Bevacizumab Approved for Recurrent Glioblastoma Brain Cancer
The FDA has granted accelerated approval of bevacizumab (Avastin) for patients with previously treated glioblastoma multiforme (GBM), a deadly form of brain cancer. Accelerated approval is granted to treatments for life-threatening diseases on the basis of preliminary evidence, with the requirement that additional studies be conducted to confirm a true clinical benefit. Bevacizumab is a monoclonal antibody that inhibits the formation of new blood vessels that tumors need for continued growth.
The approval was based on results from two early phase clinical trials in which a modest portion of patients had partial responses, but no patients had complete responses. The first trial included 85 patients, with approximately 25 percent experiencing a partial response (tumor shrinkage of greater than 50 percent). In the other trial, conducted at NCI, of 56 patients treated with bevacizumab, 20 percent had a partial response. One-year overall survival in the first trial was 38 percent, compared with approximately 25 percent historically seen in patients who had recurrent GBM and received salvage chemotherapy.
In March, the FDA’s Oncologic Drugs Advisory Committee voted unanimously in favor of granting accelerated approval of bevacizumab for this indication. A global, randomized phase III trial of bevacizumab in patients with newly diagnosed GBM will start enrolling patients some time in 2009.