Weill Cornell Medicine researchers devised a drug temporarily immobilizes spermthus preventing pregnancy. Here the bad: so far, they have only tested it in mice. But if they manage to turn the finding into a treatment for humans, which is still a distant goal, it will mean that men could take a pill and enjoy a few hours, even a whole weekend without worries.
Think of something like Viagra, but for birth control.
That would be an important step in a field that has received very little innovation. For a long time, men have only had two options: condoms or a vasectomy. That leaves women most of the burden when it comes to preventing pregnancy. And that burden has grown heavier as more states ban abortion and make some forms of birth control more difficult to access.
For decades, male contraceptive research has focused on limiting sperm production. That is a difficult task. Every day, men produce tens of millions of sperm; to prevent a pregnancy, a drug needs to reduce that number to less than 1 million.
Hormones like testosterone can do that, but they have many drawbacks. Because it takes about 60 days for sperm to fully develop, a hormonal drug given today will not prevent a pregnancy the same day, or even the next day; I would avoid it in two months. And reversing the effects of the drug is also a two month process. Hormone therapies also carry side effects such as mood swings, acne, or weight gain. which can be counterproductive in the long run. (The female birth control pill can have similar drawbacks, as well as a risk of blood clots, all the more reason to invest in other approaches.)
Newer approaches, including the one taken by Weill Cornell’s team, take a different tack: stop sperm from swimming. But to get to where sperm are produced (in the testicles), a drug must be delivered throughout the body. That creates many opportunities for unpleasant or even dangerous side effects.
Announced statements suggest that it is possible. The drug blocks a protein called soluble adenyl cyclase (or, as the researchers call it, “sAC”) that is essential for sperm motility. Under the microscope lens, swimmers appear to be floating, the tail of each sperm no longer wagging furiously. The effect began within 30 minutes of taking the drug and appeared more than two hours. In the study, none of the mice that received the drug got their partners pregnant in that period, while the mice that didn’t get the drug got 30% of their partners pregnant.
There are, of course, the usual precautions for preliminary data. For example, researchers still need to do more testing on the drug to make it suitable for humans, refining properties like how long the effect lasts in the body.
Even with the caveats, researchers who have spent their careers working on male contraceptives are enthusiastic about the data. “This is great!” said John Amory, a researcher at the University of Washington School of Medicine who is leading a study of one of the most advanced male contraceptives, a hormonal gel, after reviewing the Weill Cornell article. “When will we test it in men?”
It won’t be soon. But the Weill Cornell researchers are confident enough to have founded a company, Sacyl Pharmaceuticals. Their next steps will be testing their compounds in rabbits, which are apparently a good benchmark for human reproduction, and working to find a drug with better properties, for example, one that takes effect just as quickly, but works for a day or two. instead of a few hours.
The problem is that even if science does, the chance of men taking birth control pills is long term.
One barrier is the lack of funding. The big pharmaceutical companies had always paid little attention to the field and, over the years, abandoned it entirely. Currently, the National Institutes of Health (NIH) and the Bill & Melinda Gates Foundation foots the bill for nearly all early-stage studies of male contraceptives. But government and philanthropic funding can only get a project done so far. While there have been little signs of industry life in the broader field of reproductive health, much more momentum is needed for there to be any hope of male contraceptives reaching the market.
Another challenge, likely keeping the industry on the sidelines, is the still murky regulatory path for these drugs. Researchers aren’t sure what the Food and Drug Administration (FDA) will need to see to be convinced that their treatments are effective. When considering approval of new contraceptives for women, the agency typically asks companies to collect data on 20,000 menstrual cycles. “But if that same metric makes sense for a male contraceptive, which tends to be tested by recruiting people in committed relationships and recording whether or not a couple gets pregnant, the data becomes uncertain,” said Daniel S. Johnston, Branch chief. NIH Center for Contraception Research.
Also it will be necessary to demonstrate that a male contraceptive is safe, something that will be difficult for male contraceptives because of the way regulators balance the risks and benefits of new drugs. For women’s methods of birth control, regulators compare the risks of a contraceptive with those of a pregnancy. Compared to giving birth to a child, the side effects of hormone pills or an IUD are relatively small.
But men are not the ones who get pregnant. So if creating an unwanted pregnancy is deemed by regulators to be “risk free” for men, even minor side effects may require too much risk. Men’s health researchers say that threshold needs to be reconsidered. “There is a degree of double standards that limits the approval of a male contraceptive,” says Bobby Najari, director of male infertility at New York University School of Medicine.
“Many men are prescribed Viagra and Cialis so they can have sex, and these drugs have side effects.but they disappear, and the user decides if they’re worth it,” says Amory, the scientist working on the male contraceptive gel.
But perhaps the most fundamental concern for the field is: if male contraceptives do finally come to market, will men actually take them? There is at least some good news on that front. The limited data available probably does.
In a study conducted on behalf of the Gates Foundation and the Male Contraceptive Initiative and presented last year to the World Health Organization (WHO), approximately 39% of the 3,000 men surveyed said they would try a male contraceptive within the first year. it was available, while 78% would give it a chance in the first five years of being on the market. The survey also measured women’s attitudes and found high levels of trust in their partners as family planners.
The results also suggest that men would appreciate having a range of options — the way women can between, say, a daily pill, a monthly vaginal ring, or a years-old intrauterine device.
Getting to the point where men and their female partners will have a range of options would be a welcome change. Now we just need the drug companies to stay out of it.
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