A Randomized, Double-blind, Placebo-controlled, Phase I Study of MEDI-545, an Anti-interferon-alfa Monoclonal Antibody, in Subjects with Chronic Psoriasis

Background: Interferon-alfa (IFN-alpha) has been implicated in the pathogenesis of psoriasis.

Objective: To evaluate the safety profile of MEDI-545, a fully human anti-IFN-alpha monoclonal antibody and to explore its effect on the involvement of type I IFN-alpha activity in the maintenance of established plaque psoriasis.

Methods: We conducted an 18-week, randomized, double-blind, placebo-controlled, dose-escalating study in 36 subjects with chronic plaque psoriasis. Subjects received one intravenous dose of MEDI-545 (0.3-30.0 mg/kg) or placebo. Study outcomes were safety profile, pharmacokinetics, immunogenicity, and clinical effects.

Results: There was no difference in adverse events between MEDI-545 and placebo. Two serious adverse events were reported; one drug-related hypotensive infusion reaction occurred in one subject in the 30.0 mg/kg MEDI-545 dose group, causing discontinuation of study drug in that subject and study dismissal of the other subjects in the same cohort; and a myocardial infarction occurred in one subject in the 10 mg/kg MEDI-545 dose group, which was considered to be unrelated to treatment. MEDI-545 was nonimmunogenic, had a half-life of 21 days, showed no significant inhibition of the type I IFN gene signature, and had no clinical activity.

Limitations: The study addressed only IFN-alpha and chronic psoriatic lesions.

Conclusion: The safety profile of MEDI-545 supports further clinical development. IFN-alpha does not appear to be significantly involved in the maintenance of established plaque psoriasis.