Efficacy of Deucravacitinib over time in Psoriasis by Baseline Total Body Surface Area: Post Hoc Analysis of the Randomized, Double-blind, Placebo-controlled Phase 3b/4 PSORIATYK SCALP Trial

Introduction: Deucravacitinib, an oral, selective, allosteric tyrosine kinase 2 (TYK2) inhibitor, is approved in multiple countries for treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy. In the phase 3b/4 PSORIATYK SCALP (NCT05478499) trial, deucravacitinib was superior to placebo at Week 16 in patients with moderate to severe scalp psoriasis, including those with more limited overall psoriasis. Here, we report efficacy of deucravacitinib in improving overall body psoriasis in patients with baseline total body surface area (BSA) involvement ≥3%, 3%-10%, and >10%. Methods: Outcomes were analyzed by baseline BSA involvement (BSA ≥3%, all randomized patients; BSA 3%-10% and BSA >10%, BSA-defined subgroups) through Week 16 and included static Physician Global Assessment score of 0 (clear) or 1 (almost clear) (sPGA 0/1), ≥75%/≥90% reduction from baseline in the Psoriasis Area and Severity Index (PASI 75/90), and adjusted mean percent change from baseline BSA. Analyses are post hoc; P values were obtained using a stratified Cochran-Mantel-Haenszel test, unstratified chi-squared test, or an analysis of covariance; all P values are nominal. Results: Overall (BSA ≥3%), 103 patients were assigned to deucravacitinib and 51 to placebo (n=70 vs n=38 [BSA 3%-10%] and n=33 vs n=13 [BSA >10%] for deucravacitinib versus placebo, respectively). Week 16 sPGA 0/1 response rates were higher for patients treated with deucravacitinib versus placebo overall (47.6% vs 3.9%; BSA ≥3%) and by BSA subgroups (42.9% vs 5.3% [BSA 3%-10%] and 57.6% vs 0% [BSA >10%]; all P<0.001). Week 16 PASI 75 response rates were also higher for patients treated with deucravacitinib versus placebo overall (42.7% vs 5.9% [BSA ≥3%]) and by BSA subgroups (34.3% vs 7.9% [BSA 3%-10%] and 60.6% vs 0% [BSA >10%]; all P<0.01). PASI 90 outcomes showed similar trends for deucravacitinib versus placebo. Patients treated with deucravacitinib had greater adjusted mean percent change from baseline in BSA score versus placebo overall (−43.4% vs +4.8% [BSA ≥3%]) and by BSA subgroups (−32.6% vs +3.4% [BSA 3%-10%] and −69.3% vs +9.5% [BSA >10%]; all P<0.05). Conclusion: In PSORIATYK SCALP, deucravacitinib improved overall psoriasis through Week 16 compared with placebo in patients with more limited overall psoriasis (BSA ≥3%) and in both subgroups (BSA 3%-10%, BSA >10%).