A Phase Ⅲ Efficacy and Safety Study of Hemay005 in Subjects With Moderate to Severe Plaque Psoriasis

Hemay005 is a novel phosphodiesterase type 4(PDE4) inhibitor being developed for the treatment of psoriasis. After single asending dose and mutiple asending dose in health subjects. phase 2 results suggest Hemay005 60 mg BID has a higher curative effect trend，and adverse reactions were mild, so we choose 60 mg BID as Hemay005 phase 3 dosage And the patients with moderate to severe plaque psoriasis will be randomized into 2 cohorts(60mg BID and placebo) approximately 306 subjects will be enrolled (204 in 60mg BID and 102 in placebo). This study includes an 16-week treatment Period, then a 36-week Treatment Period without placebo.