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.