Time to relapse after tildrakizumab withdrawal in patients with moderate-to-severe psoriasis who were responders at week 28: post hoc analysis through 64 weeks from reSURFACE 1 trial

Background As treatment interruptions occur during psoriasis management in clinical practice, it is important to know the duration of clinical response after treatment withdrawal. Objectives To report time to and predictors of relapse in patients who were tildrakizumab 100 and 200 mg responders (>= 75% improvement in Psoriasis Area and Severity Index, PASI 75) at week 28 re-randomized to placebo from reSURFACE 1 trial. Methods Post hoc analysis of adult patients with moderate-to-severe plaque psoriasis from a 64-week phase 3 trial. Relapse was primarily defined as loss of PASI 75 response. Both relapses defined as loss of PASI 90 and loss of absolute PASI < 2 response were included as sensitivity analyses. PASI 75, PASI 90 and PASI < 2 responders re-randomized to placebo at week 28 and followed up until week 64 were included. The Kaplan-Meier (KM) estimates of the 64-week relapse rate were calculated. The log-rank test to compare KM curves from responders to tildrakizumab 100 and 200 mg was used. Independent predictors of relapse were explored. Results Median time to loss of PASI 75/PASI 90/PASI < 2 response from week 28 was 142/111/112 days with tildrakizumab 100 mg and 172/140/113 days with tildrakizumab 200 mg, respectively (all not significant). Around 20% of patients did not relapse (either maintained a PASI 75 response or were lost to follow-up) during the 36-week period. Increase in body mass index (BMI) (hazard ratio, HR [95% confidence interval, CI] for loss of PASI 75 response: 1.0345 [1.0112-1.0582]) and increase in disease duration (HR [95% CI]: 1.0151 [1.0028-1.0275] for loss of PASI 75 response) were associated with an increased risk of relapse, regardless of the relapse definition. Conclusions When treatment is interrupted, tildrakizumab provides durable maintenance of efficacy with a median time to loss of PASI 75 response of 5-6 months, irrespective of the dose. Interventions on modifiable risk factors for relapse, such as BMI, may improve personalized long-term psoriasis management.