Ethics approval and consent to participate

The study protocol and all amendments were approved by the institutional review board or ethics committee at each participating institution. The study was conducted in accordance with the protocol, its amendments, the ethical principles originating from the Declaration of Helsinki, and Good Clinical Practice guidelines. Written informed consent was provided by all patients before enrollment.

Competing interests

RD reports grants or contracts from AstraZeneca and Roche; consulting fees from AstraZeneca, Daiichi Sankyo, Eisai, MSD, Novartis, Pfizer, and Roche; honoraria from AstraZeneca, Daiichi Sankyo, Eisai, MSD, Novartis, Pfizer, and Roche; support for attending meetings and/or travel from AstraZeneca, Daiichi Sankyo, Eisai, MSD, Novartis, and Roche; and participation on data safety monitoring boards or advisory boards for AstraZeneca, Daiichi Sankyo, Eisai, MSD, Novartis, and Roche. JC reports consulting fees from AbbVie, AstraZeneca, Bioasis, BioInvent, Boehringer Ingelheim, BridgeBio, Clovis Oncology, Daiichi Sankyo, Ellipses, Expres2ion Biotechnologies, GEMoaB, Gilead, Hibercell, Jazz Pharmaceuticals, Leuko, Lilly, Menarini, MSD, Reveal Genomics, Roche, Scorpion Therapeutics, Seattle Genetics, and Zymeworks; honoraria from AstraZeneca, Daiichi Sankyo, Eisai, Gilead, Lilly, MSD, Novartis, Pfizer, Roche, and Stemline Therapeutics; travel, accommodation, and expenses from AstraZeneca, Daiichi Sankyo, Eisai, Gilead, MSD, Novartis, Pfizer, Roche, and Stemline Therapeutics; patents (Pharmaceutical Combinations of a Pi3k Inhibitor and a Microtubule Destabilizing Agent. Javier Cortés Castán, Alejandro Piris Giménez, Violeta Serra Elizalde. WO 2014/199294 A. ISSUED and Her2 as a Predictor of Response to Dual HER2 Blockade in the Absence of Cytotoxic Therapy. Aleix Prat, Antonio Llombart, Javier Cortés.US 2019/0338368 A1. LICENSED); stock or stock options from MAJ3 Capital, Leuko (relative); and research funding to the institution from Ariad Pharmaceuticals, AstraZeneca, Baxalta GMBH/Servier Affaires, Bayer Healthcare, Eisai, F. Hoffman-LaRoche, Guardant Health, MSD, Pfizer, Piqur Therapeutics, IQVIA, Queen Mary University of London, and Roche. YHP reports grants or contracts from AstraZeneca, Gencurix, Genome Insight, MSD, Novartis, Pfizer, and Roche; consulting fees from AstraZeneca, Daiichi Sankyo, Eisai, EVEREST, Gilead, Lilly, MENARINI, MSD, Novartis, Pfizer, and Roche; honoraria from AstraZeneca, Daiichi Sankyo, Gilead, Lilly, MSD, Novartis, Pfizer, and Roche; support for attending meetings and/or travel from AstraZeneca, Gilead, and Pfizer; participation on a data safety monitoring board or advisory board for AstraZeneca, Daiichi Sankyo, MENARINI, Novartis, Pfizer, and Roche; and receipt of equipment, materials, drugs, medical writing, gifts, or other services from Dong-A ST, Pfizer, Roche, and Sanofi. EM-C reports consulting fees from BMS, MSD, Novartis, Pierra Fabre, and Sanofi; honoraria from BMS, MSD, Novartis, Pierre Fabre, and Sanofi; and support for attending meetings and/or travel from MSD and Novartis. S-BK reports consulting fees from Ansol Bioscience, AstraZeneca, BeiGene, Dae Haw Pharmaceutical Co. Ltd, Daiichi Sankyo, ISU Abxis, Lilly, Novartis, and OBI Pharma; and stock or stock options in Genopeaks. JS reports research funding to their institution from AstraZeneca, Boehringer Ingelheim, Daiichi Sankyo, GSK, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi, and Seagen and stock or stock options in Daiichi Sankyo. S-AI reports grants or contracts from AstraZeneca, Boryung Pharm, Daewoong Pharm, Daiichi Sankyo, Eisai, Pfizer, and Roche and consulting fees from AstraZeneca, Bertis, Daiichi Sankyo, Eisai, GSK, Hanmi, Idience, Lilly, MSD, Novartis, Pfizer, and Roche. EH has nothing to disclose. TF reports grants or contracts for clinical trial support from AstraZeneca, Novartis, Pfizer, and Veracyte; royalties for authorship of two chapters from UpToDate; consulting or private fees from Affibody, Exact Sciences, and Veracyte; honoraria for lectures to their institution from AstraZeneca, Daiichi Sankyo, Gilead, Pfizer, and Roche; and participation on an advisory board in December 2020 and private fees from Novartis. SK reports consulting fees from Lilly, MSD, Pink, and Somatex-Hologic; honoraria from Agendia, Amgen, AstraZeneca, Daiichi Sankyo, Exact Science, Gilead, Lilly, MSD, Novartis, Pfizer, Roche Pharma and Diagnostics, Seagen, Somatex-Hologic, and Sonoscape; support for attending meetings and/or travel from Daiichi Sankyo, Gilead, and Roche; participants on a data safety monitoring board or advisory board and payment from Agendia, Amgen, AstraZeneca, Daiichi Sankyo, Exact Science, Gilead, Lilly, Novartis, Pfizer, Roche Pharma and Diagnostics, MSD, Seagen, Somatex-Hologic, and Sonoscape; and a leadership or fiduciary role (no payment) for ESMO and WSG. JY reports employment at MSD, USA; stock or stock options in Merck & Co., Inc., Rahway, NJ, USA; patents issued and being filed, but not directly related to the manuscript; and receipt of equipment, materials, drugs, medical writing, gifts, or other services for work conducted as a full-time employee at MSD. AW reports employment at MSD and stock or stock options in Merck & Co., Inc., Rahway, NJ, USA. MN reports employment at MSD and stock or stock options in Merck & Co., Inc., Rahway, NJ, USA. LH reports employment at MSD and stock or stock options in Merck & Co., Inc., Rahway, NJ, USA. RC reports employment at MSD and stock or stock options in Merck & Co., Inc., Rahway, NJ, USA. PJ reports employment at MSD and stock or stock options in Merck & Co., Inc., Rahway, NJ, USA. VK reports employment at MSD; stock or stock options in Merck & Co., Inc., Rahway, NJ, USA; and support for attending meetings and/or travel from MSD. PS has nothing to disclose.