Equillium Hits Interim Enrollment in Phase 3 EQUATOR Study of Itolizumab for Acute Graft-Versus-Host Disease

Equillium, Inc., a clinical-stage biotechnology firm listed on Nasdaq, has reached a significant milestone in the Phase 3 EQUATOR study of itolizumab for acute graft-versus-host disease (aGVHD). This study has successfully met its interim enrollment target, involving over 100 patients across 12 countries. Equillium plans to present the interim data review to Ono Pharmaceutical Co. Ltd. in the third quarter, initiating a three-month period for Ono to decide whether to acquire Equillium's rights to the drug.

Bruce Steel, CEO of Equillium, praised the clinical development team's efforts in patient recruitment and trial site activation worldwide. The interim data will remain blinded to both Equillium and Ono, but an independent data monitoring committee will perform an unblinded analysis to determine whether the study should continue based on pre-set futility and efficacy criteria. With the enrollment threshold now achieved, Equillium is on track to meet the deadline for presenting this critical data milestone to Ono within the third quarter. Following the interim analysis, Ono will have three months to exercise its option to acquire itolizumab.

If Ono opts to acquire the rights, Equillium will receive a one-time payment of JPY 5.0 billion, approximately $32.2 million based on the May 8, 2024, exchange rate. Additionally, Equillium stands to earn up to $101.4 million upon hitting specific development, regulatory, and commercialization goals.

The EQUATOR study is a Phase 3, randomized, double-blind, placebo-controlled multicenter trial (NCT05263999). It evaluates the efficacy and safety of intravenous itolizumab versus placebo as a first-line treatment in about 200 adult and adolescent patients with Grade III-IV aGVHD or Grade II aGVHD with lower gastrointestinal involvement, in combination with high-dose corticosteroids. The study's primary endpoint is the complete response rate at Day 29, while key secondary endpoints include overall response rate at Day 29 and the durability of the complete response from Day 29 through Day 99.

Participants must start itolizumab treatment within three days of their first high-dose corticosteroid administration. The treatment period spans Days 1-99, with a follow-up period from Days 100-365. About 200 eligible patients will receive 2 mg/kg of methylprednisolone or an equivalent on Day 1 and will be randomized into two groups. Group A will receive an initial dose of 1.6 mg/kg of itolizumab, followed by six doses of 0.8 mg/kg every two weeks, along with systemic corticosteroids. Group B will receive a placebo alongside systemic corticosteroids. The independent data monitoring committee will conduct regular safety reviews and an interim analysis for both futility and efficacy after about 100 subjects have completed their Day 29 assessments.

Itolizumab is a first-in-class anti-CD6 monoclonal antibody that targets the CD6-ALCAM signaling pathway, selectively downregulating pathogenic T effector cells while preserving T regulatory cells, essential for maintaining immune balance. This pathway is crucial in modulating T cell activity and trafficking, which drive many immuno-inflammatory diseases.

Equillium is dedicated to developing novel therapeutics for severe autoimmune and inflammatory disorders. Its pipeline features EQ101, a selective tri-specific cytokine inhibitor targeting IL-2, IL-9, and IL-15, currently in Phase 2 trials for alopecia areata in Australia and New Zealand. EQ302 is an orally delivered bi-specific cytokine inhibitor targeting IL-15 and IL-21, currently in pre-clinical development. The company also has a multi-cytokine platform designed to selectively block key cytokines at the shared receptor level, targeting pathogenic cytokine redundancies, while preserving non-pathogenic signaling.

Equillium acquired rights to itolizumab through an exclusive partnership with Biocon Limited and has entered a strategic partnership with Ono for its development and commercialization.