Phase 2 trials test a drug for both effectiveness and safety, typically in hundreds of volunteers, and look for harmful or unpleasant drug reactions. An earlier phase 2 trial of an injectable hormone-based male contraceptive was stopped in 2011 because the drug had too many side effects, including muscle pain, increased libido, acne and depression. Its development was supported by the World Health Organization and CONRAD, a nonprofit reproductive health organization.
For the gel trial, side effects may include weight gain and mood problems. “There will be a small percentage of men who will have some kind of side effect, but we know that’s also true of many different female contraceptives,” says Creinin. “We’re not looking for the product that will work perfectly for every man; we’re looking for the product that’s going to work very well for the most people.”
Next, the gel must be tested in a larger phase 3 clinical trial, which is likely to include thousands of couples. It would also need a drug company to manufacture and bring it to market, since the NIH and the Population Council do not have the ability to commercialize drugs. (NIH also sponsors early attempts of hormonal pills designed to lower sperm count by suppressing testosterone.)
Funding has been a major obstacle for male contraceptives: in recent years, pharmaceutical companies have not been involved in their research and development. Instead, philanthropic organizations and the public sector have been the main funders of such efforts.
But investment firms like Rhia Ventures, a San Francisco-based company focused on reproductive health, are trying to reverse that problem. CEO Erika Seth Davies says it’s important that non-hormonal forms of contraception are available to men. “In this post-Roe world, ensuring that there is a robust supply of contraception and access to contraception will be imperative,” she says. “We’re trying to make sure there are more options in the market because the responsibility for pregnancy prevention has been placed on women’s shoulders for so long.”
In addition to funding female contraceptive efforts, her company invests in Counter line, a Virginia-based biotech company developing a reversible, non-hormonal form of male contraception. Contraline’s method involves a permeable hydrogel injected into the vas deferens, the pair of tubes in the male reproductive system that transport sperm. The gel is designed to block sperm without affecting sensation or ejaculation. The company operates a small Phase 1 trial in Australia to test the safety of the approach.
Your choice Therapeutics and Eppin Pharma also pursues non-hormonal forms of male contraception. Your Choice is developing a pill designed to block sperm development, while Eppin’s method prevents sperm from fertilizing an egg. But these companies have not yet entered human testing.
One of the hurdles for all of these efforts will be getting regulatory approval for any product that passes Phase 3 trials. No male contraceptive has ever reached that stage where the US Food and Drug Administration will have to decide what level of risk is acceptable. Women’s birth control pills result in about one death per 200,000 users, primarily because of blood clots that can occur when using the pills. Men don’t have any of the physical risks of pregnancy, so the risk-benefit calculation will be difficult, Armory says. He believes this is one of the reasons pharmaceutical companies have been reluctant to get involved in male contraception. But in the end, more contraceptive options will benefit everyone, he says: “The market is huge – we’re talking about potentially millions of men.”
With the fall off Roe, Creinin believes it is time for the government to increase funding for research into male contraception. “We are on the precipice of changes in societal norms,” he says. “Whichever product is first to market, it will be a social game changer.”