News of the agreement comes just two days after Sprout’s drug Addyi (flibanserin) – a treatment for low sexual desire in premenopausal women – was approved by the US Food and Drug Administration (FDA).
Canada-based Valeant will pay Sprout co-founders Cindy and Robert Whitehead $500m when the deal completes later this year, a further $500m in the first quarter next year and share of future profits.
Valeant said; "Cindy Whitehead, Chief Executive Officer of Sprout, will join Valeant to lead this division dedicated to the introduction and global commercialization of Addyi, reporting to Anne Whitaker, Executive Vice President and Company Group Chairman."
It added that Sprout will retain its headquarters in Raleigh, North Carolina where it currently employs 34 staff.
Addyi history
The active pharmaceutical ingredient (API) flibanserin was developed by German drugmaker Boehringer Ingelheim, which originally intended to market it as a treatment for depression.
However, in 2009 a Phase III trial reported at the (appropriately named) congress of the European Society for Sexual Medicine, showed women on the drug had experienced a statistically significant increase in “satisfying sexual events,” (SSE) versus the control group.
Despite this, Boehringer failed in its efforts to get the drug approved for this indication. In 2010 the US FDA rejected it on the basis that it was ”no better than placebo” at treating hypoactive sexual desire disorder (HSDD).
The German company abandoned development of flibanserin later that year, subsequently selling it to Sprout in 2011.
Sprout’s first effort to get the drug approved in 2013 was unsuccessful after the FDA said its risks – fatigue, nausea and dizziness – outweighed its benefits.
Undeterred, Sprout launched a campaign called “even the score” alleging that the FDA’s decision indicated an underlying gender bias on the basis that the agency has approved 26 drugs for male sexual dysfunction.
These claims are disputed by the National Women’s Health Network which appealed to the US FDA committee tasked with reviewing the drug for a third to use “evidence-based decision making.”
Approved
Despite this opposition, flibanserin was approved by the FDA on Tuesday by 18 votes to 6.
The agency insisted that the drug carry a warning that it can cause low blood pressure – particularly if combined with alcohol.
Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research (CDER), said: “Because of a potentially serious interaction with alcohol, treatment with Addyi will only be available through certified health care professionals and certified pharmacies.”
Raghuram Selvaraju, managing director of brokerage H.C. Wainwright & Co, has estimated peak sales of $100m for Addyi, which is a fraction of the $1.7bn Pfizer's Viagra earns each year.