Breast Cancer Drug Avastin Meets Latest Study Goals

One in eight women will be affected by breast cancer during their lifetime. No one knows why some women get breast cancer; certain changes in DNA can cause normal breast cells to become cancerous. However, scientists have discovered that in order for cancers to grow, blood vessels must be made to “feed” the cancer cells. New drugs have been developed that may be useful in stopping breast cancer growth by targeting and inhibiting the function of a natural protein called “vascular endothelial factor” (VEGF) that stimulates new blood vessel formation, a process known as angiogenesis. Angiogenesis inhibitors have been studied for three decades with the hope they might prevent the growth of cancer—and today those hopes are one step closer to becoming reality.

In February, the FDA provisionally approved Genentech’s Avastin, in combination with the chemotherapy drug paclitaxel, for the treatment of new cases of breast cancer, providing the drug maker files additional data. Their most recent findings come from the 1,237-patient Phase III study, called RIBBON 1, which was comprised of two independently-powered study groups evaluating Avastin or placebo in combination with either taxane, anthracycline-based or capecitabine chemotherapies in patients with metastatic HER2-negative breast cancer who had not previously received chemotherapy treatment.

Genentech recently announced that Avastin met its primary endpoint of progression-free survival or PFS in both groups, assessed by the treating physicians in the study. The safety profile of Avastin was also consistent with previous experience and no new safety signals were observed, Genentech noted. “This is really important news for breast cancer patients and physicians,” said William M. Burns, CEO Division Roche Pharmaceuticals (Genentech’s primary stockholder). “This study proves that patients benefit when Avastin is combined with commonly used chemotherapy which will give physicians more flexibility when selecting the most appropriate course of Avastin-based therapy for their patients.”

Genentech said a full review of the data will be submitted to the FDA in hopes of garnering their full approval of the drug for advanced breast cancer. Furthermore, the company said, as a part of its commitment to fully evaluate Avastin in breast cancer, it would submit to the FDA data from three additional randomized trials that are either ongoing or planned. “We look forward to discussing these data with the FDA and are committed to securing full FDA approval of Avastin based on the totality of data in advanced breast cancer,” Hal Barron, Managing Director, senior vice president, Development and chief medical officer, said in a statement. “We plan to submit the data from RIBBON 1 and AVADO to the FDA by mid-2009.”

Data from the E2100 study, which formed the basis of Avastin’s approval in Europe in March 2007, showed that women with metastatic breast cancer have the chance to live twice as long without their cancer advancing if treated with Avastin in addition to paclitaxel, compared to paclitaxel alone. Data from the AVADO study has shown that Avastin increases progression-free survival and response rate (shrinkage of the tumor) when combined with docetaxel, compared with docetaxel alone.

Avastin is also approved for use in advanced colorectal, lung and kidney cancer. To date, Avastin has been used to treat more than 350,000 cancer patients. Its anti-cancer benefits are also currently being assessed in 20 cancer types in various stages through a global clinical trial program including more than 40,000 patients around the world.