With the cancer drug Avastin on the ropes after losing FDA support for the treatment of breast cancer two years ago and an increasing chorus of criticism, an MD Anderson researcher has weighed in on where he thinks the drug’s effectiveness lies.
In a recent cancer study conducted at MD Anderson for the initial treatment of glioblastoma, one of the most deadly forms of brain cancer, Dr. Mark Gilbert, the study’s leader, found that the use of Avastin might not be best-suited for initial treatment options. In Dr. Gilbert’s study, 637 patients received standard chemotherapy plus radiation, while half also received Avastin. Both groups lived approximately 16 months — Avastin did not substantially extend the life expectancy or cure rate of test subjects — and yet those who received Avastin encountered more side effects, such as low blood counts, blood clots, and high blood pressure.
Dr. Gibert concluded, ‘‘Our study would strongly suggest that it is not beneficial to do it as front-line treatment but to reserve it as second-line or salvage therapy.’’
For as much as Dr. Gilbert’s findings for Avastin were middling at best, his opinion of Avastin’s effectiveness is ambivalent compared to other researchers around the world who have increasingly polarized opinions of whether or not the drug is indeed effective. In theory, Avastin’s approach to fighting cancer — cutting off blood supply to tumors — is a promising one, which led many researchers to believe early on that the drug would pave the way for the next generation of cancer treatment.
The realities, however, have not proven to be nearly as promising.
In addition to a much higher rate of side effects, Avastin has generally not proven to aid survival rates. In researching genetic tests on patients who were treated with the drug, the tests revealed that Avastin test subjects actually had a lower survival rate of 16 months versus 25 months for others. These findings have been generally true for both brain and breast cancer patients who used the drug, which is why the FDA pulled its use for breast cancer. Now, its approval for brain cancer might also be in jeopardy.
According to the Boston Globe:
The drug is approved for treating brain tumors that have recurred for people who already tried chemotherapy or radiation. But that approval was based on studies suggesting it briefly delayed the worsening of the disease. No definitive study shows it helps those patients live longer, either.
For as much as the data and justification for keeping Avastin on the shelves might seem thin at best, there are still cancer treatment providers and researchers alike who believe that the drug has some place in brain cancer treatment. In addition to Dr. Gilbert’s assessment above, Dr. Deepa Subramaniam, director of the brain tumor center at Georgetown Lombardi Comprehensive Cancer Center in Washington, D.C., recently commented that, ‘‘I would definitely not want the FDA to take that away from patients. That’s very different from the breast cancer story,’’ eluding to the fact that there are fewer effective drugs for treating serious brain cancer such as glioblastoma.
In the end, what might mitigate the FDA’s decision to continue the approval of Avastin’s use in the treatment of brain cancer is that it may offer some small degree of hope for the most serious cases of the disease. In many cancer trials, even a slight increase in the survival rate for the most deadly cancers is deemed “effective” by the medical community. While the data thus has not shown Avastin to provide even that small sliver to extra hope, if prominent researchers feel that the drug still has some use, their opinions are likely to have a palpable impact on the future of Avastin in medicine.