A team of scientists announced on Wednesday March 23 that they had developed a male contraceptive pill that is 99% effective in mice without causing any visible side effects, and which could be tested on men by the end of the year.
These results are to be presented at the Spring Conference of the American Chemical Society.
They mark an important step for male contraception, which remains very marginal within couples.
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The search for a birth control pill for men dates back as far as the authorization in the 1960s of its equivalent for women, Md Abdullah Al Noman, a master's student at the University of Minnesota, told AFP. , who will present this work at the conference.
"Many studies show that men are interested in sharing the responsibility for contraception within the couple,"
he says, but only two effective and recognized solutions exist to date: condoms and vasectomy - a lasting solution. on which it is sometimes complicated (and expensive) to come back.
Other practices, such as heated briefs and the ring around the testicles, remain confidential and not validated by the health authorities.
The functioning of the female pill is based on hormones that disrupt the menstrual cycle.
Researchers have long tried to develop a male equivalent using the same method and acting on a male hormone, testosterone.
But these attempts caused unwanted side effects such as weight gain, bouts of depression and increased cholesterol levels, which increases the risk of heart disease.
The female pill also causes side effects -- including an increased risk of blood clots.
There's no guarantee of success... but I'd be really surprised if I didn't see an effect on humans as well.
»
Professor Gunda Georg
To develop a non-hormonal pill, Md Abdullah Al Noman, who works in Professor Gunda Georg's lab, targeted a protein, the retinoic acid receptor alpha (RAR-alpha).
In the human body, vitamin A is transformed into many elements including retinoic acid, which plays an important role in cell growth, sperm formation and embryo development.
Retinoic acid needs these RAR-alpha receptors to act: laboratory experiments have shown that mice deprived of the gene which encodes this receptor are sterile.
For its work, this laboratory has developed a compound that blocks the action of RAR-alpha.
The researchers used a computer model to identify the best possible molecular structure.
Their chemical compound, named YCT529, was designed to interact only with RAR-alpha, and not with two other neighboring receptors, RAR-beta and RAR-gamma, to limit side effects.
Orally administered to male mice for four weeks, YCT529 drastically reduced sperm production and was 99% effective in preventing pregnancy, with no side effects observed.
And six weeks after stopping the ingestion of YCT529, the mice could reproduce again.
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The team, funded by the US Institutes of Health (NIH) and the non-profit Male Contraceptive Initiative, is working with YourChoice Therapeutics to begin clinical trials in the second half of 2022, the professor said. Gunda Georg.
"I think it can move forward quickly
," she said, estimating that commercialization could occur within five years.
"There is no guarantee of success... but I would be really surprised not to observe an effect also on humans
," added the chemist.
Would women, however, trust men enough to take on a matter that has hitherto been almost entirely up to them?
Studies have shown that the majority of women would be willing to rely on their partner, and a significant number of men have reported being willing to take birth control pills.
“Male contraception will be added to existing choices and will allow men and women to choose the contraceptive method that seems most appropriate to them
,” welcomed the Male Contraceptive Initiative.