This study includes a total of two parts, the first part is a double-blinded, placebo-controlled, multi-dose escalation study to evaluate the safety, preliminary efficacy and pharmacokinetic profiles after multiple doses in patients with moderate to severe psoriasis; the second part is a randomized, double-blinded, controlled study, with proposed high-, middle- and low-dose groups and placebo group based on the clinical effective dose determined in the first part, to evaluate the efficacy and safety of multiple doses of test drug in patients with moderate to severe psoriasis.~Part I of study (phase Ib):~A total of 4 dose groups are pre-specified in Part I of this study, i.e., 60 mg, 150 mg, 300 mg and 600 mg; multiple doses will be administered subcutaneously on abdomen. A total of 40 patients are planned to be enrolled, including 6 and 2 patients receiving test drug and placebo in 60 mg and 600 mg dose groups, respectively, 9 and 3 patients receiving test drug and placebo in the other two dose groups, respectively. Each patient can receive multiple doses at only one dose level.~Part II of study (phase II):~Based on the safety data of phase Ib study and the efficacy analysis of ER modeling, 300mg and 150mg of the test drug will be selected. A multi-center, double-blind, placebo-controlled phase II study was conducted. The patients will be radomized in a 1:1:1 ratio to receive 300mg, 150mg doses of the study drug or placebo. A total of 126 patients will be enrolled in phase II study, with 42 patients in each group. 300mg, 150mg doses of the study drug or placebo will be administered abdominal subcutaneously with multiple dosing. Each patient can receive multiple doses at only one dose level.
JS005-002 is a randomized, double-blinded, placebo-controlled phase Ib/II clinical study to evaluate the safety, tolerability, efficacy and pharmacokinetic profiles of multiple doses of JS005 (recombinant humanized anti-IL-17A monoclonal antibody) Injection in patients with moderate to severe psoriasis.