Boehringer pulls the plug on "pink Viagra"

FRANKFURT (Reuters) – German drugmaker Boehringer Ingelheim has stopped developing a drug dubbed the "pink Viagra" after failing to convince U.S. regulators the experimental pill could boost women's sex drive.

"The decision was not made lightly, considering the advanced stage of development," chief executive Andreas Barner said on Friday of the hoped-for moneyspinner aimed at premenopausal women with a persistent and unexplained lack of sex drive.

Boehringer's move marked the failure of the latest attempt to find a female counterpart to Pfizer's Viagra, the blockbuster blue pill for men. Drugmakers have tested various ways to boost female libido, but women's sex lives have proved difficult to target with medication.

U.S. government advisers said in June that Boehringer's pink pill, based on the active ingredient flibanserin, offered little help to women and had unacceptable risks -- nearly 15 percent of women stopped taking a pill before a study ended due to side effects including depression, fainting and fatigue.

That led the U.S. Food and Drug Administration to ask unlisted Boehringer in August for more information on flibanserin, which would have been marketed as Girosa.

"The response of the authorities and the complexity and extent of further questions that would need to be addressed to potentially obtain registration for flibanserin have impacted the company's decision to focus on other pipeline projects," Boehringer said.

Drugmakers have been searching for a medicine to improve women's sex lives since Viagra's debut 12 years ago. The market for a "pink Viagra" could stretch into the billions of dollars.

NO MEDICINE FOR LIBIDO

Originally developed as an antidepressant, flibanserin was believed to act on brain chemicals that play a role in sexual response. But, in trials, women on the once-a-day pill, taken at bedtime reported unwanted side effects.

An FDA advisory committee voted 11-0 in June that the drug's risks and benefits were unacceptable and 10-1 that effectiveness data was lacking.

Boehringer, a 125-year-old company controlled by great-grandchildren of the company's founder, said it would now merely complete the two most advanced drug trials.

Male impotence pills including Viagra work by widening blood vessels to increase the blood flow needed for an erection. Pfizer dropped tests of Viagra in females in 2004 after studies failed to show it helped women.

The flibanserin setback was in contrast to Boehringer's success in pioneering a new blood thinning pill for a market that rival Bayer said could be worth $15 billion.

A U.S. advisory panel last month recommend clearance of Boehringer's Pradaxa pill for preventing strokes in patients with a type of irregular heart beat.[source]