Monoclonal Antibodies: A 25-Year Roller Coaster Ride

The discovery of hybridoma technology 25 years ago allowed researchers to isolate specifically defined monoclonal antibodies.¹ Enthusiasm soared as researchers envisioned in their hands the magic bullet against cancer. Then reality hit: Many obstacles stood in the path toward using monoclonal antibodies as standard therapy. With Food and Drug Administration approval of Herceptin for certain breast cancer tumors last fall and Rituxan for B-cell lymphomas in 1997, cancer researchers have regained their enthusiasm for this field, as witnessed by the 113 clinical trials in progress, 14 of them in Phase III.

Monoclonal antibodies (MAbs) are analogous to guided missiles homing in on a target. When a foreign invader such as a virus or bacterium enters the body, the immune system produces an array of specific proteins called antibodies. Each plasma cell in the body is responsible for producing one type of antibody only, which acts specifically against a particular...