A New Non-Hormonal Male Birth Control Pill Just Entered Human Trials

A drug candidate called YCT-529, which creator YourChoice Therapeutics is angling to make the first non-hormonal contraceptive pill for men, entered its Phase 1 clinical trial on December 13 in the U.K. This round will test the pill’s safety, tolerability, and oral dosage function in 16 participants.

This development is fundamental to contraceptive prospects. While an array of hormonal and non-hormonal options exist to make fertilization in a uterus nearly impossible, condoms and vasectomies are the only choices available for those assigned male at birth. Single-use condoms create waste and are prone to error, while vasectomies are considered permanent changes to the body. Contraceptives’ side effects can also change dramatically for everyone, so taking the burden off women would be a boon. While there have been clinical trials for hormonal male birth control options, including a topical gel that relies on testosterone suppression, the logistics of gaining approval for more advanced stages of testing slows progress.

YCT-529’s contraceptive mechanism hinges on inhibiting a protein — retinoic acid receptor-alpha (RAR-alpha) — that’s crucial to metabolizing vitamin A in testicles. In other words, it locally blocks vitamin A production, which helps produce and release sperm. However, this vitamin A-blocker doesn’t come anywhere close to creating a general deficiency. It only works in the testicles, and in previous animal studies has been observed to fully reverse 14 weeks after stopping usage. This long buffer period also means that missing one or two pills wouldn’t create a high risk of pregnancy.

This inhibitor also makes it non-hormonal, meaning it doesn’t act directly on reproductive organs or hormone production. Rather, it’s meant to temporarily meddle with vitamin production in a way that has an effect on sperm production, diminishing the possibility of egg fertilization.

Akash Bakshi, co-founder and CEO of YourChoice Therapeutics, told STAT that limited side effects are expected based on prior studies in animals. In a mouse study, YCT-529 was 99 percent effective in preventing pregnancy. The same mice that received the contraceptive were able to father pups normally four to six weeks later.

“We believe this will be more attractive to men, most of whom view pregnancy prevention as a shared responsibility even despite today’s limited contraceptive options, which are permanent or only moderately effective,” Bakshi told Clinical Trials Arena.