Non-Hormonal Male Birth Control Pill With No Side Effects Smashes Early Trial

A non-hormonal, reversible male contraceptive pill with very few side effects might not be as far off as previously thought, early human trial results suggest.

In a first-in-human study, a drug called YCT-529, developed by YourChoice Therapeutics, was found to be safe and well-tolerated when administered to healthy men. Even at its highest dose, the oral pill had no effect on heart rate, testosterone levels, inflammatory biomarkers, levels of fertility-related hormones, sexual desire, or mood – plus no adverse events were reported.

Previous research in animals suggests that the drug is completely reversible six weeks after cessation, with no major side effects.

“These results warrant further clinical development of YCT-529,” the study authors write.

Currently, there are only two Food and Drug Administration approved male birth control options available: condoms and vasectomies. Scientists have been working away for decades in an attempt to create viable alternatives, but those that have reached the later stages of clinical trials have all been hormonal. This comes with a range of potential unpleasant side effects, meaning hormone-free options like YCT-529 are a much more appealing option.

YCT-529 works by blocking a protein called retinoic acid receptor alpha (RAR-α), which binds to retinoic acid (a derivative of vitamin A) and plays an important role in sperm development. In specifically targeting this pathway, the drug inhibits sperm production without causing any major side effects elsewhere.

In the trial, scientists administered a single dose of the drug to 16 healthy men aged between 32 and 59, all of whom had previously had vasectomies. Participants received varying doses, up to 180 milligrams, some on an empty stomach, and others after a meal. The pill was well tolerated and there was no obvious effect of food on its pharmacokinetics.

“Our first-in-human study reinforces YCT-529’s strong safety profile. It also shows ‘the Pill for men’ had no effect on sexual desire or mood,” lead author and YourChoice Therapeutics’ Chief Science Officer Dr Nadja Mannowetz said in a statement.

“[This] strengthens our ability to develop the first hormone-free birth control pill for men efficiently and as expeditiously as possible to meet the growing demand.”

The research is very much in its early stages – the next step is to progress to a Phase 2 trial to study safety and changes in sperm parameters – but it shows promise. Fortunately, such a trial is already underway in New Zealand.

When it comes to male contraception, “innovation is long overdue,” Akash Bakshi, CEO of YourChoice Therapeutics, stated. “Studies and surveys continue to show that men want to share the burden of pregnancy prevention with their partners,” making YCT-529 “potentially transformative for a healthcare segment that’s been stagnant for more than a century and a half.”

The results of the trial are published in Communications Medicine.