Pharmacokinetics and Safety of Icotinib Hydrochloride Cream in Patients with Mild to Moderate Chronic Plaque Psoriasis: A Randomized Double-Blind Vehicle-Controlled Phase 1 Study

Objective. This phase I study aimed to systematically assess the safety, local tolerability, pharmacokinetics, and preliminary efficacy of topical icotinib hydrochloride cream in patients with mild to moderate plaque psoriasis. Materials and Methods. Eligible Chinese adult patients with mild to moderate psoriasis were assigned to the icotinib cream or vehicle group. Icotinib cream with increasing concentrations (0.5%, 1.0%, 2.0%, and 4.0%) or vehicle were administered by the fingertip unit method to the skin lesions twice a day for 4 weeks. Safety assessments included the incidence and severity of adverse events (AEs), local tolerability at the treatment area, vital signs, and laboratory examinations. Plasma levels of icotinib were also measured for the pharmacokinetics calculation. The efficacy was preliminarily explored by assessing the improvement in the severity level using Target Plaque Severity Score (TPSS) and overall improvement using the Psoriasis Area Severity Index (PASI) and Dermatological Quality Life Index. Results. Forty-one patients were enrolled and qualified for safety analysis. 27 (65.9%) patients experienced at least one AE, of which application-site adverse drug reactions (ADRs) were reported in 6 (14.6%) patients. All ADRs were of grade 1 or 2, most common irritation (4.5%), itching (3.1%), and erythema (2.4%), and resolved during follow-up. The systemic exposure to icotinib was very low; the highest plasma concentration was 0.214 ng/mL, while the area under the curve from 0 to 12 hours was 1.626 h·ng/mL. The TPSS improved for all icotinib groups after treatment in a dose- and time-dependent manner. Conclusion. This phase 1 study demonstrated favorable safety, tolerable toxicity, and preliminary efficacy of icotinib cream in patients with mild to moderate psoriasis. The dose concentration of 2.0% (twice daily based on the fingertip unit method) is recommended for further study. Study Design. This is a single-center, randomized, double-blind, and vehicle-controlled study.