Background: Patients with psoriasis report impaired health-related quality of life (HRQoL; Dermatology Life Quality Index score ≥ 2) even after achieving clear or almost-clear skin with biologic treatment., Objective: To assess the effectiveness of brodalumab in HRQoL improvement and the factors associated with incomplete HRQoL improvement in Japanese patients with psoriasis., Methods: As a part of the single-arm, open-label, multicenter, prospective ProLOGUE study (Japan Registry of Clinical Trials identifier: jRCTs031180037), patients were treated with 210 mg of subcutaneous brodalumab in daily clinical practice until week 48. The absolute Psoriasis Area and Severity Index scores and patient-reported outcomes were assessed at baseline and weeks 12 and 48., Results: Seventy-three patients (male, 82.2%; median age, 54.0 years) were enrolled. The Dermatology Life Quality Index and European Quality of Life 5-Dimension 5-Level Utility Index scores significantly improved from baseline to weeks 12 and 48. At week 48, all 13 patients with a Dermatology Life Quality Index score of ≥2 and an absolute Psoriasis Area and Severity Index score of 0 to ≤2 reported itching., Limitations: Unclear generalizability of the results to other biologics., Conclusion: Treatment with brodalumab improved HRQoL in patients with psoriasis. Itching may contribute to incomplete HRQoL improvement in patients who have achieved clear or almost-clear skin., Competing Interests: Dr Miyagi reports financial support from Kyowa Kirin during the conduct of the study; is a consultant or advisor for AbbVie and Janssen Pharmaceuticals; has received funding or grants from AbbVie, Eisai, and Taiho Pharmaceutical; has received speaking and lecture fees from AbbVie, Janssen Pharmaceuticals, Maruho, Novartis Pharma, Boehringer Ingelheim, Eisai, Eli Lily Japan, CSL Behring, Taiho Pharmaceutical, Ono Pharmaceutical, Otsuka Pharmaceutical, and LEO Pharma; and has received travel reimbursement from AbbVie, Janssen Pharmaceuticals, Maruho, Novartis Pharma, Taiho Pharmaceutical, and Ono Pharmaceutical outside the submitted work. Dr Kanai is an employee of Kyowa Kirin. Dr Murotani reports financial support from Kyowa Kirin during the conduct of the study. Dr Okubo reports financial support from Kyowa Kirin during the conduct of the study; is a consultant or advisor for AbbVie, Amgen, Boehringer Ingelheim, Kyowa Kirin, Sun Pharma, UCB Pharma, Taiho Pharmaceutical, Eli Lilly Japan, Novartis Pharma, Maruho, LEO Pharma, and Janssen Pharmaceuticals; has received funding or grants from AbbVie, Eisai, Kaken Pharmaceutical, Kyowa Kirin, GlaxoSmithKline Shiseido, Sun Pharma, JIMRO, Taiho Pharmaceutical, Torii Pharmaceutical, Eli Lilly Japan, Novartis Pharma, Maruho, LEO Pharma, and Janssen Pharmaceuticals; and has received speaking and lecture fees from AbbVie, Amgen, Boehringer Ingelheim, Eisai, Kyowa Kirin, Sanofi, Sun Pharma, UCB Pharma, JIMRO, Taiho Pharmaceutical, Mitsubishi Tanabe Pharma, Torii Pharmaceutical, Eli Lilly Japan, Novartis Pharma, Maruho, LEO Pharma, Celgene, and Janssen Pharmaceuticals outside the submitted work. Dr Honna reports financial support from Kyowa Kirin during the conduct of the study; has received funding or grants from Kyowa Kirin and Eli Lilly Japan; and has received speaking and lecture fees from Kyowa Kirin, Novartis Pharma, Maruho, Eisai, Janssen Pharmaceuticals, Taiho Pharmaceutical, Mitsubishi Tanabe Pharma, AbbVie, Torii Pharmaceutical, Eli Lilly Japan, Sun Pharma, and Celgene outside the submitted work. Dr Kobayashi reports statistical analysis support and writing assistance from Kyowa Kirin during the conduct of the study and has received speaking and lecture fees from Janssen Pharmaceuticals and Taiho Pharmaceutical outside the submitted work. Dr Seishima reports financial support from Kyowa Kirin during the conduct of the study; has received funding or grants from Taiho Pharmaceutical, Novartis Pharma, Sanofi, Maruho, Mitsubishi Tanabe Pharma, Kyowa Kirin, Sun Pharma, Kaken Pharmaceutical, Japan Blood Products Organisation, Eisai, and Torii Pharmaceutical; has received speaking and lecture fees from Taiho Pharmaceutical, Novartis Pharma, Sanofi, Maruho, Eli Lilly Japan, Mitsubishi Tanabe Pharma, Kyowa Kirin, Sun Pharma, Kaken Pharmaceutical, LEO Pharma, Celgene, Janssen Pharmaceuticals, Eisai, AbbVie, Torii Pharmaceutical, and JIMRO; and has received travel reimbursement from Taiho Pharmaceutical, Novartis Pharma, Sanofi, Maruho, Eli Lilly Japan, Mitsubishi Tanabe Pharma, Kyowa Kirin, Sun Pharma, Kaken Pharmaceutical, Japan Blood Products Organisation, LEO Pharma, Celgene, Janssen Pharmaceuticals, Pola Pharma, Eisai, AbbVie, Torii Pharmaceutical, and JIMRO outside the submitted work. Dr Mizutani reports financial support, article publishing charges, statistical analysis support, and writing assistance from Kyowa Kirin during the conduct of the study and has received speaking and lecture fees from Taiho Pharmaceutical, Novartis Pharma, Sanofi, Maruho, Eli Lilly Japan, Mitsubishi Tanabe Pharma, Sun Pharma, Kaken Pharmaceutical, Japan Blood Products Organisation, and Kyowa Kirin outside the submitted work. Author Kitabayashi is an employee of Kyowa Kirin and owns stock in the company. Dr Imafuku reports financial support from Kyowa Kirin during the conduct of the study; has received speaking and lecture fees from Astellas Pharma, AbbVie, Eli Lilly Japan, Otsuka Pharmaceutical, Kaken Pharmaceutical, Sato Pharmaceutical, Sanofi, Sun Pharma, GlaxoSmithKline, Celgene, Daiichi Sankyo, Takeda Pharmaceutical, Taiho Pharmaceutical, Mitsubishi Tanabe Pharma, Tsumura, Torii Pharmaceutical, Nippon Zoki Pharmaceutical, Novartis Pharma, Pfizer, Bristol Myers Squibb, Maruho LEO Pharma, Janssen Pharmaceuticals, and UCB Japan; has received funding or grants from AbbVie, Eisai, Sato Pharmaceutical, Sun Pharma, Taiho Pharmaceutical, Mitsubishi Tanabe Pharma, Tsumura, Maruho, and LEO Pharma; and is a consultant or advisor for Bristol, Meiji Seika Pharma, and LEO Pharma outside the submitted work., (© 2022 by the American Academy of Dermatology, Inc. Published by Elsevier Inc.)