Too many drugs? The clinical and economic value of incremental innovations

Drugs in the same therapeutic class differ in their therapeutic profile, metabolism, adverse effects, dosing schedules, delivery systems, and other features. In addition, such agents can provide backup if the initial drug sometimes fails in the development stage or in the market. The availability of a broad range of medicines enables physicians to treat with precision the individual needs of diverse patients and provides options when the first agent used is either ineffective or not tolerated. Some incremental innovations have been associated with overall cost savings. Competition among drugs in a therapeutic class drives prices down. Policies that limit research on incremental innovations may deny access to important therapies, reduce competition, and erode incentives for research.