Aragon
Pharmaceuticals Inc. is developing small molecules that it hopes will
be more potent than other second-generation hormone receptor antagonists in the
clinic, and last week began a Phase I/II trial of its lead ARN-509 to treat
castration-resistant prostate cancer. The company also is working on
third-generation molecules that go one step further by programming the
receptors for proteasomal degradation.
Drugs that antagonize hormone
receptors directly in their hormone binding domains have been around for years
and are effective for treating patients at early stages of the disease. "But
tumors are smart and evolve to become resistant within three to five years so
that a patient will no longer respond to the hormonal therapy," according
to President and CEO Richard Heyman.