Failed anti-depressant flibanserin reborn as female “Viagra”?

The findings, reported at the appropriately named congress of the European Society for Sexual Medicine, showed women on the drug experienced a statistically significant increase in “satisfying sexual events,” (SSE) versus the control group

In two of the main 24 week studies, Daisy and Violet, women treated with 100mg of flibanserin per day reported 4.5 SSEs per month from a baseline of 2.8, while those in the placebo group increased to 3.7 SSEs from 2.7 at the start of the trial

Additionally, women in those trials, as well as those in an equivalent European study known as Orchid, reported a significant increase in sexual desire. Boehringer plans to file flibanserin for regulatory approval in the next few months.

Change of indication​

Like Pfizer’s Viagra, which was first trialled as a medication for cardiac disorders, flibanserin was originally developed with another indication in mind, namely as a treatment for depression.

And, although flibanserin failed as a depression therapy, in another echo of the Viagra experience, women involved in the trials reported an increase in sexual activity and satisfaction.

As a result, in 2002 Boehringer began investigating flibanserin as a libido booster in pre-menopausal women suffering from hypoactive Sexual Desire Disorder (HSDD), culminating in the three Phase III studies reported on Monday.

Market demand​

Understandably perhaps, given both the market success of Viagra and the estimate that HSDD affects up to 25 per cent of women worldwide, the flibanserin trial results attracted a considerable amount of attention.

However whereas, rightly or wrongly, Viagra has gained a reputation as an “on demand” lifestyle drug, flibanserin’s libido boosting affects depend on a gradual build up over a number of weeks, so it may not see the same levels of demand.

Nevertheless, most observers agree that there is a significant market for a HSDD treatment, with estimates ranging from Decision Resources’ $100m a year valuation to the $3.5bn figure forecast by BioSante Pharmaceuticals’ CEO Stephen Simes.