Feasibility of biweekly combination chemotherapy with capecitabine, irinotecan, and oxaliplatin in patients with metastatic solid tumors: results of a two-step phase I trial: XELIRI and XELIRINOX

Background Biweekly schedule of capecitabine combined with irinotecan (XELIRI), consecutively with irinotecan and oxaliplatin (XELIRINOX), was evaluated in patients with metastatic cancer from any solid tumors. Patients and methods In this two-step phase I trial, seventeen and eleven patients were enrolled in the XELIRI and XELIRINOX stages, respectively. Results In XELIRI, a total of 136 chemotherapy cycles were administered with a median number of 8 cycles per patient (2–16). Main dose-limiting toxicities (DLT) were grade 3–4 neutropenia, with one toxicity-related death. Maximum tolerated dose (MTD) for capecitabine combined with 180 mg/m 2 of irinotecan was 3,500 mg/m 2 /day. In XELIRINOX, capecitabine starting dose was 2,500 mg/m 2 /day. Fifty-eight chemotherapy cycles were administered with a median of 4 cycles per patient (1–16). DLT included 3 grade 4 neutropenia, associated with 1 grade 3 diarrhea, and 1 grade 4 pneumopathy leading to patient death. MTD for capecitabine with 180 mg/m 2 of irinotecan and 85 mg/m 2 of oxaliplatin was 3,000 mg/m 2 /day. The recommended doses for capecitabine were 3,000 and 2,500 mg/m 2 /day D1–D7 in combination with 180 mg/m 2 of irinotecan in XELIRI, plus 85 mg/m 2 of oxaliplatin in XELIRINOX (D1 = D14), respectively. Conclusion XELIRI and XELIRINOX regimens are feasible and warrant further investigation in combination with targeted therapy in metastatic colorectal cancer patients.