Raloxifene wins approval for curbing breast Ca risk.
Eli Lilly, which markets raloxifene as Evista, announced the approval on Sept. 14. Raloxifene, a selective estrogen receptor modulator (SERM), is the second drug indicated to reduce the risk of breast cancer in women at high risk. Tamoxifen was the first. Raloxifene was approved for treating postmenopausal osteoporosis in 1999.
The Food and Drug Administration's Oncologic Drugs Advisory Committee in July backed the approval of raloxifene for the new indications; the vote in favor was 8 to 6 for reducing risk in women with postmenopausal osteoporosis, and 10 to 4 in women at high risk for breast cancer. The panel reviewed four large studies submitted by Eli Lilly: The Study of Tamoxifen and Raloxifene (STAR) trial; Raloxifene Use for the Heart (RUTH) trial; Multiple Outcomes of Raloxifene Evaluation (MORE); and the Continuing Outcomes Relevant to Evista (CORE) trials.
A boxed warning about an increased risk of venous thromboembolism and fatal strokes associated with raloxifene also has been added to the new label.
The approval "provides an important new option for women at heightened risk of breast cancer," Dr. Steven Galson, director of the FDA's Center for Drug Evaluation and Research said in a statement. "Because Evista can cause serious side effects, the benefits and risks of taking Evista should be carefully evaluated for each individual woman," he added.
"We welcome the approval of a second option" for reducing the risk of invasive breast cancer, said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society. Tamoxifen can reduce the risk for breast cancer in women at high risk, but "women and their clinicians have been reluctant to embrace this strategy," he said. This has been at least partly because treatment with tamoxifen is associated with an increased risk of thromboembolism and uterine cancer.
Raloxifene appears to have a more favorable safety profile and is more familiar to physicians because of its osteoporosis indications, so "we are hopeful it will be more accepted by patients and their doctors for this purpose," added Dr. Lichtenfeld, who is an adviser to INTERNAL MEDICINE NEWS.
The risk of invasive breast cancer was evaluated as a secondary safety end point in the MORE trial, a 3-year, international study of 7,705 postmenopausal women with osteoporosis. The incidence of invasive breast cancer was 71% lower in those on 60 mg of raloxifene per day, compared with those on placebo. This was primarily due to an 80% reduction in the incidence of estrogen receptor (ER)--positive invasive breast cancer in those on raloxifene.
In the CORE study, which followed for up to 8 years a subset of over 2,000 women enrolled in the MORE trial, the incidence of invasive breast cancer was reduced by 60% in women who continued with raloxifene, compared with placebo. This was primarily due to a 65% reduction in the incidence of ER-positive invasive breast cancer in those on raloxifene.
In the RUTH study, 12,101 postmenopausal women who had coronary heart disease or multiple (CHD) risk factors were given 60 mg of raloxifene per day or placebo for a median of 5.6 years. The rate of primary coronary events did not differ significantly between the two groups, but the risk of invasive breast cancer was reduced by 44% in those on raloxifene, compared with placebo. The decrease was primarily due to a 55% reduction in ER-positive invasive breast cancer in those on raloxifene (N. Engl. J. Med. 2006;355:125-37). However, 1.2% of the women treated with raloxifene had a fatal stroke, compared with 0.8% of those on placebo, which was significant. Raloxifene was associated with a greater risk of venous thromboembolism, but not with a difference in all-cause mortality.
When considering raloxifene for postmenopausal patients, "the clinician should take into account the individual woman's risk of disease and her personal preferences and weigh the potential benefits against risks and against the availability of alternative interventions," the authors said.
Based on the RUTH trial, the raloxifene label was updated in July to include a boxed warning stating that women with an active or past history of venous thromboembolism should not take raloxifene and recommending that prescribers consider the risk-benefit balance in women at risk for stroke.
The fourth study, the STAR trial, compared raloxifene 60 mg/day with tamoxifen 20 mg/day over 5 years, in almost 20,000 women in the National Surgical Adjuvant Breast and Bowel Project Study, whose mean age was almost 60. The incidence of invasive breast cancer was similar in the raloxifene group (4.4 per 1,000 women per year) and the tamoxifen group (4.3 per 1,000 women per year).
Other side effects associated with raloxifene include hot flashes, edema of the legs and feet, flulike symptoms, and sweating, according to the FDA.
BY ELIZABETH MECHATIE
|Printer friendly Cite/link Email Feedback|
|Publication:||Internal Medicine News|
|Date:||Oct 1, 2007|
|Previous Article:||Silent myocardial ischemia reversed in type 2 diabetes: outcome seen in 79% of affected patients.|
|Next Article:||Ounce of prevention can save lives.|