A team of scientists reported on Wednesday (23) that they have developed a male contraceptive pill that has been shown to be 99% effective in mice without causing side effects. Human trials may begin by the end of the year.
The findings about this contraceptive will be presented at the American Chemical Society’s spring meeting and represent a milestone in offering birth control methods and responsibilities for men.
Ever since the birth control pill for women was approved in the 1960s, researchers have been interested in developing its male counterpart.
“Several studies show that men are interested in sharing contraceptive responsibility with their partners,” Dr. Abdullah Al Noman, a graduate of the University of Minnesota and in charge of presenting the research, told AFP.
So far, only condoms and vasectomy are among the effective methods available to men. In the case of vasectomy, reversible surgery is expensive and not always successful.
The female pill uses hormones to alter the menstrual cycle, and historic efforts to develop a male equivalent have focused on the hormone testosterone.
The problem with this approach, however, is that it has side effects like weight gain, depression, and increased LDL cholesterol levels, all of which raise the risk of heart disease.
The female pill also has side effects, including blood clotting risks, but given the possibility of becoming pregnant in the absence of a contraceptive method, the risk calculation is different.
To develop a non-hormonal method, Noman, who works in Professor Gunda Georg’s lab, focused on a protein called “retinoic acid receptor (RAR) alpha”.
In the body, vitamin A is processed in a number of ways, including retinoic acid, which plays an important role in cell growth, sperm formation, and embryonic development.
Retinoic acid needs to interact with RAR-alpha to develop these functions, and laboratory experiments have shown that mice lacking the gene created by the RAR-alpha receptor are sterile.
For their work, Noman and Georg developed a compound that blocks the action of RAR-alpha. They identified the best molecular structure with the help of a computer model.
“If we know what the keyhole looks like, we can make a better key; that’s where the computer model comes in,” Noman explained.
Its chemical compound, known as YCT529, is also designed to act specifically with the RAR-alpha receptor, and not other related receptors such as RAR-beta and RAR-gamma, in order to avoid possible side effects as much as possible.
When given orally to mice for four weeks, YCT529 dramatically reduced the animal’s sperm count and was 99% effective in preventing pregnancy with no observable adverse effects.
The mice regained fertility four to six weeks after stopping the drug.
The research team, which has received funding from the National Institutes of Health and the Male Contraception Initiative, is working with a company called YourChoice Therapeutics to begin human trials in the third or fourth quarter of 2022.
“I am optimistic that we will move forward quickly,” said Professor Gunda Georg, who believes her drug could be marketed within five years.
“There’s no guarantee it will work, but it would be really surprising if we didn’t see an effect in humans as well,” she added.
A lingering question about the future of male birth control pills is whether women will trust men to use them. Research shows that most women do trust their partners, and a significant number of men have expressed their willingness to take the drug.
“Male contraceptives will add to combined methods, offering new options that allow men and women to contribute in whatever way they see fit for their use,” added the nonprofit Male Contraception Initiative, which funds research and provides legal advice.