Biomarkers measure drug-induced changes in a patient's blood or tissue. Such changes can confirm drug activity and thereby help select patients more likely to respond to treatment. These biochemicals are revolutionizing cancer drug development.
It's a revolution sorely needed. A recent
After 20 years of study, we have begun to see clinical benefits for patients from drugs that were designed to exploit cancer gene-based targets. These drugs cannot be optimally developed using approaches designed for the more traditional cytotoxic chemotherapies: Maximum tolerated dose may not indicate optimal dose; dose-limiting toxicity may not be proliferation-linked; and myelosuppression side effects cannot be used as surrogate markers of cytotoxicity, as many of...