versus 16 percent) (DiMasi et al., 2010). The proportion of orphan drug approvals accounted for by large pharmaceutical companies has grown in recent years (Tufts Center, 2010), but the committee found no analysis of the success rate specific to orphan drugs.
Given the relatively low odds of success and the high costs of drug development, pharmaceutical and biotechnology companies usually focus on potential therapies with the highest likelihood of generating a good financial return—as is the case with virtually all companies in any field. This has meant that potential therapies for rare diseases, including therapies for life-threatening conditions, have often languished in the early development pipeline. Moreover, conventional approaches to drug development are often not feasible for rare diseases, which offer not only small markets but also small populations for participation in clinical trials. To paraphrase the adage of Confucius, to achieve the goals of developing effective treatments for rare diseases calls for an adjustment of the action steps.
As described in Chapter 3, the Orphan Drug Act has provided incentives for the development of drugs for rare diseases, and the Food and Drug Administration (FDA) has approved more than 350 applications for