Barriers to Treatment
The shift from broad-based methods of diagnosis and treatment to precise, individualized approaches could be slowed by several hurdles, most related to losing the economies of scale that come with treating large populations. Yet solutions are emerging.
Some analysts have speculated that, because most targeted therapies are aimed at a small slice of the population—Tarceva, for example, has been found most useful in only about one in 10 new cases of lung cancer—the pharmaceutical industry would never see an adequate return on the cost of development. “Five years ago, companies were generally resistant to developing drugs tailored for subsets of patients with a particular disease, fearing that would shrink profit margins,” says Edward Abrahams, executive director of the Personalized Medicine Coalition, a consortium of academic institutions, doctors, drug companies and others. “But now most have embraced pharmacogenetics. In the long run, it will save money because it’s very expensive for drug companies as well as patients to keep trying drugs that don’t work.”
The randomized controlled trial is designed to gauge effectiveness among large populations, while a drug such as Iressa may work well only for the small number of people with a particular genetic makeup. One way to get meaningful test results for targeted treatments would be to subclassify patients in a trial to determine who might or might not respond to a particular therapy. Profiling tumors as well as patients in clinical trials could also help. And in March 2005, in what many saw as a government endorsement of targeted therapies, the FDA released guidelines advising pharmaceutical companies to provide data from genetic tests that may be relevant to a drug’s usefulness.
Will only the wealthy be able to afford targeted therapies? “For an extremely expensive drug, the copay may be 20%, which is prohibitive for most people,” notes William J. Gradishar, director of breast oncology at Northwestern Memorial Hospital in Chicago. But that’s an issue that affects all kinds of treatments, and if targeted therapies ultimately save drug companies money, insurers and patients might see comparatively lower costs.