Thursday, researchers from Harvard and Baylor Universities announced they have created a molecule that could lead to a reversible male birth control pill.
The molecule works by moving from the bloodstream into the testicles, where it can bind to BRDT, a protein that's integral to sperm production. Once bound, the cells "forget" how to make mature sperm. In live mouse trials, after a few weeks off the drug, male mice became fertile again, and their offspring didn't suffer from any obvious birth defects. The only noticeable side effects were "mild weight loss," according to James Bradner, the Harvard University scientists involved with the study.
In lab tests, the molecule appeared to bind well to human BRDT, suggesting that the technique could work in humans.
Researchers have been looking for a good, temporary male birth control solution for decades, but drugs that don't cause severe side effects have proved elusive. Martin Matzuk, a developmental biologist with the Baylor College of Medicine and co-author of the report, has been among those leading the charge. U.S. News & World Report spoke with him about why his latest research is so exciting.
It seems like we hear every couple of months that there's a new male birth control treatment on the way—what makes this one different?
I think the main thing about this study is we're targeting the male germ line [cells that develop into sperm], so it's a non-hormonal contraceptive that's reversible, too. There are drugs that can wipe out the entire germ line, but you want a drug that will be reversible. The exciting thing about it is, if you target a specific protein, you'll have less chance of side effects.
You've been doing this for a long time and you've seen a lot of potential drugs come through the pipeline—would you say this is one of the most promising?
I think it is one of the most promising things I've seen. As we begin article, 1-in-25 genes in mammals is expressed in the male germ line, so I think there are many targets out there. We're working on finding other targets in the laboratory.
As you've said—you're working on other potential male birth control solutions. Is there a good reason to not put all your eggs in this basket and focus on multiple solutions?
My feeling is that there may be multiple drugs that we'll develop in parallel. Men may have a number of alternatives. It's better than having only one option—if you look at high blood pressure and other types of diseases, certain people have side effects with a certain drug. You want to have multiple drugs coming in. There are drugs being developed, not only for men, but this could also could be used in female reproductive tract as a vaginal gel, it could alter the ability of sperm to get to the ova.
So with these things it's always hard to say, but everyone will want to know when this will be available. If things go according to plan, what kind of timeline are we looking at?
My hope is within the next 10 years, there will be a drug on the market for men. Groups are already working on testosterone options, but there are side effect issues with them. Long term trials will need to be done on any drug, but I think that, really, before the end of the decade, we'll actually see something coming out. I can't say it'll be this one, but we have grant funding now to continue working on the project. There have been some pharmaceutical studies that have gone from having a target [like we do] to having FDA approval within six years. I don't see any reason why this can't be one of them.
So how would this likely be delivered? Are you envisioning a pill, something delivered with a vaccine? Something topical? How often would they have to be taken?
I think having daily injections would not be a good strategy. I think, depending on efficacy of drug, having a slow release, similar to how some female birth control works, or having a pill, that would be the best option. And if the drug is binding to the sperm, a vaginal jelly is an alternative.