According to a new study published December 29 in The New England Journal of Medicine, bevacizumab (Avastin) may slow the progression of ovarian cancer; however, it remains questionable whether it significantly prolongs life. Another factor that must be measured is that the drug has been associated to serious side-effects in some women. Avastin opposes cancer growth by slowing angiogenesis—the development of new blood vessels. The proliferation of blood vessels is essential for cancer growth. Avastin is classified as avascular endothelial growth factor inhibitor.
The study group was comprised of 1,528 ovarian cancer patientsen from 11 nations who were randomly assigned to receive either carboplatin and paclitaxel given every three weeks for six cycles, or to this regimen plus bevacizumab given concurrently every three weeks for five or six cycles and continued for 12 additional cycles or until progression of disease.
The researchers found that progression-free survival at 36 months was 20.3 months with standard therapy, as compared with 21.8 months with standard therapy plus bevacizumab. Bevacizumab was associated with more toxic effects (most often hypertension; 18%, vs. 2% with chemotherapy alone). In the updated analyses, progression-free survival at 42 months was 22.4 months without bevacizumab versus 24.1 months with bevacizumab. In patients at high risk for progression, the benefit was greater with bevacizumab than without it, with progression-free survival at 42 months of 14.5 months with standard therapy alone and 18.1 months with bevacizumab added, with respective average overall survival of 28.8 and 36.6 months.
The authors concluded that bevacizumab improved progression-free survival in women with ovarian cancer. They also noted that the benefits with respect to both progression-free and overall survival were greater among those at high risk for disease progression.
It must be stressed that the study was funded by Roche, the manufacturer of Avastin, and the National Institute for Health Research, through the National Cancer Research Network.
On December 23, the European Commission approved the use of bevacizumab for a new indication: newly-diagnosed ovarian cancer. The approval is for use of Avastin as a first-line treatment together with standard chemotherapy, which includes carboplatin and paclitaxel, in women with advanced ovarian cancer. The approval was based on data from two clinical trials (ICON-7 and GOG 0218); these studies found that women who had Avastin added to their chemotherapy regimen and subsequently received Avastin alone experienced significantly-improved progression-free survival compared with those who received just the standard chemotherapy. (ICON: International Collaborative Ovarian Neoplasm; GOG: Gynecologic Oncology Group.)
In the United States, Avastin is approved for colon, lung, kidney, and brain cancers. In 2008, Avastin received accelerated approval for metastatic breast cancer under a program that allows drugs for serious diseases to reach the market quickly, subject to further study. In December 2010, the FDA stated that these later studies did not confirm the initial findings that Avastin was effective. The members of the advisory committee reported that the results from clinical trials suggested Avastin was not helping women; however, it was exposing them to potentially serious side effects including hemorrhages, high blood pressure, and gastrointestinal perforations.
The FDA’s focus is on safeguarding the public from imperfect drugs and food contaminants. The European Commission has a much broader scope; it is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union’s treaties and the general day-to-day running of the Union. With its broader scope, it is possible that the European Commission’s scrutiny of new pharmaceuticals is less thorough than that of the FDA.
Ovarian cancer is the third most common cause of cancer deaths in Los Angeles County women. Contributing to its mortality is the fact that it often is not diagnosed until it has progressed to an advanced, incurable stage. Its cause is unknown; however, older women are at highest risk. About two-thirds of the deaths from ovarian cancer occur in women age 55 and older. About 25% of ovarian cancer deaths occur in women ages 35 – 54.