New Delhi: Igniting hopes of a breakthrough that, for the first time globally, promises to make the responsibility of family planning more equitable, an oral contraceptive pill for men has now moved to efficacy trials in humans after demonstrating safety in early-stage trials.
The drug, named YCT-529, is a first-in-class, orally administered, non-hormonal male contraceptive developed by scientists in the United States. It works by halting sperm production.
A promising feature of the drug is that it stops interfering with sperm production within weeks of ceasing the treatment.
A study published in the scientific journal Nature Communications last month showed the drug to be 99 percent effective in preclinical studies. More advanced studies—whose results are yet to be made public—have confirmed its safety for use in men during early human trials, paving the way for efficacy trials on a larger group of men, for which recruitment has now commenced.
The early-stage phase 2 trial in New Zealand is expected to yield results within the coming months, as the drug’s effects are expected to become evident within weeks of administration.
While more than 15 contraceptive options are available to women globally—including oral and emergency contraceptive pills, intrauterine devices, and surgical alternatives—men currently only have two options: condoms and vasectomy.
Vasectomy is a surgical contraceptive method that involves cutting and sealing the vas deferens, the tubes that carry sperm from the testicles. It is a permanent method of birth control, whose reversal is possible but not always guaranteed.
Scientists working on developing YCT-529 said that a male contraceptive pill would expand the range of contraceptive options available to couples and offer a more equitable approach to contraception.
“Male contraception is an unmet medical need. Men have few options to control their fertility—condoms, which can have significant failure rates, and vasectomy, which is difficult to reverse,” Gunda Georg, the lead scientist whose lab at the University of Minnesota in the US, in collaboration with researchers from Columbia University, has developed the drug, told ThePrint.
She added that the drug, which has been licensed to YourChoice Therapeutics, a San Francisco-based company, has already been tested on a few men in the UK as part of a phase 1 trial, which has now concluded.
Those working in the area of women’s reproductive health in India said that if the drug proves successful, it could be a turning point.
“An oral contraceptive pill for men can indeed be a game-changer—even though, given the male reproductive system, developing one is a difficult proposition,” Chandrashekhar V. S., India director at Americares, a global non-profit organisation focused on health and development, told ThePrint.
At present, the only short-term contraceptive available to men is the condom. Any additional options would help reduce the burden of contraception, which currently falls almost entirely on women, he said.
Gender rights activist Debanjana Choudhuri also highlighted that the responsibility of contraception continues to fall disproportionately on women, with male contribution—due to socio-cultural norms—being practically negligible.
“There is, therefore, a need for options like oral contraceptive pills for men, as they will broaden and improve the basket of choice. There should be concerted efforts to make such choices and information widely accessible,” she told ThePrint.
Why hopes are high
It is estimated that nearly half of all pregnancies in the US and globally are unintended. Researchers have emphasised the urgent need for additional contraceptive options that can be used throughout the reproductive lifespan of both men and women.
“Women have multiple contraceptive options, but men are limited to condoms and vasectomy,” researchers observed, noting that although testosterone and its derivatives have been clinically evaluated for male contraception, none have reached the market.
YCT-529 functions by interfering with the vitamin A signalling pathway, which is essential for sperm production and fertility.
The research has so far focused on the drug’s effectiveness, safety, and reversibility. YCT-529 works by blocking the RAR alpha acid receptor, which is involved in sperm production. Preclinical trials were conducted on male mice and macaque monkeys.
As part of the research, mice received daily doses of 10 or 20 milligrams per kilogram for either two or four weeks, while the monkeys were gradually administered increasing doses of up to 7.5 milligrams per kilogram per day.
Scientists then analysed sperm count, mating fertility, testicular biopsies, histological examinations, and hormone levels—including testosterone, follicle-stimulating hormone (FSH), and inhibin B—all of which play significant roles in male fertility.
The results showed that among mice that received 10 milligrams per kilogram for four weeks, the contraceptive success rate was 99 percent, and in monkeys, sperm counts dropped sharply within just two weeks.
Importantly, fertility was fully restored within 6–12 weeks in mice and 73–148 days in monkeys upon discontinuation of the treatment, and no serious side effects were reported.
Furthermore, in animal studies, hormone levels remained stable, and no permanent damage to testicular tissue was detected, which supported continued evaluation of the drug in human trials. A phase 1 trial involving eight healthy men, completed last year, showed the drug to be safe.
As part of the phase 2 trial, the study population will include healthy men who have opted for a vasectomy and are awaiting the procedure, as well as men who, in the investigator’s opinion, have made a firm decision not to father children in the future.
“I think the world is ready for an orally administered male contraceptive. Recent surveys have shown that many men would take such a drug if it were available,” Georg said.
(Edited by Radifah Kabir)