Results of a preclinical study have shown that a new compound can immobilise sperm temporarily without side effects. The drug, currently known as EP055, binds to sperm proteins to significantly slow their overall mobility.
EP055 does this without affecting hormones, and therefore holds the potential to become a male contraceptive pill without any side effects.
“Simply put, the compound turns off the sperm’s ability to swim, significantly limiting fertilization capabilities,” said lead investigator Michael O’Rand. “This makes EP055 an ideal candidate for non-hormonal male contraception.”
Keeping hormones in check
Condoms and surgical vasectomy are the only safe forms of birth control currently available for men, but it is hoped that safe and reversible drugs will become available within a decade.
Other potential male contraceptives target the production of sperm. However, these affect the natural hormones in men in a similar manner to female contraceptives in women, which are associated with a range of side effects including mood changes, weight gain, headaches, nausea and changes in libido.
In 2016 a male contraceptive injection was found to be effective, but a high rate of side effects – including acne, mood disorders and reduced sperm count after treatment – led to the trial being withdrawn early.
Trial results and future
During the EP055 study, male rhesus macaques, a type of monkey, were given a high dose of the drug intravenously.
Thirty hours after the dose, researchers observed no indication of normal sperm motility and additionally, no physical side effects were observed.
In observations and measurements made 18 days after the infusion, all macaques showed signs of complete recovery, suggesting that EP055 is reversible.
More work is required before EP055 becomes available for human use, with the next stages of development involving the testing of a pill form of the compound, and a mating trial to determine EP055’s effectiveness against pregnancy.