Ixekizumab 80 mg Every 2 Weeks Treatment Beyond Week 12 for Japanese Patients with Generalized Pustular Psoriasis and Erythrodermic Psoriasis

Introduction In 2018, ixekizumab (80 mg every 2 weeks [Q2W] beyond Week 12) received approval in Japan for patients with generalized pustular psoriasis (GPP) and erythrodermic psoriasis (EP). This open-label study evaluated the efficacy and safety of ixekizumab (80 mg Q2W from Week 12 to Week 20) in Japanese patients with GPP and EP. Methods Seven patients with GPP and five patients with EP were enrolled. An initial dose of 160 mg (subcutaneous [SC] injection) was followed by 80 mg Q2W SC until Week 12. Primary endpoint assessed global improvement score (GIS) by comparing psoriatic findings, Static Physician Global Assessment, Psoriasis Area and Severity Index score, and other evaluations with those at the baseline and were graded as 1 = resolved, 2= improved, 3 = unchanged, and 4 = worsened. Patients who showed GIS = 1 (resolved) at Week 12 completed the study. Patients with GIS ≥ 2 continued to receive ixekizumab 80 mg Q2W until Week 20. Results At Week 12, four of seven patients with GPP showed “resolved,” two showed “improved,” and one showed “worsened.” Of five patients with EP, one showed “resolved” and four showed “improved.” Two patients with GPP and four patients with EP continued ixekizumab treatment until Week 20. At Week 20, one of the two patients with GPP showed “resolved” and one patient showed “improved.” All four patients with EP showed “improved.” One non-drug related serious adverse event was reported by one patient with EP at Week 12. From Week 12 to Week 20, no adverse events (AEs) were reported in patients with GPP, but two mild AEs were reported in one of the four patients with EP. Conclusions This study indicates that ixekizumab continuous Q2W dosing is efficacious and safe for patients with GPP and EP. Clinical Trial Registration NCT03942042.