Background: Tirabrutinib, a second-generation inhibitor of Bruton's tyrosine kinase, was approved in March 2020 for the treatment of relapsed or refractory primary central nervous system lymphoma (r/r PCNSL) based on phase I/II studies in Japan. We previously reported the overall response rate and safety profile. We describe Karnofsky Performance Status (KPS) and the quality of life (QoL) in patients with r/r PCNSL receiving tirabrutinib based on more than 1-year follow-up data., Methods: Patients with r/r PCNSL, age ≥20 years, and KPS ≥70 were treated with tirabrutinib once daily at a dose of 320, 480, or 480 mg under fasted conditions. QoL was assessed using questionnaires issued by the European Organization for Research and Treatment of Cancer (EORTC), namely EORTC QLQ-C30, EORTC QLQ-BN20, and EuroQol 5 dimensions 3-level (EQ-5D-3L) along with KPS., Results: Forty-four patients (mean age, 60 years [range 29-86]) were enrolled. The median follow-up period was 14.9 months (range, 1.4-27.7). The median KPS of the patients at baseline was 80.0 (range, 70-100), and this remained constant during the treatment. The global health status/QoL in the QLQ-C30 showed significant improvements from baseline through cycles 3-17 and remained relatively constant thereafter until cycle 23. Improvements were also seen in emotional functioning and constipation in the QLQ-C30 segments. Other items of QLQ-C30 and QLQ-BN20, EQ-5D visual analog scales, and EQ-5D index were maintained during the treatment., Conclusions: Tirabrutinib generally maintains KPS and QoL scores with some improvements in specific QoL items in patients with r/r PCNSL., Competing Interests: Y.A. received research grants from Ono Pharmaceutical Co. Ltd., Eisai Co., Ltd., Sanofi, Stryker, Taiho Pharmaceutical Co., Ltd., Daiichi-Sankyo, Japan Blood Products Organization, Philips., Nihon Medi-Physics Co., Ltd., Astellas Pharma Inc., Sumitomo Pharma Co., Ltd., Chugai Pharmaceutical Co., Ltd., Otsuka Pharmaceutical Co., Ltd.; payment honoraria from Nippon Kayaku Co., Ltd., Novocure, Daiichi-Sankyo, Ono Pharmaceutical Co., Ltd., Merck, Eisai Co., Ltd., UCB Japan Co., Ltd., Brainlab, Chugai Pharmaceutical Co., Ltd., Carl Zeiss, Nihon Medi-Physics Co., Ltd.; medical writing and article processing charges fees from Ono Pharmaceutical Co. Ltd. Y.N. received research grants from Ono Pharmaceutical Co. Ltd., Eisai Co., Ltd., Taiho Pharmaceutical Co., Ltd., Daiichi-Sankyo, Sumitomo Pharma Co., Ltd., Ohara Pharmaceutical Co., Ltd.; consulting fees form Sumitomo Pharma Co., Ltd.; payment honoraria from Chugai Pharmaceutical Co., Ltd., Ono Pharmaceutical Co. Ltd., Eisai Co., Ltd., Daiichi-Sankyo, Sumitomo Pharma Co., Ltd., Novocure; medical writing and article processing charges fees from Ono Pharmaceutical Co. Ltd. M.N. received research grants from Ono Pharmaceutical Co. Ltd., AbbVie, Daiichi-Sankyo, Kyowa Kirin, Eisai Co., Ltd., Mitsubishi Tanabe Pharma, Shionogi & Co., Ltd., Chugai Pharmaceutical Co., Ltd., Otsuka Pharmaceutical Co., Ltd., Nippon Kayaku Co., Ltd., Bayer, Teijin Pharma, Asahi Kasei Medical Co., Ltd.; consulting fees form Ono Pharmaceutical Co. Ltd., Novocure; meeting support form Ono Pharmaceutical Co. Ltd., Nippon Kayaku Co., Ltd., Ohara Pharmaceutical Co., Ltd., Eisai Co., Ltd., Denka Co., Ltd.; ad board advisory, medical writing and article processing charges form Ono Pharmaceutical Co. Ltd.; payment honoraria from Chugai Pharmaceutical Co., Ltd., Ono Pharmaceutical Co. Ltd., Eisai Co., Ltd., Kyowa Kirin, Daiichi-Sankyo, Sumitomo Pharma Co., Ltd., Novocure, Nippon Kayaku Co., Ltd., Ohara Pharmaceutical Co., Ltd., UCB Japan Co., Ltd.; medical writing fees from Chugai Pharmaceutical Co., Ltd. K.M. received research grants from Ono Pharmaceutical Co. Ltd., MSD, Eisai Co., Ltd., Teijin, Daiichi-Sankyo, Nihon Medi-Physics, Chugai Pharmaceutical Co., Ltd., Otsuka Pharmaceutical Co., Ltd., AbbVie, Medical U and A; payment honoraria from Ono Pharmaceutical Co., Ltd., Eisai Co., Ltd., Chugai Pharmaceutical Co., Ltd.; medical writing and article processing charges fees from Ono Pharmaceutical Co. Ltd. Y.T. received research grants Ono Pharmaceutical Co. Ltd.; payment honoraria from Eisai Co., Ltd., Celgene Corp., Ono Pharmaceutical Co. Ltd., Janssen, Chugai Pharmaceutical Co., Ltd., Abbvie, Symbio; medical writing and article processing charges fees from Ono Pharmaceutical Co. Ltd. N.F. received research grants Ono Pharmaceutical Co. Ltd.; Bayer, Chugai Pharmaceutical Co., Ltd., Celgene Corp., Genmab, Incyte; payment honoraria from AstraZeneca, BMS, Chugai Pharmaceutical Co., Ltd., CSL Behring, Dainippon Sumitomo, Eisai Co., Ltd., Janssen, Kyowa Kirin, Nippon Shinyaku, Novartis, Ono Pharmaceutical Co. Ltd., Otsuka Pharmaceutical Co., Ltd., Sanofi, Symbio, Takeda, Zenyaku; Board member for HUYA Japan, AstraZeneca, Abbvie, Eli Lilly, Genmab, Novartis; medical writing and article processing charges fees from Ono Pharmaceutical Co. Ltd. R.N. received research grants, medical writing and article processing charges fees from Ono Pharmaceutical Co. Ltd.; payment honoraria from Eisai Co., Ltd., Varian Medical Systems; consulting fees form Novocure. H.Y., K.A., K.S., and N.S. received research grants, medical writing, and article processing charges fees from Ono Pharmaceutical Co. Ltd. A.A. is an employee of Ono Pharmaceutical Co. Ltd., (© The Author(s) 2023. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.)