An elusive medical advance might finally be within grasp, one that could make some couples’ sex lives a lot more convenient. This week, researchers officially kicked off the first wide-scale clinical trial of a male contraceptive topical gel.
The trial, funded by the National Institute of Child Health and Human Development (NICHD), is set to enrol 420 relatively healthy and young couples. The couples will be recruited from nine different study sites in seven countries scattered across the globe, including Chile, England, and Sweden.
But the first batch of volunteers will come from sites in the US in Seattle, California, and Kansas.
The gel itself is a combination of the brand name drug Nestorone, which is a progestin hormone, and testosterone. While still relying on other contraceptives, male volunteers will apply the NES/T gel daily (to their arms and shoulders) for about 20 weeks. Once their sperm counts have plummeted to a point identified as infertility, they and their female partners will then be asked to only use the gel for pregnancy prevention for the next year.
After one year, they’ll stop taking the gel and be tracked for another six months to ensure that the effects on sperm count are reversible.
The basic premise of the gel is simple, according to Christina Wang, a researcher at the Los Angeles Biomedical Research Institute and principal investigator of the trial. Nestorone and other progestins are already regularly used in many female contraceptives, including the vaginal ring.
But when progestin is used alone in men, it both lowers their sperm count and causes testosterone levels to drop, which can lead to unwanted side effects like acne, weight gain, and a lowered sex drive. So the addition of testosterone is meant to counteract these effects while still leaving sperm counts incredibly low.
It hasn’t been smooth sailing for the development of the male contraceptive. There have been many promising, but ultimately failed candidates. And most recently, a clinical trial of a male contraceptive shot ran into stumbles concerning its safety risks, prompting researchers to shut the study down early in 2016.
That said, Wang and her colleagues have been working on and refining the gel for close to a decade, with small human studies dating back to 2009. And they believe they’ve managed to find the optimal balance between the two hormones to create a safe hormonal contraceptive.
“We’ve had over 200 men exposed to the medication, and we’ve never had any serious adverse events,” she told Gizmodo. “But we will be monitoring everything very closely.”
Aside from tracking the men’s sperm counts and physical health, Wang and others will also be keeping close tabs on how both sides of the couple are faring throughout the trial through periodic questionnaires — a step that’s a break from tradition, Wang says.
“This is something quite different from what we used to do. When you look at the studies of female contraceptives, they never assess the guys,” Wang said. “We want to make sure that the couple coming in, the couple that’s using this contraceptive, is satisfied with using this method.”
The existence of a male contraceptive would obviously take some of the burden off women to maintain a diligent contraception routine, but Wang points out there’s a real need for a better option for men looking to have safe and responsible sex, one that’s more convenient than an often irreversible surgical procedure like a vasectomy.
“Condoms are good and they protect you against sexually transmitted infections, but the failure rate of everyday use with condoms is very high,” she said, referencing research showing that 18 per cent of couples in the real world who exclusively use condoms still become pregnant within a year’s time. The gel, meanwhile, is expected to be as effective at preventing pregnancy as the many hormonal options available for women, 90 per cent or higher, depending on how well men follow dosing instructions.
It’ll take a while before you can expect this gel to become available in pharmacies, even if it does work as hoped. The trial will fully wrap up by 2022. And because it’s only a phase 2b clinical trial, it will still take more studies, involving thousands more men, before regulatory agencies like the Food and Drug Administration give it the stamp of approval.
Because this research is being sponsored by the US federal government, though, in conjunction with the Population Council, a nonprofit organisation that owns the right to Nestorone, Wang believes the eventual price tag for the NES/T gel wouldn’t be a barrier for couples who might be less able to pay for the treatment.
“If this works, and couples want to use it, it will not be restricted only to people who can afford it. That’s my understanding,” she said.
No word yet on whether the religious right will do as much to prevent men from accessing birth control as it does with female contraceptives.
[NIH]