ACELYRIN, INC. announced positive proof-of-concept data from an ongoing Phase 1/2 trial of lonigutamab in thyroid eye disease (TED). Lonigutamab is a subcutaneously (SC) delivered humanized IgG1 monoclonal antibody targeting the insulin-like growth factor-1 receptor (IGF-1R), a validated mechanism of action for the treatment for TED. In the Phase 1/2 trial, lonigutamab demonstrated rapid improvements in proptosis and clinical activity score (CAS) at the first measurement within three weeks after the first subcutaneous dose.

Lonigutamab Phase 1/2 Study Results: This multi-center, dose-ranging Phase 1/2 clinical trial is evaluating the safety and efficacy of lonigutamab dosed in TED patients. Cohort 1 was placebo-controlled with six patients receiving lonigutamab and two receiving placebo. Cohort 2 is open label with data available from six patients at six weeks.

Overall, lonigutamab has been well-tolerated across the company?s clinical experience to date. There have been no reports of hyperglycemia or hearing impairment and no serious adverse events. Next Steps: With proof of concept achieved in Cohort 1, and Cohort 2 further validating these results, a Phase 2b/3 trial is planned to be initiated in the second half of 2024, designed to be the first of two registrational trials in TED.