Antiangiogenesis Research Is Booming, As Questions and Studies Proliferate

Extract

In a recent analysis of a large observational study, bevacizumab (Avastin), an inhibitor of angiogenesis, was associated with favorable survival rates in patients whose colorectal cancer had already progressed. Those taking bevacizumab with chemotherapy had a median overall survival of 32 months, compared with 20 months for those who did not receive bevacizumab beyond first-line therapy. The difference was statistically significant.

The analysis, published in November, was based on data from a patient registry known as BRiTE, which is designed primarily to gather information on adverse events and secondarily on progression-free and overall survival. Nevertheless, the positive results buoyed researchers.

“We did not expect patients to receive such a magnitude of benefit,” said lead investigator Axel Grothey, M.D. , a professor at the Mayo Clinic in Rochester, Minn. The researchers concluded that bevacizumab beyond initial disease progression might benefit patients who have metastatic colorectal cancer.

But compare the BRiTE results to those of a prospective controlled trial—considered a stronger study design—in patients with metastatic colorectal cancer, also published last year. In this multicenter, phase III trial, patients were randomized to either first-line treatment with bevacizumab and chemotherapy until disease progression or chemotherapy alone. Patients taking the combination had a disappointing median overall survival of 21.3 months compared with those taking only chemotherapy, who lived a median 19.9 months. The difference was not statistically significant.