ACELYRIN, INC. Announces Positive Phase 1/2 Proof-of-Concept Data for Lonigutamab, First Subcutaneous Anti-IGF-1R to Demonstrate Clinical Responses in Thyroid Eye Disease

Rapid improvements demonstrated for proptosis, clinical activity scores, and diplopia versus placebo with a favorable safety profile

Phase 2b/3 trial to be initiated in the second half of 2024

Conference call to review these data to be held at 8:30 a.m. ET today

LOS ANGELES, March 20, 2024 (GLOBE NEWSWIRE) -- ACELYRIN, INC. (Nasdaq: SLRN), a late-stage clinical biopharma company focused on accelerating the development and delivery of transformative medicines in immunology, today 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.

“These results are the first reported clinical data for the anti-IGF-1R mechanism delivered subcutaneously and demonstrating clinical benefit in thyroid eye disease patients. The data support our hypothesis that lonigutamab has the potential to optimize benefit-risk by enabling longer-term subcutaneous dosing to increase depth and durability of clinical response while attempting to limit safety liabilities by avoiding the high maximal concentrations resulting from IV administration, while maintaining optimal therapeutic levels,” said Shao-Lee Lin, MD, PhD, Founder and CEO of ACELYRIN. “Tackling thyroid eye disease has special meaning for our team, and we are thankful to the patients and investigators who have partnered with us. We are delighted to have achieved proof of concept for lonigutamab in TED and intend to advance clinical development with the potential to move patients toward resolution of their disease.”

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.

Endpoint (% of patients achieving response at 6 weeks)		Cohort 1					Cohort 2
		Placebo