Flurry of Year-End FDA Activity
The U.S. Food and Drug Administration (FDA) has just issued a flurry of year-end approvals, including giving the green light to some important breast cancer treatments, but also deferring some controversial decisions until 2001. Here is a sampler ...
Two FDA rulings directly affected testing for the HER-2/neu gene, which is thought to play a major part in breast cancer progression. Studies have shown that HER-2/neu is present in as many as 30 percent of breast cancer cases.
Bayer Diagnostics received FDA approval to market a test for monitoring patients with metastatic breast cancer (disease that has spread). The test measures the levels of HER-2/neu in blood serum, considered a key indicator of aggressive disease in certain women. The test could also be important for assessing whether a patient is responding to certain therapies—most notably Genentech’s Herceptin (trastuzumab).
(Herceptin was one of the first gene-based cancer drugs to be brought to market. It works by inhibiting the growth of the HER-2/neu protein, which is often present in large amounts—"overexpressed"—in women with metastatic breast cancer.)
Similarly, the FDA approved a Ventana Medical Systems antibody—Pathway Her 2—that also tests for overexpression of HER-2/neu. The company said its antibody would not only assess the aggressiveness of the disease, but would also help determine which patients with breast cancer should undergo Herceptin therapy.
An advisory panel to the FDA gave its unanimous approval to Novartis AG’s Femara (letrozole) as a first-line (initial) treatment for women with metastatic breast cancer. The FDA’s Oncologic Drugs Advisory Committee said Femara acts by blocking estrogen production. The FDA usually follows its advisory panels’ advice.
Femara was initially approved by the FDA in 1997 as a second-line treatment for women with advanced, estrogen-sensitive disease that did not respond to initial treatment. However, this recent approval enables oncologists to prescribe Femara as a first attempt to bring the disease under control.
That same panel, the Oncologic Drugs Advisory Committee, also came under fire from patient advocacy groups about a lack of access to unapproved, yet promising, cancer drugs. In a public hearing, the committee—and the FDA as a whole—were lambasted for not forcing drug manufacturers to make promising new drugs available to severely ill patients—even if these drugs are still in the clinical trial review process.
Expanding such "compassionate use" access might save the lives of thousands of people battling advanced disease, patient advocacy groups argued. However, drug industry spokesmen countered that expanding such unofficial access would severely limit their ability to enroll patients in clinical trials—already an extremely difficult task.
The Advisory Committee has until March to issue its recommendation, which will surely add further controversy to this already contentious debate.
The FDA postponed a decision on whether to allow vitamin labels to claim that antioxidants have cancer-fighting benefits. The label at issue read, "Consumption of antioxidant vitamins may reduce the risk of certain kinds of cancers."
Missing its own self-imposed December 22 deadline, the agency said it needed more time to evaluate the extensive amount of research that has attempted to evaluate the effectiveness of antioxidants in preventing cancer.
Back in 1990, as part of the Nutrition Labeling and Education Act, Congress asked the FDA to determine the validity of the claim that antioxidants reduced the risk of certain cancers. The agency soon ruled that there wasn’t enough scientific agreement that antioxidants indeed had a significant impact on risk.
However, immediately after the FDA ruling, a consortium of dietary supplement makers filed suit, alleging that the FDA didn’t evaluate the scientific data correctly. The FDA was subsequently ordered by a federal appeals court to go back and re-examine the antioxidant claim.
The agency, citing "the large number of new human studies that were conducted since FDA’s original 1991-93 review," set a new deadline for February 23, 2001.
Finally, although not related to the FDA, another government agency issued an important approval—for Medicare to pay for PET scans (positron emission tomography) to help diagnose and treat a wide range of cancers. The Health Care Financing Administration (HCFA) had previously approved PET scans for only a very narrow range of uses.
PET scans use a radioactive tag that can show how much glucose cells are using. In the case of cancer, tumor cells use extra glucose, meaning that PET can spot tumors very early in their development. PET can also tell a doctor how a tumor is responding to treatments.
Because PET technology is so new, Medicare has been cautious about giving its approval. However, after considerable lobbying from cancer advocates and industry specialists, HCFA relented. Its decision will enable tens of thousands of patients on Medicare to finally have access to the technology.
SOURCES:
U.S. Food and Drug Administration (http://www.fda.gov)
Health Care Financing Administration (http://www.hcfa.hhs.gov)
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