Birth control may no longer be solely reliant on the woman. There has been a big development towards expanding the birth control options for men. A team of scientists has developed a male oral birth control pill that was 99 percent effective in mice and didn't cause observable side effects. The drug is expected to enter human trials by the end of this year, according to the scientists.
They will also present the findings at the American Chemical Society's spring meeting.
Researchers have been invested in finding a male equivalent to the female birth control pill since it was first approved in the 1960s, Md Abdullah Al Noman, a graduate student at the University of Minnesota who will present the work says.
Sharing the responsibility
"Multiple studies showed that men are interested in sharing the responsibility of birth control with their partners," he says. Prior to this, males had two effective options: condoms or vasectomies. The latter is often expensive and not always 100 percent successful.
The efforts to develop a male equivalent involved targeting the male sex hormone testosterone. However, it caused severe side effects such as weight gain, depression, and increased levels of a cholesterol known as low-density lipoprotein, which increases heart disease risks.
Although the female pill also carries side effects such as blood-clotting risks, the calculation risk is different because women face becoming pregnant without contraception.
RELATED: The 411 On The New Male Birth Control Pill
Developing a non-hormonal drug
With hopes of developing a non-hormonal drug, Noman, who works in the lab of Professor Gunda Georg, targeted a protein called "retinoic acid receptor (RAR) alpha."
Our bodies convert vitamin A into different forms, including retinoic acid, a principal ingredient in any wrinkle-banishing super serum. Retinoic acid plays important roles in cell growth, sperm formation, and embryo development. In the body, retinoic acid binds to a group of retinoic acid receptors to encourage sperm to mature and function properly.
In order to perform these functions, retinoic acid needs to interact with RAR-alpha. Lab experiments have shown mice without the gene that creates RAR-alpha are sterile. So, Noman and Georg developed a compound that blocks the action of RAR-alpha. The best molecular structure was identified with the help of a computer model.
"If we know what the keyhole looks like, then we can make a better key -- that's where the computational model comes in," Noman adds.
After several years of research and constructing over 100 potential drug candidates, the University of Minnesota researchers struck gold witha compound they called YCT529. The compound was also designed to interact specifically with RAR-alpha, and not two other related receptors RAR-beta and RAR-gamma, in order to minimize potential side effects.
What the results show in mice
YCT529 drastically reduced sperm counts and was 99 percent effective in preventing pregnancy in a mating trial with mice, which is on track with the effectiveness of the female birth control pill. The pill was administered orally to mice for four weeks.
Researchers monitored weight, appetite and overall activity and found no apparent adverse impacts, which indicates that humans may also be able to tolerate the drug well. However, mice can't report side effects like headaches or mood changes.
Four to six weeks after being taken off the drug, the infertility in the mice was able to be reversed and the mice were back to fathering pups. This opens the door for a male birth control pill that is well tolerated.
What's next?
The drug still has to run through clinical trials before it can officially hit the market, but this could be the best hope yet for a male birth control pill.
The team has received funding from the National Institutes of Health and the Male Contraceptive Initiative and is working with a company called YourChoice Therapeutics to start human trials by the third or fourth quarter of 2022 or next year, Georg shares.
“YCT529 is the furthest ahead of all contraceptive agents for men,” Georg, a medicinal chemist at UM who led the new study, told The Daily Beast. “We’re really excited about it and we were able to license it to a company, YourChoice Therapeutics.”
"I'm optimistic this will move forward quickly," she says, envisioning a possible timeline to market in five years or under. "There is no guarantee that it will work...but I would really be surprised if we didn't see an effect in humans as well," she adds.
One question that has often surrounded the conversation around male contraceptive pills is whether or not women will trust men to use them.
However, surveys have shown that most women have faith in their partners to use them responsibly. Additionally, a significant number of men have indicated that they are open to the medication.
"Male contraceptives will add to the method mix, providing new options that allow men and women to contribute in whatever way they deem appropriate to contraceptive use," argues the nonprofit Male Contraceptive Initiative, which engages in fundraising and advocacy.
The new findings could also open the door for other non-hormonal birth control drugs that operate in other ways, such as slowing down sperm movement, according to Georg and Al Norman. They say the important thing is to make safe options that encourage men to take birth control while removing the reproductive burden from women.
“Birth control is a critical health-care issue,” Al Noman concludes. “Because about more than half of all pregnancies in the U.S. are unintended pregnancies. And that can lead to very poor outcomes, whether in terms of the child’s health or maternal health and also financial and career advancement of women. We need to have more investment in the research and development of the male birth control pill.”
