The Ongoing Search for Long-Acting, Reversible Male Contraceptives

May 9, 2017

Vasagel

by Elaine Lissner and Linda Brent

Access to safe, affordable, and effective birth control is critical to the health and well-being of women, and the good news is that nearly 65% of heterosexual couples around the world use some type of contraceptive. Yet a hefty percentage do not, and the lack of use of birth control, as well as birth control failures, lead to approximately 85 million unintended pregnancies each year. Unintended pregnancies account for 40 percent of all pregnancies worldwide. 

Most of the time, women take primary responsibility for birth control, and most methods are used by the woman. However, male methods such as condoms, withdrawal, and vasectomy, are used by 21 percent of couples worldwide. Because no one method is perfect, there is an ongoing need and desire for safe and effective birth control for men — especially for methods that don’t disrupt hormonal balance and allow for an easy return to fertility when desired. In most countries, at least half of men surveyed say they’d be willing to use new methods (and the passionate ones want a new method yesterday!).

While there is a high unmet need, no new male contraceptive has been approved for use in the last century. We regularly hear about scientific advances in altering male fertility; however, most new ideas don’t make it to market because of unacceptable side effects or lack of the multi-millions needed for development.

Yet several new methods look promising.

One of them is Vasalgel™, which is being developed by Parsemus Foundation as a long-acting, non-hormonal, reversible male contraceptive. Vasalgel is a polymer gel that is injected into the vas deferens – the tube that transports sperm – and works by blocking or filtering sperm.

Initial published studies in animals have been positive: Vasagel quickly blocks sperm in the semen as well as a vasectomy. Reversibility would make it revolutionary, and the ability to clear the material from the vas deferens and return sperm flow has been demonstrated in rabbits.

Parsemus Foundation has created a social venture company to develop Vasalgel and make it affordable and widely available. The foundation is reaching out to social investors to help fund its development. With a lot of men wanting to contribute to their relationship or have control of their reproduction, there’s hope! If all goes well, the first clinical studies in men will begin next year.

Vasalgel has a predecessor: a male contraceptive called RISUG that has been under development in India for over three decades. In fact, Parsemus Foundation originally bought the rights to RISUG in 2010, hoping to develop it outside India, but had to change formulations for acceptability to U.S. and European regulators.

While not much news has surfaced about RISUG’s development lately, a recent article indicated that clinical trials in 540 men have shown that it has worked for up to 13 years. The author reported that an application to regulators for approval of RISUG is expected to be made later this year. 

Two other reversible, non-hormonal male contraceptives deserve mention, one because it is made from a widely available plant and one because it could reduce the transmission of HIV:

  • Gandarusa (Justicia gendarussa) is made from an Indonesian plant and likely works by stopping the sperm’s ability to penetrate the egg. The product is in clinical trials in Indonesia and has worked well in men but is not yet being developed elsewhere.
  • The “clean sheets” pill works by relaxing some of the muscles in the vas deferens, which prevents the semen-carrying tubes from pushing the sperm forward, resulting in a dry orgasm. The method is still under development, but could have the added benefit of reducing the transmission of sexually transmitted infections like HIV that are carried in semen.

While developing a new male contraceptive takes years of research and development, there is reason for optimism that couples will have more options soon. Think it’s about time? For more information and to advocate for research on these and other up-and-coming male contraceptives, check out the Male Contraception Initiative.

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