Adding bevacizumab to first-line (initial) chemotherapy and radiation treatment for glioblastoma is not recommended, based on this study's findings.
The phase III trial found that the medication did not improve survival and caused more side effects than standard of care chemotherapy and radiation.
As a result of these findings, the researchers suggested that bevacizumab should not be used in the initial treatment of glioblastoma, the most common form of brain cancer.
"Make sure you know why you’ve been prescribed a medication."
Mark R. Gilbert, MD, a professor of neuro-oncology at The University of Texas MD Anderson Cancer Center in Houston, Texas, led a study involving 637 patients newly diagnosed with glioblastoma, an aggressive brain cancer.
Patients were randomly assigned to receive either bevacizumab or a placebo.
Once the disease progressed, patients taking a placebo were allowed to cross over and receive the medication.
Adding this medication did not improve survival.
Individuals taking bevacizumab did have longer periods before the disease got worse (progression-free survival, or PFS). This three-month difference was not seen as statistically significant.
Patients in the bevacizumab-treated group had more serious side effects, including blood clots, low platelet count and high blood pressure, than did their peers who didn’t receive the medication.
The researchers found patients treated with bevacizumab also experienced more declines in cognitive function.
Interestingly, Avastin is approved to treat glioblastoma that has returned.
“Bevacizumab remains an important part of our armory against glioblastoma, but in most situations it should be reserved as a salvage regimen,” Dr. Gilbert said in a press release.
"The relevant result is that the upfront use of bevacizumab is not indicated,” Dr. Gilbert said.
“These results highlight the challenge in developing an effective treatment for glioblastoma,” renowned brain cancer expert Keith L. Black, MD, told dailyRx News.
“Because the tumors utilize many molecular pathways, therapies designed to block one pathway have not met with great success. To develop effective treatments for glioblastoma, we need a better understanding of how to block multiple pathways and prevent the tumor from outmaneuvering these barriers. And our multilateral approach must be designed to minimize toxicity to normal tissues and body systems,” said Dr. Black, who is chair and professor of Cedars-Sinai’s Department of Neurosurgery, director of the Cochran Brain Tumor Center, director of the Maxine Dunitz Neurosurgical Institute and the Ruth and Lawrence Harvey Chair in Neuroscience.
Dr. Black was not involved in this study.
This study was presented at the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting. This research was supported by the National Cancer Institute and Genentech, the manufacturer of Avastin.
The authors disclosed various financial relationships with Novartis, EMD Serono, Genentech, Merck (manufacturer of temozolomide), GlaxoSmithKline, Castle Biosciences, Roche/Genetech and Accuray.
All research is considered preliminary before it is published in a peer-reviewed journal.