A fast-acting male contraceptive pill has passed initial tests

He condom and the vasectomy are methods male contraceptives. There are also other methods under development in scientific laboratories. One of them manages to momentarily halt the advance of the sperm.

If women have the morning after pill, in the future men will be able to have access to the male contraceptive “the next hour””. The development for the time being worked in a survey with animals in the UNITED STATES.

It is a contraceptive developed by researchers at Weill Cornell Medicine. It has been successful in stopping sperm and preventing pregnancy in preclinical models. The study, published in the journal Nature Communication, demonstrates that an à la carte male contraceptive is possible.

It was 100% effective in preventing pregnancy within the first two hours of administration. Its effectiveness dropped to 91% within the first three hours.

According co-authors of the study, doctors Jochen Buck and Lonny Levinprofessors of pharmacology at Weill Cornell Medicine, the discovery could be a game-changer for contraception. Because they remembered that condoms, which have been around for about 2,000 years, and vasectomy were the only options for men until now.

Research on male oral contraceptives was stagnating. Indeed, potential male contraceptives must meet a much higher standard for safety and side effects, Levin explained.

He explained that since men do not run the risks associated with pregnancy, it is assumed that will have a low tolerance possible side effects of contraceptives. The researchers did not initially seek to find a male contraceptive. They were friends and colleagues with complementary knowledge. But Levin challenged Buck to isolate a cell signaling protein called adenyl cyclase (AC), also known as adenylate cyclase, which had long eluded biochemists.

Buck couldn’t resist. It took him two years. Buck and Levin then focus their research on the study of proteins and join their laboratories. The team found that mice genetically engineered to lack adenyl cyclase are sterile.

Then, in 2018, Dr. Melanie Balbacha postdoctoral associate in his lab, made an exciting discovery while working on inhibitors of the protein as a potential treatment for an eye condition.

He discovered that mice given a drug that inactivates the protein produce sperm unable to propel themselves forward. Another team’s report that men lacking the gene encoding AC protein were infertile but healthy reassured the team that inhibition could be a safe contraceptive option.

The new study by Nature Communication shows that a single dose of a protein inhibitor, called TDI-11861, immobilizes sperm in mice for up to two and a half hours and that the effects persist in the female reproductive tract after mating.

At three o’clock, some sperm begin to regain their mobility; at 24 hours, almost all sperm have regained normal movement.

Male mice treated with TDI-11861 mated with female mice showed normal mating behavior, but failed to fertilize females despite 52 different mating attempts. In contrast, male mice treated with an inactive control substance fertilized almost one-third of their female partners.

“Our inhibitor works within 30 minutes to an hourBalbach clarified. “All other experimental hormonal or non-hormonal male contraceptives take weeks to reduce sperm count or render them unable to fertilize eggs,” he added.

Additionally, Balbach noted that it takes weeks to reverse the effects of other hormonal and non-hormonal male contraceptives in development. He said that since protein inhibitors wear off within hours and men took them only when and as often as needed to make day-to-day decisions about their fertility.

Drs Balbach and Levin noted that the development of TDI-11861 required extensive medicinal chemistry work, conducted in collaboration with the Tri-Institutional Therapeutic Discovery Institute (TDI). TDI works with researchers from Weill Cornell Medicine, Memorial Sloan Kettering Cancer Center and Rockefeller University to accelerate early-stage drug discovery.

“The team is already working to make the protein’s inhibitors more suitable for use in humans,” Levin said. Doctors Buck and Levin created Sacyl Pharmaceuticals with their colleague, Dr. Gregory Kopf, who is the scientific director of the company.

The team’s next step is redo your experiences in a different preclinical model. These experiments would lay the groundwork for human clinical trials that would test the effect of protein inhibition on sperm motility in healthy men, according to Dr. Buck.

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

“For 50 years, different methods of male contraception have been studied. One type of method is hormonal: they inhibit sperm production. The others are non-hormonal: they have the advantage of not having the side effects associated with the use of hormones. The method described in the work published in NatureCommunications it belongs to the non-hormonal group and is based on the inhibition of a protein called “soluble adenylate cyclase” present in the sperm”, explained to GlobeLiveMedia Patricia Cuasnicú, Conicet principal researcher at the Institute of Experimental Biology and Medicine (IBYME ) . .

The protein is involved in both the development of motility during the process of “maturation” of sperm that occurs in the epididymis in the male, and in the development of a very vigorous motility called “hyperactivity”. ascend through the female tract while undergoing the “training” process.

The protein inhibitor they developed in the United States “would interfere with the development of sperm motility in both pathways, and can be used as a male or female contraceptive,” Dr Cuasnicú said.

“Since its effect lasts for a few hours, the idea is that the contraceptive is only used when needed. That is why it is considered an ‘on demand’ or ‘pericoital’ contraceptive. It would have the advantage of not bringing side effects precisely because of its transient and not chronic use”, he explained.

In addition, Cuasnicú pointed out, “researchers suggest that it could be used by both members of the couple at the same time to increase its effectiveness and to have both members of the couple involved, which is why they also refer to this method as a couple’s contraceptive.

Although this is an interesting and promising result, believes the scientist, “it is important to specify that the studies carried out to date have only been carried out on mouse models. It remains to be analyzed whether an inhibitor of this type works in humans without producing side effects”.

Susan Walker, a contraception expert at Britain’s Anglia Ruskin University who is not involved in the research, was also “a bit skeptical” that the pill could ever be marketed as many other initiatives have failed. . But the “striking advantage” of almost immediate effectiveness offered “the possibility of seeing a sexual partner take a pill”, he acknowledged.

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