The Phase 3, randomized, double-blind, placebo-controlled multicenter study compared the efficacy and safety of intravenous administered itolizumab versus placebo (randomized 1:1) as a first-line therapy in 158 adult and adolescent patients with Grade III-IV aGVHD, or Grade II aGVHD with lower gastrointestinal involvement, in combination with high doses of corticosteroids, the current standard of care. The primary study endpoint was complete response rate (CR) at Day 29; key secondary endpoints included overall response rate (ORR) at Day 29 and rate of durable CR from Day 29 through Day 99. Additional secondary outcomes included CR at Day 99, duration of CR, failure free survival, and overall survival.

Per the study protocol, patients received itolizumab within 3-days of the first administration of high-dose corticosteroids with a treatment period from Days 1-99, and a follow-up period from Days 100-365. Subjects received 2 mg/kg methylprednisolone or equivalent on Day 1 and were randomized in a 1:1 ratio to the following two treatment groups:

• Group A: Itolizumab, 1.6 mg/kg initial dose followed by 6 doses of 0.8 mg/kg once every 2 weeks (q2w), plus systemic corticosteroids (79 subjects)
• Group B: Placebo, 7 doses every other week, plus systemic corticosteroids (79 subjects)

The EQUATOR study remains ongoing with all patients having completed dosing, and 30 patients in the follow-up period per protocol. An independent data monitoring committee oversees the study and regularly reviews safety data.