Declaration of interests JSW has been a consultant for AstraZeneca, Bristol Myers Squibb, Merck, and Regeneron; has received research grants (to institution) from Merck and Moderna; has received travel support from Moderna; and is named on a PD-1 patent with Biodesix (not related to this trial). MSC has been a consultant for Amgen, Bristol Myers Squibb, Eisai, Ideaya, Merck Sharp & Dohme, Nektar, Novartis, Oncosec, Pierre-Fabre, Qbiotics, Regeneron, Roche, Merck Serono, and Sanofi; and has received honoraria from Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, and Sanofi. AK has received honoraria from Merck Sharp & Dohme. TaM has received research grants (to institution) from Moderna; has been a consultant or served on a data safety monitoring–advisory board for AstraZeneca, Bristol Myers Squibb, Eisai, GlaxoSmithKline, Merck Sharp & Dohme, and Novartis; has received payment or honoraria from AstraZeneca; and has received travel support from AstraZeneca and Bristol Myers Squibb. MHT has received research grants from Bristol Myers Squibb, Exelixis, and Merck; has been a consultant for Cascade Prodrug, Incyte, and Immune-Onc; has received payment or honoraria from Array Biopharma, Bayer, Blueprint Medicines, Bristol Myers Squibb, Eisai, Merck, Novartis, and Sanofi/Regeneron; and has served on a data safety monitoring or advisory board for Oncosec. KBK has received research grants from Merck and Moderna. MMc has received research grants (to institution) from Aadi Biosciences, Alpine Immune Sciences, Arcus Biosciences, Arvinas, Ascentage Pharma Group, ASCO, Astellas, Bayer, Bicycle Therapeutics, BioMed Valley Discoveries, BioNTech, C4 Therapeutics, Dragonfly Therapeutics, EMD Serono, Epizyme, Erasca, Exelixis, Foghorn Therapeutics, G1 Therapeutics, Genentech–Roche, Gilead Sciences, GlaxoSmithKline, IDEAYA Biosciences, Ikena Oncology, ImmVira Pharma, Infinity Pharmaceuticals, Jacobio Pharmaceuticals, Kechow Pharma, Kezar Life Sciences, Kinnate BioPharma, MedImmune, Merck, Mereo BioPharma, Metabomed, Moderna, NBE Therapeutics, Nektar, Novartis, OncoC4, Oncorus, PACT Pharma, Pfizer, Plexxikon, Poseida, Prelude Therapeutics, Pyramid Biosciences, Regeneron, Sapience Therapeutics, Scholar Rock, Seattle Genetics, Synthrox, Takeda Pharmaceuticals, Teneobio, Tempest Therapeutics, Tizona Therapeutics, TMUNITY Therapeutics, TopAlliance Biosciences, and Xilio; and has been a consultant (payment to institution) for Castle Biosciences, Eisai, IQVIA, Merck, Moderna, and Pfizer. GVL has been a consultant for Agenus, Array Biopharma, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Evaxion, Hexal (Sandoz Company), Highlight Therapeutics, Innovent Biologics USA, Merck Sharp & Dohme, Novartis, OncoSec, PHMR, Pierre Fabre, Provectus, Qbiotics, and Regeneron; has received honoraria from Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, and Pierre Fabre; and has served on an advisory board for Bristol Myers Squibb, Merck Sharpe & Dohme, Novartis, OncoSec, Pierre Fabre, Provectus, Qbiotics, and Regeneron. RJS has received research grants from Merck; has royalties or licences from Up-to-Date; has been a consultant for Marengo, Merck, Novartis, Pfizer, and Replimune; and has served on a data safety monitoring or advisory board for Duke University and Yale University. MF has received research grants from Moderna; and has served on an advisory board for Bristol Myers Squibb, Instil Bio, Merck, Novartis, and Regeneron. CLC has been a consultant for and has served on an advisory board for EMD Serono, Eisai, Iovance, Merck, Regeneron, and Replimune. AP has had a leadership position in Cota Healthcare and OMI; and holds stock options in Celularity and OMI. ThM has received research grants from Agenus, Anaveon, Bioatla, Bristol Myers Squibb, Day One, Genentech, InflaRx, Iovance, Merck, Regeneron, Replimune, Trisalus, and Ultimovacs; has received payment or honoraria from Honor Health; and has served on a data safety monitoring or advisory board for University of Colorado Cancer Center. VA has received speaker fees from Bristol Myers Squibb, Merck Sharp & Dohme, Novartis, and Pierre Fabre; has received travel support from Bristol Myers Squibb and Pierre Fabre; and has served on an advisory board for Bristol Myers Squibb, Immunocore, Limbic, Merck Sharp & Dohme, Novartis, and QBiotics. GTG has received research grants (to institution) from Exelixis and Lucerno Dynamics; has been a consultant for Bristol Myers Squibb, Eisai, Exicure, Genentech, Immunocore, Incyte, Iovance, Lyell Immunopharma, Merck, Novartis, Regeneron, and Sapience Therapeutics; has received payment or honoraria from Immunocore; and has served on a data safety monitoring or advisory board for Huyabio. JJL has received research support (all to institution for clinical trials) from AbbVie, Astellas, AstraZeneca, Bristol Myers Squibb, Corvus, Day One, EMD Serono, Fstar, Genmab, Ikena, Immatics, Incyte, Kadmon, KAHR, Macrogenics, Merck Sharp & Dohme, Moderna, Nektar, Next Cure, Numab, Palleon, Pfizer, Replimmune, Rubius, Servier, Scholar Rock, Synlogic, Takeda, Trishula, Tizona, and Xencor; has been a consultant for 7 Hills, AbbVie, Actym, Alnylam, Alphamab Oncology, Arch Oncology, Atomwise, Bayer, Bright Peak, Bristol Myers Squibb, Castle, Checkmate, Codiak, Crown, Cugene, Curadev, Day One, Duke Street Bio, Eisai, EMD Serono, Endeavor, Exo, Flame, Fstar, G1 Therapeutics, Genentech, Gilead, Glenmark, HotSpot, Kadmon, Kanaph, KSQ, Janssen, Ikena, Inzen, Immatics, Immunocore, Incyte, Instil, Inzen, IO Biotech, Macrogenics, Mavu, Merck Sharp & Dohme, Mersana, Nektar, NeoTx, Novartis, Onc.AI, OncoNano, Partner, Pfizer, Pioneering Medicines, PsiOxus, Pyxis, RefleXion, Regeneron, Ribon, Roivant, Saros, Servier, STINGthera, Stipe, Synlogic, Synthekine, Tempest, and Xilio; has served on an advisory board for AbbVie, Evaxion, and Immutep; is a board member of the Society for Immunotherapy of Cancer; holds stock options in Actym, Alphamab Oncology, Arch Oncology, Duke Street Bio, Kanaph, Mavu, NeoTx, Onc.AI, OncoNano, Pyxis, Saros, STipe, and Tempest; and has applied for patents (both provisional) for Serial 15/612,657 (Cancer Immunotherapy) and PCT/US18/36052 (Microbiome Biomarkers for Anti-PD-1/PD-L1 Responsiveness: diagnostic, prognostic and therapeutic uses thereof). ST has received speaker fees from Bristol Myers Squibb and honoraria from Pfizer; and has served as a paid expert witness for malpractice cases. EIB has received research grants (to institution) from Genentech; has been a consultant for Instilbio, Iovance, Merck, Nektar, Novartis, Sanofi, and Xilio; and has served on a data safety monitoring–advisory board for Asher. JAH is an employee of and holds stock options in Merck & Co, Rahway, NJ, USA. MH is an employee of Merck &Co, Rahway, NJ, USA. MaM, LZ, CR-T, PH, and PA are employees of and hold stock options in Moderna. IF is an employee of and holds stock options in Moderna; and was a co-inventor on the individualised neoantigen therapy Moderna patent. VS is an employee of Moderna; and holds stock options in AbbVie and Moderna. MB is an employee of Moderna; and holds stock options in Bristol Myers Squibb, Moderna, and Novartis. RSM is an employee of and holds stock and options in Moderna; and was a co-inventor on the individualised neoantigen therapy patent and other seminal Moderna patents. TZ is an employee of and holds stock options in Moderna; was a co-inventor on some seminal Moderna patents; and has served as a paid board member for Adaptimmune and Teva Pharmaceuticals. GA, TTT, MS, and JS declare no competing interests.