinical Development at Spyre.

"We look forward to presenting the interim Phase 1 data in the second half of this year before adding SPY003 as the final monotherapy component of our planned Phase 2 platform trial in ulcerative colitis which will evaluate three investigational monotherapies and three investigational combination therapies," added Nguyen.

The SPY003 Phase 1 Trial (NCT06873724) is a double-blind, placebo-controlled single-ascending dose study in healthy volunteers. The study is expected to enroll approximately 56 healthy adult participants. The primary endpoint is safety, with pharmacokinetics (PK) serving as a secondary endpoint. Interim safety, PK, and ADA data from this trial are expected in the second half of 2025.

SPY003 is an investigational, novel, extended half-life monoclonal antibody targeting IL-23, being developed for the potential treatment of IBD. IBD is a chronic condition characterized by inflammation in the gastrointestinal tract and encompasses two main disorders: ulcerative colitis and Crohn's disease. In the United States, it is estimated that approximately 2.4 million individuals currently have IBD.

In head-to-head preclinical studies, SPY003 demonstrated equivalent potency to risankizumab in inhibiting pSTAT signaling and IL-17 production and exhibited significantly longer half-life in non-human primates with the potential to deliver dosing in humans as infrequently as once every six months.

A Phase 1 trial of SPY003 in healthy volunteers is ongoing, and the Company expects interim safety and pharmacokinetic data in the second half of 2025. Pending data from the Phase 1 trial, the company anticipates progressing into Phase 2 development.