Washington, DCA cancer drug that was fast-tracked for approval by the US Food and Drug Administration (FDA) in 2008 for the treatment of metastatic breast cancer will have that approval revoked, the agency announced yesterday. The decision follows the recommendation by an expert panel in July that voted 12-1 to reverse the approval of Avastin for metastatic breast cancer.
The reason? Recent studies have shown that the benefits for metastatic breast cancer are no longer considered to outweigh the risks. Avastin, which was originally approved as a cancer treatment in 2004, will have its indications for the treatment of various cancers involving the lung, kidney, brain and the colorectal system remain intact.
According to a CNN report late yesterday, Dr. Janet Woodcock of the FDA's Center for Drug Evaluation and Research, noted that patients currently being treated with Avastin for metastatic breast cancer will not be affected, and "doctors should use their medical judgment on whether to continue" its use, she said.
Avastin works by choking off the blood supply to the tumor, and was granted accelerated approval as an indication for breast cancer in 2008, based on a single study dubbed E2100. The preliminary study found that Avastin, when used in combination with other drugs, extended the time that patients went without their illness getting worse, a measure known as progression-free survival, or PFS.
While the results were encouraging, the FDA required the manufacturer of Avastin, Genentech, to undertake more involved studies in an effort to verify the findings of the preliminary, E2100 study.
As it turned out, the benefits when weighted against the larger studies were much less promising for metastatic breast cancer, the researchers found. Initially, the E2100 study determined that for women taking Avastin plus paclitaxel, the cancer stopped spreading for an average of five-and-a-half months more, compared to those just taking standard chemotherapy. However, the three subsequent studies found the benefit to be much smaller, ranging from 24 days to two months.
What's more, all four studies including the preliminary E2100 study showed that patients receiving Avastin for metastatic breast cancer failed to live longer than other patients receiving more standard versions of chemotherapy.
"We now have four studies that show no survival benefit,"
Woodcock said.
Then there are the side effects—among them high blood pressure, internal bleeding, perforated internal organs, heart failure and heart attacks, and in some cases, swelling of the brain.
Based on this data, the advisory panel voted in July to reverse the accelerated approval of Avastin for metastatic breast cancer, and the FDA is following the expert panel's lead. Genentech has the right to appeal that decision and signaled it would request a hearing.
"This is a very sad and confusing day for our patients," said Dr. Joseph Sparano of Montefiore-Einstein Center for Cancer Care in New York Medical Center. "Survival was consistently better at one year in all of the studies, indicating that this is a safe and effective option. What makes this even more frustrating is that the drug will still be available to prescribe, but will only be an option for those who can afford it rather than those who really need it."
The costs for Avastin can run to several thousand dollars a month, although the FDA stresses that it does not take cost into account when evaluating a drug for safety or efficacy.
Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, said in a statement posted on the Web site of the American Cancer Society that it's clear "some women with metastatic breast cancer have benefited from Avastin, but others not only have not benefited, they've been harmed.
"What we clearly need is a way for doctors to more accurately predict which women will have a better chance of benefitting from this important targeted therapy."
As for women now having to deal with the potential loss of a promising drug, the emotional rollercoaster just became all that much more difficult.