Efficacy, Safety and Pharmacokinetics of IL-17 Monoclonal Antibody Injection (AK111) in Patients with Moderate-to-Severe Plaque Psoriasis: A Randomized, Double-Blinded, Placebo-Controlled Phase Ib Multidose Escalation Clinical Study

Objectives To evaluate the safety, tolerability, immunogenicity, and induced expression of skin biomarkers of AK111 injection after multiple administrations in subjects with moderate-to-severe plaque psoriasis. Methods This study is a randomized, double-blinded, placebo-parallel-controlled study using a dose escalation mode of multiple doses. A total of 48 subjects were sequentially randomized to receive each AK111 dose regimen (75 mg, 150 mg, 300 mg, 450 mg) or the corresponding placebo. All subjects were treated with the study drug at weeks 0, 1, 4, and 8 and were unblinded at week 12, with the placebo group ending and the AK111 group being followed up to 20 weeks. Results At week 12, compared with placebo, the percentage of subjects achieving Psoriasis Area and Severity Index 75 (PASI75) and static Physician Global Assessment (sPGA) 0/1 in the AK111 75 mg–450 mg dose groups was significantly increased, and higher PASI90 was achieved in the 150 mg, 300 mg, and 450 mg dose groups than in the 75 mg group. All efficacy indicators were maintained at week 20. The incidence of treatment-emergent anti-drug antibodies (ADAs) was 0% (0/48). Neutralizing antibodies (NAbs) were not detected in any subject. The proportion of subjects who reported any treatment-emergent adverse event (TEAE) was 75.0% in the AK111 group, similar to the 66.7% in the placebo group. The most commonly reported adverse events were hyperglycemia, elevated blood pressure, and hypokalemia. The AK111 pharmacokinetics showed approximate dose proportionality with regard to the maximum observed concentration ( C max ) and area under the curve from 0 to the time of the last quantifiable concentration (AUC 0– t ) following subcutaneous injection doses of 150–450 mg. Conclusions After moderate-to-severe plaque psoriasis subjects received multiple subcutaneous AK111 injections of 150–450 mg, AK111 exposure increased in a roughly dose-proportional relationship. AK111 was safe and tolerable. In subjects with moderate-to-severe plaque psoriasis, AK111 demonstrated encouraging preliminary efficacy, which was sustained for a relatively long time after the last dose administration. Clinical trial registration The clinical trial identification number is NCT05504317.