FORBES AUSTRALIA – A single oral dose of the drug immobilised mice sperm for up to two and a half hours and was 100% effective in the first two hours, the researchers said.
Treated mice showed normal mating behaviour but none impregnated a mate despite 52 different attempts to do so, the researchers said, compared to almost a third of mice impregnating mates after being treated with an inactive control substance.
The drug is fast-acting—Melanie Balbach, one of the study’s authors and a researcher at Weill Cornell Medicine, said it worked within 30 to 60 minutes—and works by inhibiting an enzyme needed for sperm to function.
It is also temporary, with efficacy dropping to 91% at three hours and fertility returning to normal by the next day.
These properties set the drug apart from many of the other efforts to develop a male contraceptive, the researchers said, which often rely on hormones to control fertility and can take weeks or months to be effective or to wear off.
“The next step will be to repeat the experiment in a different animal model.”
The study demonstrates proof-of-concept for “safe, non-hormonal, on-demand, male contraceptives,” the researchers said, and while it may work in theory any product will be many years and a great deal of testing in the future.
What To Watch For
The discovery is a “game-changer” in the quest to develop another form of contraception for men, said Jochen Buck and Lonny Levin, pharmacology professors at Weill Cornell Medicine and senior authors of the study.
The pair launched their own company, Sacyl Pharmaceuticals, to develop contraception based on the inhibitors and said the next step will be to repeat the experiment in a different animal model.
Buck said this would “lay the groundwork for human clinical trials” and Levin said the team is already working to create inhibitors that would be “better suited for use in humans … ”