Background: The QUATTRO-II trial examined the efficacy and safety of capecitabine+oxaliplatin+irinotecan (CAPOXIRI)+bevacizumab (BEV) vs. 5-fluorouracil+folinic acid+oxaliplatin+irinotecan (FOLFOXIRI)+BEV in metastatic colorectal cancer (mCRC)., Methods: In this phase II study (ClinicalTrials.gov: NCT04097444; jRCTs041190072), patients were randomized (1:1) to FOLFOXIRI+BEV or CAPOXIRI+BEV. The induction treatment in the FOLFOXIRI+BEV/CAPOXIRI+BEV arms was continued for 8/6 cycles (maximum 12/8 cycles if feasible), and the maintenance treatment was 5-fluorouracil/leucovorin+BEV or capecitabine+BEV at the investigators' discretion. The primary endpoint was progression-free survival (PFS), with the two arms deemed equivalent if the hazard ratio (HR) of the point estimate was 0.80 < HR < 1.25. Secondary endpoints were overall response rate (ORR), overall survival (OS), incidence of adverse events (AEs), and patient-reported outcomes., Findings: Overall, 51 and 52 patients were randomized to FOLFOXIRI+BEV and CAPOXIRI+BEV, respectively. The study met its primary endpoint; PFS at median follow-up of 23.7 months was 10.6 months (95% confidence interval [CI], 7.7-13.3) in the FOLFOXIRI+BEV arm vs. 10.9 months (95% CI, 9.3-14.3) in the CAPOXIRI+BEV arm (HR 1.114 [0.80 < HR < 1.25], p = 0.654). In the FOLFOXIRI+BEV vs. CAPOXIRI+BEV arms, the 2-year OS rate (95% CI) was 65.5% (49.5%-77.6%) vs. 74.3% (59.8%-84.2%), and the ORR (95% CI) was 76.5% (62.5%-87.2%) vs. 84.6% (71.9%-93.1%). Major (grade ≥3) AEs in the FOLFOXIRI+BEV vs. CAPOXIRI+BEV arms were neutropenia (68.6% vs. 40.4%), febrile neutropenia (9.8% vs. 11.5%), diarrhea (7.8% vs. 17.3%), and appetite loss (7.8% vs. 17.3%)., Conclusion: CAPOXIRI+BEV was well tolerated with reduced hematological toxicity and efficacy comparable to those of FOLFOXIRI+BEV, providing a potentially convenient first-line treatment alternative to FOLFOXIRI+BEV in patients with mCRC., Funding: Chugai Pharmaceutical Co., Ltd., Competing Interests: Declaration of interests H.B. received grants from Ono Pharmaceutical. H.B. also reports honoraria for lectures from Ono Pharmaceutical, Eli Lilly Japan, and Taiho Pharmaceutical. D.K. reports honoraria from Takeda Pharmaceutical, Chugai Pharmaceutical, Novartis, Eli Lilly, Seagen, MSD, Ono Pharmaceutical, Eisai, Taiho Pharmaceutical, Bristol Myers Squibb, Daiichi-Sankyo, Pfizer, Merck Biopharma, and Sysmex and research funding from Ono Pharmaceutical, MSD, Novartis, Servier, Janssen, IQVIA, Syneoshealth, CIMIC, and Cimic Shift Zero. H.S. received grants from Ono Pharmaceutical, Daiichi Sankyo, Taiho Pharmaceutical, and Sanofi and reports honoraria from Bayer, Bristol-Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo, Eli Lilly Japan, Merck Bio Pharma, MSD, Ono Pharmaceutical, Sanofi, Taiho Pharmaceutical, Takeda Pharmaceutical, and Yakult Honsha. T.H. reports honoraria for lectures from Chugai Pharmaceutical. M.S. is on the speakers’ bureau at Johnson & Johnson, Kaken Pharmaceutical, Eli Lilly Japan, Merck Serono, Ono Pharmaceutical, Taiho Pharmaceutical, Takeda Pharmaceutical, and Yakult Honsha. M.K. reports honoraria for lectures from Chugai Pharmaceutical, Takeda Pharmaceutical, Eli Lilly, Yakult Honsha, and Taiho Pharmaceutical. T. Masuishi reports honoraria from Bayer Yakuhin, Bristol-Myers Squibb, Chugai Pharmaceutical, Daiichi Sankyo, Eli Lilly, Merck Serono, Ono Pharmaceutical, Sanofi, Taiho Pharmaceutical, Takeda Pharmaceutical, and Yakult Honsha and reports research funding from Amgen (Inst), Boehringer Ingelheim (Inst), CMIC (Inst), Daiichi Sankyo (Inst), Eli Lilly Japan (Inst), MSD (Inst), Novartis (Inst), Ono Pharmaceutical (Inst), Pfizer (Inst), and Syneos Health (Inst). H.Y. reports honoraria from Chugai Pharmaceutical and Yakult Honsha. Y. Kagawa reports honoraria from Chugai Pharmaceutical and Yakult Honsha. Y. Komatsu received grants from Ono Pharmaceutical, Chugai Pharmaceutical, Taiho Pharmaceutical, Shionogi, Nippon Zoki Pharmaceutical, Asahi Kasei Pharma Corporation, Nippon Kayaku, Daichi Sankyo, IQVIA Services Japan, MSD, Astellas Pharma, Incyte Corporation, Eisai, National Cancer Center Japan, Syneos Health Clinical, Shift Zero, PARAXEL International, Japan Clinical Cancer Research Organization, EPS Holdings, SYSMEX Corporation, Public Health Research Foundation, Aichi Cancer Center, and the Kyushu Study group of Clinical Cancer and reports honoraria for lectures from Ono Pharmaceutical, Taiho Pharmaceutical, Chugai Pharmaceutical, Daiichi Sankyo, Eli Lilly and Company, Alfresa Pharma Corporation, Astellas Pharma, EA Pharma, Nippon Kayaku, Pfizer, Nippon Zoki Pharmaceutical, Sanofi, NIPRO, MOROO, Boehringer lngelheim, Hakodate National Hospital, Asahi Kasei Pharma Corporation, MSD, Zeria Pharmaceutical, Bayer Yakuhin, Yakult Honsha, Sumitomo Dainippon Pharma, Incyte Corporation, Merck Biopharma, The Japanese Gastroenterological Association, Sapporo Minami Tokushukai Hospital, and Pancan Japan. E.O. is on the speakers’ bureau at Bristol-Myers Squibb Japan, Chugai Pharmaceutical, Eli Lilly Japan, Ono Pharmaceutical, Taiho Pharmaceutical, and Takeda Pharmaceutical and received research funding from Guardant Health. Y.Y. reports honoraria for lectures from Ono Pharmaceutical, Bristol Myers Squibb, Yakult, Chugai Pharmaceutical, Eli Lily, Bayer, Taiho Pharmaceutical, Servier, Takeda Pharmaceutical, Daiichi Sankyo, Teijin, and Insight. H.K. received grants or contracts from Chugai Pharmaceutical, Taiho Pharmaceutical, and Eisai and received consulting fees from BMS, Eli Lilly Japan, Ono Pharmaceutical, Daiichi Sankyo, and Taiho Pharmaceutical; and has received honoraria from BMS, Bayer Yakuhin, Eli Lilly Japan, MSD, Ono Pharmaceutical, Chugai Pharmaceutical, Daiichi Sankyo, Takeda Pharmaceutical, and Taiho Pharmaceutical. T. Misumi reports honoraria from Chugai Pharmaceutical, AstraZeneca, and Miyarisan. H.T. received lecture fees from Takeda Pharmaceutical, Ono Pharmaceutical, Eli Lilly, Merck Biopharma, and Chugai Pharmaceutical and received research funds from Takeda Pharmaceutical, Daiichi Sankyo, and Ono Pharmaceutical. K.Y. reports honoraria for lectures from Chugai Pharmaceutical, Yakult, Daiichi Sankyo, Merk Serono, Sanofi, MSD, Takeda Pharmaceutical, Taiho Pharmaceutical, Bayer, Eli Lily, Ono Pharmaceutical, and Bristol-Myers Squibb. K.M. reports honoraria from Bristol-Myers Squibb, Daiichi Sankyo, MSD, Eli Lilly, Ono Pharmaceutical, Taiho Pharmaceutical, and Takeda Pharmaceutical; reports a consulting or advisory role at Amgen, Astellas Pharma, AstraZeneca, Chugai Pharmaceutical, and Ono Pharmaceutical; and received research funding from Amgen (Inst), Astellas Pharma (Inst), Chugai Pharmaceutical (Inst), Eisai (Inst), MSD (Inst), Novartis (Inst), Ono Pharmaceutical (Inst), Sanofi (Inst), and Taiho Pharmaceutical (Inst). T.Y. received consulting fees Sumitomo Corporation; received grants from Amgen, Chugai Pharmaceutical, Daiichi Sankyo, Eisai, FALCO biosystems, Genomedia, Molecular Health GmbH, MSD, Nippon Boehringer Ingelheim, Ono Pharmaceutical, Pfizer Japan, Roche Diagnostics, Sanofi, Sysmex, and Taiho Pharmaceutical; and reports honoraria for presentations from Bayer Yakuhin, Chugai Pharmaceutical, Merck Biopharma, MSD, Ono Pharmaceutical, and Takeda Pharmaceutical. T.K. reports honoraria for lectures from Chugai Pharmaceutical, Ono Pharmaceutical, Taiho Pharmaceutical, Takeda Pharmaceutical, and Eli Lilly and Company. A.T. is on the speakers' bureau at Bristol-Myers Squibb, Chugai Pharmaceutical, Eli Lilly Japan, Merck Serono, Sanofi, Taiho Pharmaceutical, and Takeda Pharmaceutical and reports research funding from Ono Pharmaceutical (Inst), Sanofi (Inst), and Taiho Pharmaceutical (Inst)., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)