Evaluating the safety and efficacy of adding bevacizumab in two capecitabine-based chemotherapy regimens for the treatment of patients with metastatic colorectal cancer

This phase II clinical trial investigated the addition of bevacizumab to two chemotherapy regimens for the first line treatment of patients with metastatic colorectal cancer (CRC).

Cancer cells need blood supply in order to grow. They do so by forming new blood vessels, thus feeding themselves. Bevacizumab (Avastin) is type of biological therapy (a treatment that stimulates the body’s immune system to fight cancer) approved for the treatment of some types of metastatic cancer, including CRC. Bevacizumab inhibits the growth of new blood vessels of the cancer, thus slowing the progression of cancer. The standard treatment for CRC that has spread to other organs or tissues in the body (metastatic CRC) is chemotherapy, but biological therapies such as bevacizumab could be added. Bevacizumab has been shown to increase the length of time patients survive without any disease progression (progression free survival or PFS) when it is used in combination with chemotherapy drugs such as irinotecan (Camptosar) or oxaliplatin (Eloxatin). Capecitabine (Xeloda) is another chemotherapy drug that has shown good results when used alone for patients with metastatic CRC. This research aimed to evaluate the safety and efficacy of adding bevacizumab in different capecitabine-based chemotherapy drug combinations for the treatment of patients with metastatic CRC.

In total, this study included 247 patients with metastatic CRC. 127 participants were treated with bevacizumab in combination with capecitabine and oxaliplatin (CapOx-bevacizumab) and 120 patients received bevacizumab in combination with capecitabine and irinotecan (CapIri-bevacizumab). Patients were followed for approximately 2 years.

After the first 6 months of follow up, 76% of patients in the CapOx-bevacizumab treatment group and 84% of patients in the CapIri-bevacizumab group remained progression free (had stable disease). The average PFS time for patients treated with CapOx-bevacizumab was 10.4 months, compared to 12.1 months for patients treated with CapIri-bevacizumab. The overall survival (the time patients survived after treatment with or without the disease) was 24.4 months in patients treated with CapOx-bevacizumab and 25.5 months in patients who received CapIri-bevacizumab. The most common side effect reported was diarrhea, which was more frequently found in patients treated with CapOx-bevacizumab (22%) than in patients treated with CapIri-bevacizumab (16%).

In summary, both treatment regimes evaluated in this study showed good progression free survival rates. In addition, the regimens appeared to be well tolerated, with manageable side effects. These results indicate that bevacizumab can be safely added to first line chemotherapy treatment of patients with metastatic CRC when using the regimens described within this study.

This study was funded by Roche Pharma AG, the manufacturer of Avastin and Xeloda, and by Sano?-Aventis, the manufacturer of Eloxatin.