OBJECTIVES : Predicting treatment response early on is important in psoriasis management. Tildrakizumab – an IL-23 inhibitor – is approved for the treatment of adult patients with moderate-to-severe plaque psoriasis. The differences in Psoriasis Area Severity Index (PASI) improvement from baseline among tildrakizumab non-responders (PASI <50), partial responders (PASI 50-74), responders (PASI ≥75), and super responders (PASI ≥90) are observed as early as week 4. This analysis evaluated whether an early PASI improvement (i.e. week 4 or 16) could potentially predict week-28 PASI response status.

METHODS : Patients from two tildrakizumab phase-3 trials (reSURFACE 1 [NCT01722331] and reSURFACE 2 [NCT01729754]) who were randomized to receive tildrakizumab 100 mg at weeks 0, 4, 16 and 28 were included in this pooled analysis. Week 4 and 16 PASI cutoff (PASI <50 or PASI ≥50) were used to predict the week-28 PASI responder, super responder and non-responder status, and positive predictive value (PPV) and negative predictive value (NPV) were reported.

RESULTS : This analysis included 574 patients (mean age: 45.6 years; male: 69.5%), with 8.3%, 77.4%, and 53.5% achieving PASI <50, PASI ≥75, and PASI ≥90 at week 28, respectively. At week 4, 231 (41%) patients achieved PASI ≥50, and the PPV and NPV were 87.0% and 29.2% for predicting week-28 responders and 66.7% and 55.1% for predicting week-28 super responders, respectively. At week 16, 66 (11.5%) patients achieved PASI <50, and the PPV and NPV were 84.8% and 85.5% for predicting week-28 PASI <75, respectively.

CONCLUSIONS : Among patients with moderate-to-severe psoriasis, the majority of tildrakizumab-treated patients became PASI responders at week 28. Over 40% of patients achieved PASI ≥50 at week 4, which was predictive of week-28 PASI response or even super response. By week 16, few patients achieved PASI <50 and the majority of them did not become responders at week 28.