Should New Estrogen Carry Warning in Labeling?
Portyansky, Elena, Drug Topics
Almost flawless in its way of targeting some tissues while leaving others alone, Evista (raloxifene), the first designer estrogen to emerge for the prevention of osteoporosis in postmenopausal women, has been widely embraced. But there is one exception-Samuel Epstein, M.D., chairman of the Cancer Prevention Coalition and professor of environmental medicine at the University of Illinois. After reviewing raloxifene's data, he came across carcinogenesis studies conducted by raloxifene's manufacturer (Eli Lilly), which he feels warrant a warning to women-at the very least.
In the 21-month study, female rodents exposed to various doses of the selective estrogen receptor modulator (SERM) were found to have an increased incidence of ovarian tumors. Systemic exposure (AUC) of raloxifene in the animals ranged from 0.3 to 34 times that found in postmenopausal women administered a therapeutic dose of 60 mg.
The study concluded that the clinical relevance of these tumor findings is unknown. Epstein doesn't agree and voiced his viewpoint on the Jan. 12 "Jim Lehrer Newshour" on public television. He believes these results create a strong presumption of human risk of ovarian cancer, since carcinogenic effects occurred in two animal species and at doses extending below the therapeutic range. He is outraged that raloxifene's manufacturer failed to disclose a notice to that effect in its warning section of product labeling. This drug, Epstein continued, "should be withdrawn from the world market immediately, and a cancer alert should be sent to the more than 12,000 women who have participated in U.S. and international clinical trials. These women should also be offered lifelong biannual surveillance for the early detection of ovarian cancer at Lilly's expense."
Willard Dere, M.D., director, medical (endocrine research), Eli Lilly, countered that the observations seen in the reproductive-age rodents are not applicable to, or predictive of, what occurs in postmenopausal women, since the subjects' hormonal backdrops differ. …