NONSTEROIDAL CONTRACEPTIVE

• Nonsteroidal contraceptive


  Contraceptive that does not contain steroid-based progesterone receptor (PR) agonists
• Oral contraceptives in current use

  • Contain steroid-based progesterone receptor (PR) agonists
  • Tend to interact with other receptors and pathways, leading to side effects that range from nausea, headaches, cramps, tenderness, and pain to mood changes and increased risk of cardiovascular complications
• Tanaproget


  A nonsteroid with high PR affinity and greater than 200-fold selectivity for PR over other steroid receptors, which could lead to an improved side-effect profile
• In a Phase I clinical study, Tanaproget was safe and well tolerated
• Tanaproget is now in Phase II trials
• Catherine M. Lynch, director of general obstetrics and gynecology at the University of South Florida College of Medicine, Tampa: 'The idea of a nonsteroidal contraceptive is very exciting. I will be very interested in what early data have to show and in the outcome of Phase III trials. If it is effective with few side effects, I think it could have a definite place in the contraceptive marketplace.'
• Tanaproget


  A heterocyclic compound with a cyano-N-methylpyrrole appended to an aryloxazinethione ring system
• As part of a structure-activity relationship study, the researchers obtained the first X-ray crystal structure of a nonsteroid bound to PR--work that helped us understand why the molecule is so potent and to design in additional selectivity