Phase II study of capecitabine plus oxaliplatin (XELOX) as first-line treatment and followed by maintenance of capecitabine in patients with metastatic colorectal cancer

The aim of this study is to evaluate the safety and efficacy of the combination of capecitabine and oxaliplatin (XELOX) as first-line treatment in Chinese patients with metastatic colorectal carcinoma (mCRC). Furthermore, we aimed to explore whether a maintenance therapy with oral capecitabine in patients who were non-progression to the XELOX regimen was able to improve the duration of disease control (DDC). One hundred twenty-four patients with mCRC received a 3-weekly regimen of oxaliplatin plus capecitabine (XELOX) as first-line treatment. Patients without progressive disease after six cycles of XELOX could stop treatment or continue to receive oral capecitabine until disease progression or unacceptable toxicity. A total of 637 cycles (median 6 cycles) of XELOX were given to 124 patients (males 58.1%, median age 52 years). The response rate was 49.1% (complete response in 11 patients and partial response in 50 patients). The median overall survival and progression-free survival were 20.0 and 8.0 months, respectively. Main drug-related grade 3–4 toxicities included neutrapenia (5.6%), nausea/vomiting (4%), thrombocytopenia (2.4%), diarrhea (2.4%) and hand–foot syndrome (2.4%). Among 62 patients achieving objective response or stable disease after at least 6 cycles of XELOX, there were 22 patients received oral capecitabine as maintenance therapy. The median DDC was significantly longer for maintenance therapy group than those of no maintenance group (14 vs. 9 months; P = 0.041). XELOX is a highly effective first-line treatment for Chinese mCRC patients. The response rate, TTP, and overall survival of patients treated with this regimen are similar to those treated with FU/leucovorin/oxaliplatin. Furthermore, our preliminary data show maintenance therapy with capecitabine for those patients without progressive disease after at least six cycles of XELOX can significantly improve DDC; and further prospective randomized control trial is warranted.