MODEL RELEASED. Anticancer drug design. Researcher using a computer to model the binding of an anticancer (chemotherapy) drug to an enzyme. Computer-aided design (CAD) of drug molecules allows researchers to study how the drug interacts with its target without actually making the drug. Improvements to the molecule's composition can be made quickly and easily on the computer, allowing the best possible drug to be decided on before any synthesis starts. Many anticancer drugs are enzyme inhibitors, and work by preventing the cancer cells from dividing.