Novartis Corporation Issues Breast Cancer Drug Warning

A drug used to increase a woman's chances of becoming pregnant may cause birth defects and miscarriages, according to a safety alert issued Monday by Canadian health regulators. The drug letrozole, marketed under the brand name Femara, is approved to treat breast cancer in women who've undergone menopause. But doctors in the United States and Canada often prescribe it "off-label" to prompt ovulation as part of fertility treatments. Health Canada, the government national health care agency, and Swiss drug maker Novartis have sent letters to Canadian doctors warning them about the off-label, or unapproved, use of the drug. Health Canada posted copies of the letter and a patient safety alert on its Web site on Monday. Although the U.S. Food and Drug Administration isn't requiring it, Novartis will send a similar letter to U.S. fertility specialists to remind them that Femara is approved only as a breast cancer treatment, said Kim Fox, a Novartis spokeswoman. FDA officials were unavailable for comment Monday. Femara's official FDA prescribing information targeted at doctors warns that the drug may harm the fetus when prescribed to pregnant women, citing studies in rats. "If there is exposure to letrozole during pregnancy, the patient should be apprised of the potential hazard to the fetus and potential risk for the loss of pregnancy," the warning states.