Jan. 10, 2001 (Washington) -- The FDA announced Wednesday the approval of Femara as a first-line therapy for postmenopausal women with advanced breast cancers with estrogen-dependent tumors. In clinical trials, it proved even more effective than the blockbuster drug tamoxifen, the current standard of care in such cases.
Femara works by inhibiting the synthesis of estrogen, a hormone that promotes the growth of some breast cancers. In 1997, it was approved as a second-line treatment following the use of other anti-estrogen drugs.
According to the FDA, the approval was based in part upon a pivotal study of about 900 women, in which Femara was "shown to be more effective than tamoxifen." Study results show that Femara slowed disease progression by an average of 3 months over tamoxifen.
Furthermore, more cancers responded to Femara than to tamoxifen, says Gloria Stone, a spokeswoman for Novartis Pharmaceuticals, the maker of Femara. The total response rate to Femara was approximately 30% vs. about 20% for those patients on tamoxifen, she tells WebMD.
The side effect profile for the two drugs is similar, the FDA notes. The most frequently reported side effects for both groups were bone pain, hot flashes, back pain, nausea, joint pain, and labored breathing.
The FDA approval of Femara follows the recommendation of an expert FDA advisory committee, which unanimously backed its approval in December. The committee voted to support its approval despite the lack of clear data showing that Femara actually helps women survive longer.
But the advisory committee was swayed by the argument that advanced breast cancer cannot be cured, thus, preventing the disease from progressing might be the best way to evaluate whether a drug has any clinical value.
"FDA approval of this new indication [for Femara] means that thousands of postmenopausal women with advanced breast cancer will finally have a more effective hormonal treatment option," says David Parkinson, MD, vice president of the drugmaker's cancer division.
Femara is the second in this new class of drugs, called aromatase inhibitors, to be approved after AstraZeneca's Arimidex. But Femara is the first aromatase inhibitor to demonstrate equivalence, if not superiority, to tamoxifen, according to its clinical investigators.
In fact, "Femara shows great promise for becoming the new first-line therapy of choice for postmenopausal women with advanced breast cancer," says Robert Smith, MD, who was a lead investigator in the clinical trials. "It is the first therapy to challenge tamoxifen in multiple endpoints, including time to progression, response rates, and overall clinical benefit."
The company presently is working on the label to reflect this latest approval, Stone says. And physicians should be receiving that clinical information within the next month, she tells WebMD.