Leukemia Drug Heralds Molecularly Targeted Era

Extract

When Brian Druker was a medical student, he envisioned destroying cancer without devastating the patient. “My most vivid memory was when we learned about chemotherapy. I thought, ‘My God, this stuff works but it's horrible.' ”

Nearly 20 years later, Druker the physician has helped a better way materialize in the form of STI-571, a drug that selectively targets chronic myelogenous leukemia cells without any of the traditional chemotherapy side effects. The darling of two recent scientific conferences, STI-571, which is owned by Novartis Pharmaceuticals Corp., East Hanover, N.J., passed phase I clinical testing with promising results and has entered phase II trials that will enroll several hundred patients in the United States and Europe.

If the drug continues to prove its worth against CML, which strikes 4,500 Americans annually, it will hit the market as one of the first representatives of a broad group of drugs called “ cytostatics.” Like monoclonal antibodies, another newer class of drug (the first, trastuzumab (Herceptin®) was approved in 1998), cytostatics are designed to home in on cancer cells without harming healthy ones; traditional chemotherapy agents, or “ cytotoxics,” kill dividing cells with little regard for whether they are cancerous.