Capecitabine plus oxaliplatin (XELOX) followed by capecitabine plus irinotecan (XELIRI) in a sequential schedule in first-line metastatic colorectal cancer (MCRC): a phase II multicenter study
13516 Background: In phase II trials, XELOX and XELIRI were highly active and well tolerated in first-line MCRC. The aim of this study is to explore the efficacy and safety of XELOX followed by XELIRI as first-line treatment in MCRC. Specifically, we wanted to evaluate the impact of sequential scheduling on the dose-limiting neurotoxicity associated with oxaliplatin accumulation. Methods: Eligible patients (pts) had histologically or cytologically confirmed MCRC, ECOG PS ≤ 2 and adequate bone marrow, renal and hepatic function. Prior chemotherapy for MCRC was not allowed. Pts received 4 cycles of XELOX (capecitabine 1000mg/m2 orally bid d1–14 + oxaliplatin 130mg/m2 i.v. d1, q3w) followed by 4 cycles of XELIRI (capecitabine 1000mg/m2 bid d1–14 + irinotecan 240mg/m2 i.v. d1, q3w). This sequential schedule was repeated until unacceptable toxicity or disease progression. Results: Of the 35 pts analized to date: M/F (69%/31%); median age 68 years (range 41–78); ECOG PS 0–1 (94%); surgery (77%) and adjuvant chemotherapy (31%). 240 cycles (median 6, range 1–16) have been administered. 35 pts received XELOX (123 cycles, median 4), and 21 pts received XELIRI (83 cycles, median 4) in the first sequential schedule. In the second sequential schedule 6 pts received XELOX (22 cycles, median 4) and 4 pts received XELIRI (12 cycles, median 3.5). Median relative dose intensity was 88% for XEL, 96% for OX and 92% for IRI. In 27 efficacy evaluable pts, the ORR was 48% (95% CI, 29–67%). Eight pts were not evaluable due to adverse events (n=6), ongoing treatment (n=1) and lost of follow up (n=1). Conclusions: This sequential schedule is active and well tolerated in first-line MCRC. The improvement/recovery of the oxaliplatin-related neurotoxicity during the XELIRI phase is also promising and allows the re-treatment with oxapliplatin in the next sequence without accumulating neurotoxicity. Final results will be presented at the meeting. [Table: see text] No significant financial relationships to disclose.