Background: Capecitabine and irinotecan combination therapy(XELIRI) has been examined at various dose levels to treat metastatic colorectal cancer(m CRC). Recently, in the Association of Medical Oncology of the German Cancer Society(AIO) 0604 trial, tri?weekly XELIRI plus bevacizumab, with reduced doses of irinotecan(200 mg/m~2 on day 1) and capecitabine(1600 mg/m~2 on days 1–14), repeated every 3 weeks, has shown favorable tolerability and eicacy which were comparable to those of capecitabine and oxaliplatin(XELOX) plus bevacizumab. The doses of capecit?abine and irinotecan in the AIO trial are considered optimal. In a phase I/II study, XELIRI plus bevacizumab(BIX) as second?line chemotherapy was well tolerated and had promising eicacy in Japanese patients.Methods: The Asian XELIRI Projec T(AXEPT) is an East Asian collaborative, open?labelled, randomized, phase Ⅲ clinical trial which was designed to demonstrate the non?inferiority of XELIRI with or without bevacizumab versus standard FOLFIRI(5?fluorouracil, leucovorin, and irinotecan combination) with or without bevacizumab as second?line chemo?therapy for patients with m CRC. Patients with 20 years of age or older, histologically conirmed m CRC, Eastern Coop?erative Oncology Group performance status 0–2, adequate organ function, and disease progression or intolerance of the irst?line regimen will be eligible. Patients will be randomized(1:1) to receive standard FOLFIRI with or with?out bevacizumab(5 mg/kg on day 1), repeated every 2 weeks(FOLIRI arm) or XELIRI with or without bevacizumab(7.5 mg/kg on day 1), repeated every 3 weeks(XELIRI arm). A total of 464 events were estimated as necessary to show non?inferiority with a power of 80% at a one?sided α of 0.025, requiring a target sample size of 600 patients. The 95% conidence interval(CI) upper limit of the hazard ratio was pre?speciied as less than 1.3.Conclusion: The Asian XELIRI Projec T is a multinational phase III trial being conducted to provide evidence for XELIRI with or without bevacizumab as a second?line treatment option of mCRC. Background: Capecitabine and irinotecan combination therapy (XELIRI) has been examined at various dose levels to treat metastatic colorectal cancer (m CRC). Recently, in the Association of Medical Oncology of the German Cancer Society (AIO) 0604 trial, tri? Weekly XELIRI plus bevacizumab, with reduced doses of irinotecan (200 mg / m 2 on day 1) and capecitabine (1600 mg / m 2 on days 1-14), repeated every 3 weeks, has shown favorable tolerability and eicacy which were comparable to those of capecitabine and oxaliplatin (XELOX) plus bevacizumab. The doses of capecit® abine and irinotecan in the AIO trial are considered optimal. In a phase I / II study, XELIRI plus bevacizumab (BIX) as second? line chemotherapy was well tolerated and had promising eicacy in Japanese patients. Methods: The Asian XELIRI Projec T (AXEPT) is an East Asian collaborative, open? labelled, randomized, phase III clinical trial which was designed to demonstrate the non? inferiority of XELIRI with or without bevacizumab versus stand ard FOLFIRI (5? fluorouracil, leucovorin, and irinotecan combination) with or without bevacizumab as second? line chemo? therapy for patients with m CRC. Patients with 20 years of age or older, histologically conirmed m CRC, Eastern Coop erative Oncology Group Performance status 0-2, adequate organ function, and disease progression or intolerance of the irst? line will be randomized (1: 1) to receive standard FOLFIRI with or with? out bevacizumab (5 mg / kg on day 1), repeated every 2 weeks (FOLIRI arm) or XELIRI with or without bevacizumab (7.5 mg / kg on day 1), repeated every 3 weeks (XELIRI arm). A total of 464 events were estimated as necessary to show non? The 95% conidence interval (CI) upper limit of the hazard ratio was pre? speciied as less than 1.3. Conlusion: The inferiority with a power of 80% at a one- sided α of 0.025, requiring a target sample size of 600 patients. The Asian XELIRI Projec T is a multinational phase III trial being conducted to provide evid ence for XELIRI with or without bevacizumab as a second? line treatment option of mCRC.