A new approach to chemotherapy

Current FDA-approved CYP inhibitors nearly all exhibit significant off-target effects, inhibiting other CYPs besides the desired one.  This is particularly dangerous when the major drug metabolizer in the liver, CYP3A4, is unintentionally inhibited.   CYP3A4 breaks down foreign substances, including many of the drugs used in chemotherapy.   Chemotherapy drugs are usually toxic to all dividing cells, but because cancer cells divide in an uncontrolled fashion, the toxicity is primarily aimed at the cancer.   However, if those drugs are not broken down, they will attack normal cells as well.   That's why you often hear the phrase "Don't take with strong CYP3A4 inhibitors" in drug commercials.    

Unlike most FDA-approved CYP inhibitors, the CYPselect inhibitor requires a very precise fit into the CYP active site in order to bind tightly.  "If it doesn't fit, it won't inhibit".    We design our molecules so that they very closely resemble the natural substrate of the CYP, and structural studies show that our inhibitor of CYP17A1 (target for prostate cancer therapy) binds in almost precisely the same way as the natural substrate for this enzyme.