Latest news with #NadjaMannowetz
Mint
4 days ago
- Health
- Mint
Male contraceptive YCT-529 a breakthrough? Birth control pill that temporarily halts sperm without hormones clears trial
In a new development, men may soon be able to equitably share the responsibility of avoiding pregnancy along with their partners as YCT-529, a birth control experimental pill has passed its initial human safety test, making another way for contraception. It will reportedly cease sperms temporarily without hinderance to hormones. Unlike conventional hormonal birth control pills, the innovative pill developed by YourChoice Therapeutics temporarily halts sperm production while leaving testosterone levels unchanged, New York Post reported. It functions by inhibiting a protein named retinoic acid receptor alpha, which is essential in the sperm creation process. Initial studies indicate that its effects are completely reversible. In tests involving male mice, YCT-529 significantly decreased sperm production, leading to reversible infertility after only four weeks of treatment. When these treated males bred with females, the drug demonstrated a 99% success rate in preventing pregnancy. Comparable outcomes were observed in male nonhuman primates, with sperm counts declining within two weeks of beginning the treatment. Importantly, fertility was fully restored in both species once the drug was discontinued. Mice recovered within six weeks, while primates regained fertility between 10 and 15 weeks. No side effects were noted in either group throughout the studies, the report added. The initial human trial of the medication included 16 healthy males aged 32 to 59, all of whom had previously had vasectomies, a surgical operation that severs and blocks the tubes transporting sperm from the testicles to prevent conception. This additional safety measure was required because no nonhormonal male contraceptive had ever been evaluated in humans before. Scientists wanted to eliminate any chance of permanently impacting fertility, in case participants wished to have children later, Nadja Mannowetz, co-founder and chief science officer of YourChoice Therapeutics, informed Scientific American. She clarified the objective was not to assess effectiveness but to determine if the drug was tolerated well and to observe how it accumulated in the body. Researchers tested multiple doses and found no concerning side effects. There were no changes in heart rate, hormone levels, inflammation, sexual function, or mood. This finding is important because hormonal contraceptives have previously been linked to side effects like mood swings, decreased libido, weight gain, and acne. Mannowetz pointed out that across all doses, the drug demonstrated good and rapid bioavailability, which means it remained active in the body without breaking down too quickly, the report mentioned.
New York Post
4 days ago
- Health
- New York Post
Birth control pill for men that temporarily stops sperm — without hormones — passes safety trial
Men might finally get a chance to bench their swimmers. A first-of-its-kind male birth control pill just cleared its first human safety test, raising hopes that it could soon open the door to a new era of contraception. The drug, YCT-529, is currently enrolled in a larger clinical trial, with experts hoping it'll be ready to hit the shelves by the end of the decade. Here's everything you need to know about this potential pregnancy game-changer. Advertisement 4 The development comes as condom use among men is declining. TanyaJoy – What is YCT-529? Unlike traditional birth control pills that disrupt hormones, this experimental pill from YourChoice Therapeutics temporarily halts sperm production without affecting testosterone levels. It works by blocking a protein called retinoic acid receptor alpha, which plays a key role in the sperm making process. The best part: Early evidence suggests it's totally reversible. Advertisement Does the pill work? In tests on male mice, YCT-529 sharply reduced sperm production, causing reversible infertility within just four weeks. When treated males mated with females, the drug proved 99% effective at preventing pregnancy. Similar results were seen in male non-human primates, whose sperm counts dropped within two weeks of starting treatment. Advertisement 4 If approved, the pill could provide men with more control over their reproductive health. Christoph Burgstedt – Notably, both animals fully regained fertility after stopping the drug, with mice recovering within six weeks and primates within 10 to 15 weeks. No side effects were reported in either group. Is it safe for humans? Advertisement So far, so good. The first human trial testing the drug involved 16 healthy men between 32 and 59 — all of whom had previously undergone vasectomies, a surgical procedure that cuts and blocks the tubes that carry sperm from the testicles to prevent pregnancy. This extra precaution was necessary because no non-hormonal male contraceptive had ever been tested in humans before. Researchers wanted to avoid any risk of permanently affecting fertility, just in case participants wanted to father children later, Nadja Mannowetz, co-founder and chief science officer of YourChoice Therapeutics, told Scientific American. The goal wasn't to test effectiveness but to see if the drug was well tolerated and to measure how it built up in the body, she explained. 4 The contraceptive had no major side effects when tested in male animals and humans. InsideCreativeHouse – After testing multiple doses, researchers didn't find any concerning side effects, including no changes in heart rate, hormone levels, inflammation, sexual function or mood. That's notable, because hormonal contraceptives have previously been linked to side effects like mood swings, libido loss, weight gain and acne. Advertisement Across all doses, scientists also 'saw good and quick bioavailability,' meaning the drug stayed active in the body without breaking down too fast, Mannowetz noted. Why do we need a male birth control pill? 'Studies and surveys continue to show that men want to share the burden of pregnancy prevention with their partners,' Akash Bakshi, CEO of YourChoice Therapeutics, said in a statement. 'But they have just one non-permanent contraceptive option — condoms — and it's 170 years old.' Across the country, the rate of unintentional pregnancy is nearly 50%. While female contraception offers a variety of options — including pills, implants, injections and devices — vasectomies remain the only reversible male birth control method approved by federal regulators. 4 Currently, women bear the majority of the burden for contraception. luckybusiness – Advertisement However, the success of vasectomy reversal procedures varies widely from person to person, and the longer the time since the procedure, the lower the success rate tends to be. While condoms are available, studies show that men are increasingly not using them. Several promising reversible male birth control candidates are currently in development and undergoing clinical trials, but most rely on hormonal methods, which carry a higher risk of side effects. Advertisement 'A safe and effective male pill will provide more options to couples for birth control,' Gunda Georg, chemist and pharmacist at the University of Minnesota, which is collaborating on the drug with YourChoice Therapeutics, said earlier this year. 'It will allow a more equitable sharing of responsibility for family planning and provide reproductive autonomy for men,' he continued. What's next for YCT-529? The drug is now being tested in a larger trial with over 50 men who either had vasectomies or made the decision to opt out of fatherhood. Advertisement Participants will take the pill daily for 28 and 90 days at different doses, while researchers monitor safety and see how well it shuts down sperm production. The trial is expected to wrap up by mid-2026 — and if all goes well, the first male birth control pill could be just a few years away from hitting the medicine cabinet.
Yahoo
6 days ago
- Health
- Yahoo
YourChoice Therapeutics announces second Nature publication
Peer-reviewed paper summarizes safety profile for hormone-free male birth control pill SAN FRANCISCO, July 22, 2025--(BUSINESS WIRE)--YourChoice Therapeutics, Inc., pioneering hormone-free family planning products, today announced that Communications Medicine, a Nature Portfolio Journal, published the results of YCT-529's first-in-human study, which showed that single doses of the hormone-free birth control pill for men were well tolerated. YCT-529 is a retinoic acid receptor-alpha (RAR-α) antagonist designed to be a first-in-class, hormone-free, orally administered male contraceptive. Positive results from the phase 1a study supported the candidate's current trial, which reinforces YCT-529 as the only non-hormonal birth control pill for men being evaluated in human studies. The manuscript, "Safety and Pharmacokinetics of the Non-Hormonal Male Contraceptive YCT-529," showed that a single dose (up to 180 mg) of YCT-529 was well-tolerated in 16 male volunteers. Further, it had no effect on participants' heart rate, blood parameters, testosterone levels, sexual desire or mood. The publication follows a March 2025 publication describing YCT-529's preclinical studies, which showed it was 99 percent effective, 100 percent reversible within six weeks after cessation, and had no side effects in mice and non-human primates. The current clinical study is investigating multiple ascending doses (MAD) of the once-daily pill in up to 50 male volunteers to evaluate safety, tolerability and effect on sperm count. Lead author and YourChoice Therapeutics' Chief Science Officer Nadja Mannowetz, PhD, commented: "A peer-reviewed publication for 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. Two back-to-back publications demonstrate our commitment to conducting rigorous studies, which 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." Nearly half of all pregnancies globally are unintended, suggesting an urgent need for more male contraceptive options. There is also high demand for new methods. A recent study showed men are very interested in using new male contraceptive options and women are confident they'll take them correctly. YCT-529 is on track to be a novel option. It blocks sperm production by disrupting vitamin A metabolism in the testes. It specifically inhibits retinoic acid from binding to its receptor, RAR-α, a pathway essential for sperm development and supported by nearly a century of research. "Studies and surveys continue to show that men want to share the burden of pregnancy prevention with their partners," said Akash Bakshi, CEO of YourChoice Therapeutics. "But they have just one non-permanent contraceptive option—condoms—and it's 170 years old. Innovation is long overdue. Data show men favor an oral contraceptive and one that's hormone-free, positioning YCT-529 as potentially transformative for a healthcare segment that's been stagnant for more than a century and a half." UK-based Quotient Sciences conducted the phase 1a study, which began in December 2023 and was completed in June 2024. New Zealand-based NZCR is conducting the current study. About YCT-529YCT-529, a first-in-class new chemical entity, is a retinoic acid receptor-alpha (RAR-α) inhibitor that is designed to prevent production of sperm cells in the testes as well as their release. YourChoice Therapeutics is currently assessing safety and efficacy of YCT-529 in a phase 1b/2a clinical trial in New Zealand as the first non-hormonal, oral male contraceptive. YourChoice Therapeutics developed YCT-529 in collaboration with Dr. Gunda Georg, a globally recognized medicinal chemist and awardee of one of the largest NIH-funded Contraceptive Centers. The Male Contraceptive Initiative (MCI) has been committed to funding the early research and YCT-529's phase one clinical trial in men. About YourChoice TherapeuticsYourChoice Therapeutics is a clinical-stage biopharmaceutical company developing the first hormone-free birth control pill for men. Based in San Francisco, the company is advancing the only male pill in human studies. Preclinical studies showed YCT-529 performed as effectively or better than the female birth control pill, and a phase 1a study demonstrated that YCT-529 was well tolerated by men. Future programs will apply the company's patented therapeutic platform to develop hormone-free family planning products for women. Established in 2018, the company received a $15M Series A investment in 2022. For more information, visit and follow the company on LinkedIn. View source version on Contacts Media:Shanti Skiffingtonshanti@ 617.921.0808 Sign in to access your portfolio
Scientific American
22-07-2025
- Health
- Scientific American
First Hormone-Free Male Birth Control Pill Shown Safe in Early Human Trial
When it comes to birth control, the market has long been skewed: female contraception comes in a variety of pills, implants, injections and devices, all approved by U.S. regulators. Condoms and vasectomies are the only male contraceptives available. Researchers have been chipping away at this problem for decades, and progress is finally ramping up. Now a male birth control pill with an entirely new kind of contraceptive mechanism has been tested for the first time in humans. In the first clinical trial of its kind, a nonhormonal oral contraceptive that reversibly stops sperm production has just been deemed safe for human use. The daily pill, called YCT-529, blocks a vitamin A metabolite from binding to its receptor in the testes; this prevents the chain of gene-expression changes that are required to start the sperm-making process. Safety results from the early phase 1 clinical trial were published on Tuesday in Communications Medicine. The trial did not assess the pill's efficacy in reducing sperm, and the drug's developer, YourChoice Therapeutics, is currently running trials to collect that data. But the safety finding is a crucial milestone, says Stephanie Page, an endocrinologist at the University of Washington School of Medicine, who wasn't involved in the study and has worked on other male hormonal contraceptives for more than 20 years. 'We really need more reversible contraceptive methods for men,' she says. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. The small trial included 16 healthy men aged 32 to 59, all of whom had undergone a vasectomy—a common surgery to prevent the release of sperm by snipping the vas deferens ducts in the scrotum. Enrolling only such participants was an extra precaution to avoid the risk of permanently affecting participants' fertility; no one has clinically trialed a nonhormonal male contraceptive pill before, says Nadja Mannowetz, co-founder and chief science officer of YourChoice Therapeutics, who oversaw the new trial. Using nonfertile participants worked for the trial because the team wasn't yet evaluating the drug's effectiveness but rather its tolerability and bioavailability (active levels that build up in the body), Mannowetz says. Participants were split into two groups. In the first, people either received an initial dose of 10 milligrams (mg) of YCT-529 and then a second, 30-mg dose two weeks later or got a placebo each time. Participants in the second cohort either received a first dose of 90 mg and then a second dose of 180 mg two weeks later or always received a placebo. All participants took the pills after fasting. Four from each cohort were selected to return and take a third, 30-mg dose after a high-fat, high-calorie breakfast to see whether food might affect the drug's tolerability. Across dosages 'we saw good and quick bioavailability,' meaning the drug didn't rapidly break down in the body, Mannowetz says. On average, it took two to three days for the drug availability levels in the blood to reduce by half—a promising result that suggests the pill might only be needed once daily if it later proves effective at reducing sperm. Mannowetz anticipates the final dosage that will hit stores if the drug is eventually approved by the U.S. Food and Drug Administration will probably be closer to the higher amount tested, 180 mg, though follow-up trials will help discern the exact optimal dose. The research team didn't note any adverse side effects related to the drug. An advantage of a nonhormonal contraceptive medication is that, in theory, there's a smaller chance of certain side effects such as changes to sexual function, libido or mood, Mannowetz says. The results are exciting and important, Page says—but she points out that this was just one small trial. 'I think it would be overstating the data to say they know much about side effects yet,' she says. ' Every medication on the market has side effects.' Several other reversible male birth control methods are now in the clinical trial pipeline as well. The furthest along is NES/T, a combination of the progestin Nestorone and testosterone. Applied daily as a gel to the shoulders and upper arms, it is absorbed into the bloodstream through the skin. Like the YCT-529 pill, the gel targets sperm production, but it does so by circulating testosterone and progestin—hormones that tell the brain to halt the production process. Researchers have just completed a larger, longer phase 2 clinical trial of NES/T to show effectiveness and will hopefully start a phase 3 trial soon, says Page, who has been involved in the gel's clinical research. Users of a male contraceptive that targeted sperm production, such as NES/T or YCT-529, would need to take it for about three months daily before it would take effect because that's how long it takes the body to produce mature sperm cells. Sperm production would resume about three months after a user stopped taking the medication. A couple of other candidates for hormonally acting daily male contraceptive pills are in early development. A hydrogel implant called ADAM is also being tested in early clinical trials. ADAM acts as a reversible vasectomy, physically blocking off the vas deferens to prevent sperm release until the implant is removed. And studies show growing interest. One paper published in 2023 found that 75 percent of more than 2,000 men surveyed in the U.S. and Canada were willing to try novel contraceptives. And a report in 2019 found nearly 50 percent of U.S. men aged 18 to 49 who had sex with women, did not have a vascectomy or beliefs that prevented the use of contraception and did not wish to parent a pregnancy were 'very interested.' These stats line up with Page's experience in the field: 'Men are very eager to have more reproductive agency and to participate in contraception,' she says, and all these contraceptives in the pipeline could elevate individuals' and couples' agency over their sexual and reproductive lifestyles.
