R&D: Male Contraceptives in the Pipeline
The idea of male contraception has been around for 60 years. Gregory Pincus, the co-inventor of the female contraceptive pill, tested the same hormonal approach on men in 1957, and various hormonal and non-hormonal methods have been explored since. Based on side effects and other research complications, there are still only two reliable, non-hormonal contraceptives on the market for men today: condoms and vasectomy.
Female hormonal contraception is based on interruption of the menstrual cycle. Because sperm are produced continuously, there is no similar cycle to interrupt. Much of the early research on male contraceptives instead focused on a fully reversible halt to sperm production. Unfortunately, all the compounds that were discovered which stopped sperm production had some fatal flaw exposed before they could get to market, such as severe side effects or not being reversible in some men.
These days, researchers are exploring altering sperm function rather than stopping sperm production. Examples of functional changes include keeping sperm from swimming or from being able to fertilize an egg.
Today’s R&D Pipeline
The good news is that there are many potential targets and methods for male contraception. Here are a few that show exceptional promise.
There are two herbals in development, and one is in clinical trials in Indonesia. Gendarussa (sometimes spelled gandarusa) is a natural product extracted from the Justica gendarussa plant, and is native to China. It’s thought that the herbal works by disrupting the interaction between the sperm and ovum during fertilization.
A research team at Airlangga University in Surabaya, Indonesia is leading the charge to develop Gendarussa in collaboration with MCI and FHI 360 to demonstrate the efficacy and safety of the herbal extract.
Recent studies have shown that male reproductive function is modulated via a protein kinase enzyme cascade. A startup called Vibliome, in collaboration with researchers at University of Montana and Stanford University, is developing a new family of therapeutics based on these promising kinase targets and their escape pathways. The compounds were originally discovered for the treatment of cancer, and researchers were able to isolate the mechanism of action on the HIPK4 male reproductive target and its escape pathway. MCI has funded initial research in this area.
Vas-occlusives are a kind of polymer injected into the vas deferens that physically block the transport of sperm. Vasalgel and Contraline are two current products in development that work via an injection of a hydrogel polymer into the vas deferens, which allows fluid passage but not sperm flow. Vas-occlusive polymers are reversible with a second injectable, which dissolves and flushes the polymer. Both products are in early development with hopes for full clinical trials in the near future.
Clean Sheets Pill
Yes, it’s how it sounds. A pill a man could take that prevents ejaculation without affecting his orgasm, allowing for sexual pleasure but no wet spot.
The Clean Sheets Pill is based on the common drug phenoxybenzamine, which is used to treat conditions like schizophrenia and high blood pressure. Researchers in the United Kingdom noticed that one of the side effects of this drug is to block ejaculation by closing the tubes in the epididymis and vas deferens, preventing the passage of semen. The semen remains in the tubes and is naturally recycled by the body. Blocking ejaculation has another benefit—the Clean Sheets Pill could prevent the transmission of HIV and other STIs from an infected person to another during sex.
Most of these products are in the early stages of identifying the drug compound and the mechanism of action. It will be at least 12 years after solid identification to develop the new drug through clinical trials to market approval by the FDA. As the saying goes, “The best time to plant a tree is 20 years ago. The next best time is today.”
To stay up to date on new research and developments in male contraception, visit the R&D Pipeline at Male Contraception Initiative.
This blog series is a collaboration with FHI 360 and can also be found on the CTI Exchange.