Investigation of plaque psoriasis relapse after secukinumab withdrawal in patients from two phase III studies

Background Secukinumab is effective against a range of psoriatic manifestations. Investigating psoriasis (PsO) relapse following secukinumab discontinuation could provide insights into long-term PsO remission. Objectives To examine PsO relapse rates on treatment discontinuation following 1 year of secukinumab treatment. Methods This study (clinical trial number: NCT01544595) is an extension of the phase III ERASURE/FIXTURE studies in patients with moderate-to-severe plaque PsO. After 1 year of secukinumab 300 mg or 150 mg treatment, participants who had responded to treatment with a ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) at week 52 were randomly assigned to receive placebo (n=120 and n=100, respectively). On relapse, patients receiving placebo were switched to their previous secukinumab dose. The study primary outcome was the nonrelapse rate after secukinumab withdrawal. Results Following the last dose of secukinumab 300 mg, 20.8% (25/120) and 10.0% (12/120) of patients who switched to placebo did not relapse at 1 and 2 years after discontinuation, respectively. Patients who received secukinumab 150 mg for 1 year showed a lower proportion of nonrelapse following treatment discontinuation [14% (14/100) and 6% (6/100)] at 1 and 2 years, respectively. Patients who did not relapse maintained low mean PASI (2.8) at 1 year drug free vs. baseline (20.9); 1.7 at 2 years drug free vs. baseline (19.2), following an initial 52-week treatment with secukinumab 300 mg. Disease duration (P=0.02) and severity (P=0.02) were significantly associated with time to relapse in patients initially treated with secukinumab 300 mg; patients with shorter disease duration and lower baseline PASI remained relapse-free for longer. Conclusions Following discontinuation of secukinumab, a proportion of patients stayed relapse-free. Further, patients with shorter disease duration remained relapse-free for longer, suggesting that earlier treatment with secukinumab may result in long-term clinical control of moderate-to-severe PsO.