A contraceptive pill to stop sperm by preventing pregnancies in preclinical models is currently being developed, according to a report by Weill Cornell Medicine. 

The drug undergoing experiment would demonstrate that “an on-demand male contraceptive” is possible. Jochen Buck and Lonny Levin, professors of pharmacology at Weill Cornell Medicine, said in a February 14. 

According to Messrs Buck and Levin, condoms have been options for men, following their existence for about 2,000 years. 

“Research on male oral contraceptives has stalled, partly because potential contraceptives for men must clear a much higher bar for safety and side effects,” Mr Levin noted in the study, adding, “Because men don’t bear the risks associated with carrying a pregnancy. The field assumes men will have a low tolerance for potential contraceptive side effects.” 

If the drug development and clinical trials are successful, Mr Levin hopes to walk into a pharmacy one day and hear a man request “the male pill.”    

The team discovered that mice genetically engineered to lack sAC are infertile.

In 2018, Melanie Balbach, a postdoctoral associate in Messrs Buck and Levin’s lab, made an exciting discovery while working on sAC inhibitors as a possible treatment for an eye condition. 

Ms Balbach found that mice given a drug that inactivates sAC produce sperm that cannot propel themselves forward. According to her, sAC inhibition might be a safe contraceptive option for men who lacked the gene encoding sAC and were infertile.

She noted that the new “Nature Communications” study demonstrated that a single dose of an sAC inhibitor called TDI-11861 immobilizes mice sperm for up to two and half hours while the effects persist in the female reproductive tract after mating. 

“After three hours, some sperm begin regaining motility; by 24 hours, nearly all sperm have recovered normal movement. Our inhibitor works within 30 minutes to an hour and every other experimental hormonal or nonhormonal male contraceptive takes weeks to bring sperm count down or render them unable to fertilize eggs,” Ms Balbach explained. 

She added that it takes weeks to reverse the effects of other hormonal and nonhormonal male contraceptives in development. 

She also observed that since sAC inhibitors wear off within hours, “men would take it only when, and as often as needed.” 

The next step for the team is repeating their experiments in a different preclinical model. 

These experiments would lay the groundwork for human clinical trials that would test the effect of sAC inhibition on sperm motility in healthy human males.