Efficacy of Deucravacitinib, an Oral, Selective, Allosteric Tyrosine Kinase 2 (TYK2) Inhibitor, in Scalp Psoriasis by Baseline Psoriasis Area and Severity Index (PASI) and Baseline Body Surface Area (BSA): A Subanalysis of the Phase 3 Clinical Trial Data

Introduction: Deucravacitinib, an oral, selective, allosteric TYK2 inhibitor, is approved in the US, EU, and other countries for treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy. Deucravacitinib was effective and well tolerated in the global, 52-week, phase 3 POETYK PSO-1 (NCT03624127) and POETYK PSO-2 (NCT03611751) trials. Here, efficacy of deucravacitinib in scalp psoriasis was evaluated by baseline severity of psoriasis in the trial patients with scalp involvement. Methods: Patients with moderate to severe scalp involvement (scalp-specific Physician Global Assessment [ss-PGA] ≥3) at baseline were included in this analysis. Efficacy outcomes (ss-PGA 0/1 and Psoriasis Scalp Severity Index [PSSI] 90) were reported through Week 24 (pooled PSO-1/PSO-2, before PSO-2 rerandomization, n=514) and Week 52 (PSO-1, continuous deucravacitinib treatment, n=192). Outcomes were stratified by baseline PASI score 12-<15 (low) or ≥15 (high) and baseline BSA involvement 10%-≤15% (low) or >15% (high). Results: ss-PGA 0/1 response rates were high and slightly greater in the high versus low PASI subgroup at Week 24 (65.8% and 58.3%, respectively) and Week 52 (73.5% and 60.0%). Similarly, PSSI 90 response rates were high and also somewhat greater in the high versus low PASI subgroup at Week 24 (55.3% and 45.8%) and Week 52 (66.0% and 53.3%). Across the 2 baseline BSA subgroups, ss-PGA 0/1 and PSSI 90 response rates were comparable at Weeks 24 and 52. Conclusion: Deucravacitinib treatment was effective in patients with scalp involvement in psoriasis regardless of overall baseline disease severity.