Business your connection to The Boston Globe

FDA backs birth control pill that halts periods

NEW YORK -- Wyeth won U S approval for its contraceptive Lybrel, the first birth control pill designed to completely eliminate monthly periods.

The Food and Drug Administration said yesterday that it has cleared the daily pill after delaying a decision 11 months ago to get more data on pregnancy rates and bleeding patterns in users. Lybrel will go on sale in July, Wyeth said.

The pill makes Wyeth the challenger to Barr Pharmaceuticals Inc., the biggest U S maker of birth-control pills, in the market for contraceptives that limit menstruation. Lybrel may generate $250 million a year, Madison, N.J.-based Wyeth said. Barr's Seasonale, the first pill to reduce periods to four a year, had sales of $100 million in fiscal 2006.

"Lybrel may drive growth in this class of drugs that limit monthly periods," said Ken Cacciatore, an analyst with Cowen & Co.

The FDA postponed a decision on The drug caused bleeding or spotting as a side effect in about 65 percent to 70 percent of women in trials, although the number decreased over the first year of use, said Daniel Shames of the FDA Office of Drug Evaluation III.

"Each woman and their health care provider will have to look at the label and decide if this form of contraception is appropriate," Shames said.

The first oral contraceptives went on the market in the 1960s and were designed to mimic monthly periods so women and doctors would feel more comfortable with birth-control pills, said Rachel Jones, a senior researcher at the Guttmacher Institute, a reproductive health policy group.

"There was no medical reason to have a period every month," Jones said. "It was to reassure women and make them feel natural taking birth control."

Lybrel contains low doses of the hormones found in most oral contraceptives. Risks of all birth-control pills include blood clots, heart attacks, and strokes, particularly in smokers.