Alternative Name: Epididymal Peptidase Inhibitor

Description: Eppin is a sperm surface protein that binds semenogelin (SEMG1) and is critical for the protection of sperm from the enzymatic degradation of the semen coagulum, which frees the spermatozoa for motility and capacitation. Eppin is the contraceptive target for a small organic compound that binds Eppin and inhibits sperm motility. Blocking Eppin has been also shown to inhibit the motility required for fertilization by decreasing the sperm pH and reducing calcium levels.

Product Details

Reference target/product: EP055

Status Details

Began discovery in: 2009

Status Details:
  • Contraceptive efficacy has been shown in a non-human primate model. Anti-Eppin antibodies from male monkeys have been shown to inhibit human sperm motility (in vitro).
  • High throughput screening has been conducted to identify compounds that bind to Eppin and cause inhibition of sperm motility, similar to the effects of anti-Eppin antibodies. Lead compounds are currently being tested for PK and toxicology.

Additional Information

  • Eppin Pharma website: https://eppinpharmainc.com/

  • Silva EJR, Hamil KG, et al. (2012) Characterization of EPPIN's semenogelin I binding site: A contraceptive drug target. Biol Repro 87(3):56, 1-8.

  • O'Rand MG, Widgren EE, et al. (2006) Eppin: an effective target for male contraception. Mol Cell Endocrinol 250:157-162.

  • O'Rand MG, Hamil K, Adevai T, Zelinski M. (2018). Inhibition of sperm motility in male macaques with EP055, a potential non-hormonal male contraceptive​. PLoS ONE 13(4): e0195953.

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