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Compound stops sperm from swimming without side effects

A compound called EP055 binds to sperm proteins and significantly slows the overall motility of the sperm without affecting hormones.

The finding, which appear in PLOS ONE, suggest EP055 could be a candidate for contraceptive pill for men that’s free of side effects.

“Simply put, the compound turns-off the sperm’s ability to swim, significantly limiting fertilization capabilities,” says lead investigator Michael O’Rand, retired professor of cell biology and physiology in the University of North Carolina at Chapel Hill School of Medicine, and president/CEO of Eppin Pharma, Inc. “This makes EP055 an ideal candidate for non-hormonal male contraception.”

Currently, condoms and surgical vasectomy are the only safe forms of birth control currently available for men. There are hormonal drugs in clinical trials that target the production of sperm, but these affect the natural hormones in men much like female contraceptives affect hormones in women.

In 2001, O’Rand’s UNC School of Medicine lab published a paper in Gene about the discovery of the Eppin protein, which coats the entire sperm cell. They found this protein is crucial for the protection of the sperm. In 2009, O’Rand’s lab received an NIH grant to study compounds to inhibit the protein, and his team developed lead compounds that bound to Eppin.

When O’Rand retired in 2014 after 35 years, he formed Eppin Pharma Inc. with support from the UNC School of Medicine, Carolina Kickstart, and the North Carolina Biotechnology Center. The sole purpose of the company was to turn the compounds into a male contraceptive. He leased space — his old lab — and continued working on developing the lead compounds. Four years later, the company is on the cusp of developing an effective pill version of the lead compound, EP055.

During this most recent study, his team showed that thirty hours following a high-dose intravenous infusion of EP055 in male rhesus macaques at the Oregon National Primate Research Center at Oregon Health & Science University, researchers found no indication of normal sperm motility. Further, they observed no physical side effects.

“At 18 days post-infusion, all macaques showed signs of complete recovery, suggesting that the EP055 compound is indeed reversible,” says study co-investigator Mary Zelinski, research associate professor at the ONPRC at OHSU and associate professor of obstetrics and gynecology in the OHSU School of Medicine.

O’Rand and Zelinski indicate that more work is needed before EP055 becomes available for human use. Their teams have begun to develop a pill form of the compound and will eventually conduct a mating trial of EP055’s effectiveness against pregnancy.

The National Institutes of Health, Eppin Pharma Inc., and the North Carolina Biotechnology Center funded the study in part.

Source: Mark Derewicz for UNC Chapel Hill

Original Study DOI: 10.1371/journal.pone.0195953

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