Abbyi, the first drug approved to enhance women’s libido, was launched in September to both accolades and objections, but in the subsequent months has been prescribed to only 227 women. Bremelanotide, a competitor in Phase III clinical trials, may offer a better alternative for women suffering from low libido.
Addyi (flibanserin) was recently approved in the United States, becoming the drug that launched a thousand blog posts. The result of nearly a decade of research by Sprout Pharmaceuticals, Addyi was approved by the FDA to treat hypoactive sexual desire disorder in premenopausal women. Currently, it is the only drug approved in the United States to treat this condition, estimated to affect 8 million women in a market potentially worth over $2 billion. However, a challenger to Addyi is moving in to Phase III clinical trials and could represent a significant threat. The new agent, called bremelanotide, would be a take-as-needed injectable drug and, depending on the outcomes of these new trials, could easily outpace the sales of Addyi, projected by Decision Resources Group to reach only $100 million by 2018.
- Addyi (flibanserin) is anticipated to struggle in achieving favorable insurance coverage, and the inconvenience of daily dosing combined with the side effect profile will significantly restrict its sales.
- Bremelanotide was equally effective in increasing the number of satisfying sexual events in Phase II clinical trials, and the take-as-needed dosing of bremelanotide would be an advantage in competing against Addyi.
- If bremelanotide can hold up in Phase III clinical trials, it has the potential to equal or surpass Addyi’s sales.
Results from a Phase II clinical trial on bremelanotide are already available, and when compared to placebo this drug results in the same increase in the number of satisfying sexual events as Addyi achieved in Phase III trials. Bremelanotide is a subcutaneous formulation, and women would self-administer the drug as they desire, rather than adhering to the strict dosing schedule required by Addyi; this could be a major advantage in the marketplace, especially as it would be easier to avoid the negative side effects noted for both drugs. Addyi’s side effect profile includes nausea, fatigue, headache, dizziness, and sleepiness, with up to 75% of patients in trials reporting at least one adverse effect. Additionally, the FDA required a black box warning that prohibits using alcohol while taking Addyi, a major challenge for patients taking a daily lifestyle drug. While the number of patients suffering from side effects is marginally lower (68% in the high dosing group) for bremelanotide, it has an arguably worse side effect profile which includes vomiting, diarrhea, abdominal pain, and ironically breast tenderness and genital discomfort, likely negating the libido-enhancing impact of the drug in those who experience these particular consequences.
A phase III program for bremelanotide, sponsored by Palatin Technologies, is currently recruiting participants. The Reconnect Study aims to recruit over 1000 women in the United States and is forecasted to end in the summer of 2017. If bremelanotide is able to equal or surpass Addyi’s improvements in the number of self-reported satisfying sexual events, a bar set fairly low, Decision Resources Group forecasts this agent to launch by 2018 and reach the $100 million mark within 4 years, approximately the same time frame anticipated for Addyi. However, by the time bremelanotide comes to the market Addyi will have had two years to establish and expand a market for pharmaceutical treatment of sexual desire in women, and payers will have had time to decide how to cover this novel class of drugs. It is possible that following Addyi, bremelanotide could achieve orgiastic commercial success, but until clinical trial results become available, forecasting sales anything like those of Viagra or Cialis is likely premature.
A more in-depth comparison of drugs designed to treat sexual disfunction. http://www.the-scientist.com/?articles.view/articleNo/40272/title/That-Loving-Feeling/
Reports of the sales of Addyi on Bloomberg:http://www.bloomberg.com/news/articles/2015-11-17/valeant-s-newest-problem-the-female-libido-pill-isn-t-selling
Forecast numbers are taken from Decision Resources Group’s Pharmaview, available at https://biopharma.decisionresourcesgroup.com/Home