The FDA recently approved Avastin (bevacizumab), manufactured by Genentech, to treat glioblastoma multiforme (GBM), a type of brain cancer, that hasn't responded to other therapies. The approval is the latest for the drug, which is also used to treat certain types of breast, lung, colon, and rectum cancers.

Glioblastomas are fast-growing brain tumors that can invade normal brain tissue, which can make them very difficult to treat. After initial treatment with surgery, radiation, and/or chemotherapy, they often come back. Genentech is calling the drug the "first new treatment for glioblastoma in more than a decade," according to a press release.

"This type of cancer is very resistant to therapy and thus challenging to treat," said Richard Pazdur, MD, director of the Office of Oncology Drug Products in the FDA’s Center for Drug Evaluation and Research. "Avastin provides a therapy for patients with progressive GBM who have not responded to other medications."

The FDA approved Avastin for GBM under its accelerated approval process, which aims to make drugs for life-threatening diseases available more quickly.

The approval was based on the results of 2 phase II clinical trials that showed Avastin reduced tumor size in some glioblastoma patients. The first study split 167 patients into 2 groups: one group received Avastin alone; the other a combination of Avastin and the chemotherapy drug irinotecan. Of the 85 patients treated with Avastin alone, 26% had their tumors shrink in response to the drug. In the second trial, which followed 56 patients who were treated with Avastin alone, 20% responded to the drug. In both studies, the effect lasted for an average of about 4 months.

The studies were not able to determine if the drug relieved symptoms of the disease or if it helped people live longer. Some serious side effects included bleeding/hemorrhage, high blood pressure, nose bleeds, blood clots in veins or arteries, holes (perforations) in the stomach or intestines, and wound-healing complications. More common but less serious side effects included headache, irritated nose, protein in the urine, taste alteration, dry skin, rectal bleeding, tear production disorder, and inflammation of the skin.

"Today's approval would not have been possible without the dedication of physicians, patient advocates, the FDA and most importantly the people who participated in the clinical trials and their families who had the courage to support them," said Hal Barron, MD, executive vice president, global development and chief medical officer, Genentech, when the FDA announcement was made. "A global Phase III trial in patients with newly diagnosed glioblastoma will soon begin enrollment to further evaluate Avastin in this setting." Other studies of Avastin to treat brain tumors are ongoing as well.

Avastin works by slowing the growth of new blood vessels. The recommended dose for treating glioblastoma is 10 mg/kg by IV every 2 weeks.

Genentech is also pursuing an FDA approval to use the drug to treat late-stage kidney cancer.

Reviewed by: Members of the ACS Medical Content Staff