The promise of targeted therapy: cancer drugs become more specific.

Toxic chemotherapeutic agents are slowly being supplemented by a new generation of drugs that recognize specific targets in or on cancer cells. Although these molecular and genetic approaches are in their infancy, they hold the promise of more effective therapies with markedly fewer side effects. Several targeted agents are already approved by the US Food and Drug Administration (FDA) for use in malignancies, and numerous others are in clinical trials.