Extension of Secukinumab and Ixekizumab Dose for Moderate-To-Severe Psoriasis in Low Disease Activity Intervals

Biological agents targeting IL-17A, such as secukinumab and ixekizumab, are highly effective in treating psoriasis, often achieving low disease activity or remission. However, frequent injections, side effects and high costs pose significant challenges. Extending dosing intervals for patients with stable disease and partial response may address these issues while maintaining efficacy, yet standardised dose reduction guidelines remain absent. This study aimed to evaluate the efficacy and safety of reduced dosing regimens of secukinumab and ixekizumab during the maintenance phase of psoriasis treatment. From 2020 to 2023, patients completing induction and maintenance phases with prescribed regimens, achieving a PASI (Psoriasis Area and Severity Index) score below 1 and PASI90 or PASI100 response, underwent clinician evaluations for extended dosing intervals. Secukinumab dosing was adjusted from 300 mg (or 150 mg) Q4W to Q8W, and ixekizumab from 80 mg Q4W to Q8W. Patients were monitored over 36 weeks, with data collected throughout the observation period to assess feasibility and safety. A total of 64 patients with moderate-to-severe plaque psoriasis were enrolled. Following extended dosing intervals, 75.4% maintained a PASI90 response at 12 weeks, with 67.7% sustaining it at 36 weeks. Similarly, 69.8% achieved PASI100 at 12 weeks, and 61.2% maintained this response at 36 weeks. These findings demonstrate that dose reduction strategies for secukinumab and ixekizumab in moderate-to-severe psoriasis can reduce treatment burden while maintaining high therapeutic efficacy, offering valuable insights to guide clinical guidelines and address current knowledge gaps.