I want to share with you the latest news on Avastin® (bevacizumab), a treatment for patients with glioblastoma, the most common and aggressive form of brain cancer.
On November 17th, Genentech released the results of their Phase III clinical trial looking at the use of Avastin in newly diagnosed GBM patients. This was the first time interim results for overall survival (OS) were provided. The study showed that Avastin, in combination with radiation and temozolomide chemotherapy, reduced the risk of cancer worsening or death (progression-free survival; PFS) by 36 percent compared to radiation and temozolomide plus placebo in people with newly diagnosed glioblastoma. The interim results for overall survival, the other co-primary endpoint, did not reach statistical significance. The data were presented at the 17th Annual Meeting of the Society for Neuro-Oncology in Washington, D.C.
Click here for the Genentech press release.
From our perspective, the news on progression-free survival is positive. While we would also have liked to see a corresponding increase in overall survival (OS), the interim data showed no such increase. Final data on OS are expected in 2013. Avastin is currently being marketed under an accelerated approval by the FDA and Genentech/Roche will likely go back before the FDA with these data to get ongoing approval. To the best of our knowledge, no date has yet been set for such an action.
A big medical story last year was the FDA’s revocation of the accelerated approval of Avastin for advanced breast cancer. There, the clinical trials had shown that the drug was not helping breast cancer patients to live longer or to meaningfully control their tumors (different than announced data on GBM), and the FDA felt that the data showed that the use of Avastin exposed patients to potentially serious side effects like severe high blood pressure and hemorrhaging. That revocation decision by the FDA was quite controversial and there is an effort now underway to have Avastin re-approved for early stage breast cancer where the data is more convincing.
In the case of GBM, we have talked with our scientific friends and advisors and they believe that Avastin is an important part of the current limited treatment mix available. There is no other new GBM drug that has been able to show an improvement in overall survival and the physicians believe that in this environment a significant improvement in progression-free survival alone makes Avastin an important tool for them to be able to use in treating their patients. Also, there is some thinking that as Avastin is used in combination with a range of other treatments, we may see greater efficacy going forward. For now, what we have is a drug that has shown significant improvement in progression free survival for GBM patients and that alone is a good and important start.
As developments unfold, I will continue to keep you updated on this important issue to our community.