Deucravacitinib, an oral selective tyrosine kinase 2 (TYK2) inhibitor, in patients with moderate to severe scalp psoriasis: efficacy and safety results of a phase 3b/4, multicenter, randomized, double-blinded, placebo-controlled trial (PSORIATYK SCALP)

Introduction: Deucravacitinib, an oral, selective, allosteric TYK2 inhibitor, is approved in multiple countries for treatment of adults with moderate to severe plaque psoriasis who are candidates for systemic therapy. PSORIATYK SCALP, an ongoing, 52-week, phase 3b/4, multicenter, randomized, double-blinded, placebo-controlled trial, evaluated deucravacitinib efficacy/safety in patients with moderate to severe scalp psoriasis, including those with more limited overall psoriasis. Methods: Adults with moderate to severe scalp psoriasis defined by more focused and objective inclusion criteria (ss-PGA =3, scalp surface area involvement =20%, and PSSI =12 at baseline) and BSA involvement =3% were randomized 1:2 to oral placebo or deucravacitinib 6 mg once daily through Week 16. The primary efficacy outcome was ss-PGA 0/1; key secondary outcomes were PSSI 90, change from baseline in scalp-specific itch numeric rating scale (NRS), and sPGA 0/1 at Week 16. Efficacy outcomes were evaluated at Week 16 for the overall population and the subpopulation with global sPGA =3. Nonresponder imputation and modified baseline observation carried forward were used for patients who discontinued or had missing data for binary and continuous outcomes, respectively. Results: 154 patients were randomized (placebo, n=51; deucravacitinib, n=103). Baseline characteristics were similar in each group (placebo: mean BSA 10.0%, PASI 9.4, PSSI 32.2; deucravacitinib: mean BSA 10.5%, PASI 10.2, PSSI 33.5). In the overall population, a higher proportion of patients receiving deucravacitinib versus placebo achieved ss-PGA 0/1 at Week 16 (48.5% vs 13.7%; P<0.0001). Deucravacitinib was superior to placebo for PSSI 90 (38.8% vs 2.0%; P<0.0001) and mean change from baseline in scalp-specific itch NRS (-3.2 vs -0.7; P<0.0001). In the subpopulation (sPGA =3), a greater proportion achieved sPGA 0/1 with deucravacitinib versus placebo (51.0% vs 4.3%; P<0.0001). The most common adverse events (AEs) in the deucravacitinib group (=5%) were nasopharyngitis (14.6%), upper respiratory tract infection (11.7%), acne (9.7%), headache (7.8%), COVID-19 (5.8%), and pustular acne (5.8%). Two serious AEs were reported (1/group); neither was considered treatment related or led to discontinuation. Conclusion: Deucravacitinib was efficacious and well tolerated in patients with moderate to severe scalp psoriasis, including those with less extensive overall psoriasis (BSA =3%). The overall psoriasis response rate (sPGA 0/1) was consistent with POETYK trial results, despite including patients with more limited BSA involvement. Safety findings were consistent with the known deucravacitinib safety profile.