Soluble adenylyl cyclase (sAC) is a protein that plays an essential role in the acquisition and regulation of the fertilising capacity of mammalian spermatozoa. This study describes the effects of TDI-11861, a selective inhibitor of sAC, and its usefulness as a male contraceptive, administered orally in a single dose prior to sexual intercourse, without affecting ejaculation or sexual behaviour.   

What is interesting about this study is that the drug targets a very specific sperm enzyme (one of the isoforms, ADCY10, is almost exclusively expressed in sperm cells) and, although other isoforms are more widely distributed, I think they have hit the nail on the head. 

Other attempts have been made to develop male contraceptives, but so far none of these drugs have made it into the clinic. Although this research has been carried out in mice and clinical trials are needed to corroborate the efficacy of the drug in humans, this study opens the door to the development of the first single-use male contraceptive pill, offering an interesting alternative to the exclusive use of oral contraceptives in women.