Chimeric antigen receptor (CAR) T-cell therapy has shown promise in patients with late-line refractory multiple myeloma, with response rates ranging from 73 to 98%. To date, three products have been approved: Idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel), which are approved by the US Food and Drug Administration, the European Medicines Agency, Health Canada (ide-cel only), and Brazil ANVISA (cilta-cel only); and equecabtagene autoleucel (eque-cel), which was approved by the Chinese National Medical Products Administration. CAR T-cell therapy is different from previous anti-myeloma therapeutics with unique toxic effects that require distinct mitigation strategies. Thus, a panel of experts from the International Myeloma Working Group was assembled to provide guidance for clinical use of CAR T-cell therapy in myeloma. This consensus opinion is from experts in the field of haematopoietic cell transplantation, cell therapy, and multiple myeloma therapeutics., Competing Interests: Declaration of interests YL received consultancy fees from Janssen, Sanofi, NexImmune, Caribou, Bristol Myers Squibb (BMS), Pfizer, Regeneron, and Genentech; research fees from Janssen and BMS; serves on advisory boards for Janssen, Sanofi, BMS, Regeneron, and Genentech; serves on scientific advisory boards for NexImmune and Caribou; and serves on the data safety monitor board for Pfizer. LQ received consultancy fees from Beigene, Xi'an, Janssen, Pfizer, Sanofi, and AstraZeneca; and is on the speaker board for Beigene, Xi'an, Janssen, Pfizer, Sanofi, AstraZeneca, and Roche. SU receives consultancy fees from AbbVie, Amgen, BMS, EdoPharma, Genentech, Gilead, GlaxoSmithKline (GSK), Janssen, Karyopharm Therapeutics, Merck, Oncopeptides, Sanofi, Seagen, Secura Bio, SkylineDx, and Takeda; and received research funding from AbbVie, Amgen, Array Biopharma, BMS, EdoPharma, Genentech, Gilead, GSK, Janssen, Merck, Moderna, Pharmacyclics, Seagen, Sanofi, SkylineDx, Takeda, and TeneoBio. CWJ received honoraria from AbbVie, Amgen, BMS, Pfizer, Sanofi, Regeneron, GSK, and Janssen; and research funding from Novartis, Janssen, and BMS Celgene. LC received research grants from Amgen, Janssen, BMS, Genentech, Caribou, and AbbVie; and honoraria from Amgen, Janssen, AbbVie, Pfizer, Sanofi, and Adaptive Biotechnologies. BD received advisory board and consulting fees from Janssen and COTA; research fees from GSK and Amgen; honoraria from the Multiple Myeloma Research Foundation and Plexus Communications; and is an independent reviewer for BMS. HE has an advisory role for and received consulting fees from BMS Celgene, Janssen, Amgen, GSK, and Sanofi; and received research funding from BMS Celgene, Janssen, Amgen, GSK, and Sanofi. CFdL received institutional grants from BMS, Janssen, and Amgen; honoraria from Amgen, Jassen, BMS, GSK, and Sanofi; support for attending meetings or travel from Janssen, BMS, GSK, and Amgen; is on data safety monitoring or advisory boards for Janssen, BMS, Amgen, Pfizer, and Sanofi; and received funding from the Spanish Institute of Health, the Asociación Española Contra el Cancer (AECC), the “La Caixa” Foundation, and AGAUR. RH received grants from Janssen, Amgen, Celgene, BMS, Novartis, and Takeda; consulting fees from Janssen, Amgen, Celgene, BMS, Novartis, Takeda, AbbVie, PharmaMar, Oncopeptides, Sanofi, and GSK; and honoraria from Janssen, Amgen, Celgene, BMS, PharmaMar, and Takeda. PJH serves on advisory boards (honoraria not accepted) for Antengene, Gilead, iTeos Therapeutics, Janssen, Novartis, and Pfizer. EK received honoraria from Janssen, Pfizer, GSK, and Prothena; and research support to the institution from GSK, Janssen, and Pfizer. JM-L received consultancy fees from Janssen, BMS, Sanofi, GSK, Novartis, Menarini, Incity, Roche, Gilead, Pfizer, and Karyopharm; and research funding from BMS, Janssen, Incity, Amgen, and Pfizer. M-VM received honoraria for serving on advisory boards and received fees for lectures from Janssen, BMS Celgene, Novartis, GSK, Sanofi, Amgen, Pfizer, AbbVie, and Regeneron. JM received consultancy fees from Amgen, BMS, Janssen, Sanofi, and Takeda; and research funding from BMS Clinical Trial. PM serves on advisory boards and received honoraria from Janssen and BMS Celgene. CN received consultancy fees from Janssen, BMS, Sanofi, GSK, Pfizer, Amgen, AstraZeneca, and DKSH; and research funding from Janssen and Amgen. AN serves on advisory boards and received honoraria from Adaptive Biotechnologies, Amgen, BMS, Cellectar Biosciences, GSK, Janssen, K36 therapeutics, ONK therapeutics, Pfizer, Sanofi, and Takeda; received research grants from Aduro Biotech, Amgen, Arch Oncology, BMS, Cellectis, Genentech, GSK, Janssen, Karyopharm, Kite Pharma, Merck, Pfizer, and Takeda; and received grants for investigator initiated studies from Amgen, GSK, Janssen, Merck, and Takeda. FS received consultancy fees from AbbVie, GSK, Celgene, Takeda, Janssen, Oncopeptides, Sanofi, and BMS; honoraria from Amgen, BMS, Takeda, AbbVie, Janssen, Novartis, SkyliteDX, Oncopeptides, Sanofi, Pfizer, Daiki-Sankyo, and GSK; and research grants from Celgene, Janssen, Oncopeptides, Sanofi, GSK, and Targovax. SS received research grants from Magenta Therapeutics, BMS, Allogene, Jansse, Novartis, AbbVie, Sanofi, Oncopeptides, Takeda, Kite, and Regeneron; and consultancy fees from Magenta Therapeutics, BMS, Janssen, AbbVie, Sanofi, Oncopeptides, Takeda, Kite, and Regeneron. NWCJvdD received research grants from Janssen, Amgen, Celgene, Novartis, Cellectis, and BMS; and serves on advisory boards for Janssen, Amgen, Celgene, BMS, Sanofi, Takeda, Roche, Novartis, Bayer, Adaptive, Pfizer, AbbVie, and Servier (all paid to institution). KW received research grants from AbbVie, Amgen, BMS Celgene, Janssen, GSK, Sanofi, and Takeda; honoraria from AbbVie, Amgen, Adaptive Biotech, Astra Zeneca, BMS Celgene, BeiGene, Janssen, GSK, Karyopharm, Novartis, Oncopeptides, Pfizer, Roche Pharma, Sanofi, Stemline, Takeda, and Menarini; and consulting fees from AbbVie, Amgen, Adaptive Biotech, BMS Celgene, BeiGene, Janssen, GSK, Karyopharm, Oncopeptides, Pfizer, Roche Pharma, Sanofi, Takeda, and Menarini. SZ serves on advisory boards for Janssen, BMS, Takeda, Sanofi, Oncopeptides, and Amgen (no personal fees). PRO received honoraria for consulting or advisory board from BMS Celgene, Janssen, Roche, AbbVie, Pfizer, GSK, Sanofi, H3Biomedicine; travel grants from Pfizer; serves on steering committees for BMS Celgene, Regeneron, and Janssen; and is on the speakers bureau for Janssen, BMS Celgene, GSK, Sanofi, and AbbVie. LDA received consulting fees and serves on advisory boards for Janssen, Celgene, BMS, Amgen, GSK, AbbVie, Beigene, Cellectar, Sanofi, and Prothena. SK received consultancy fees from Oncopeptides, AbbVie, Celgene, Janssen, Takeda, Adaptive, KITE, and MedImmune AstraZeneca; and research grants from AbbVie, Celgene, Janssen, Takeda, Adaptive, KITE, MedImmune AstraZeneca, Merck, Novartis, Roche, and Sanofi. TM received research funding from Sanofi. All other authors declare no competing interests. IMWG are listed in the appendix (pp 9–21)., (Copyright © 2024 Elsevier Ltd. 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