Pathways of innovation: a history of the first effective treatment for sickle cell anemia.

The promise of molecular medicine is the prevention and treatment of illness. Understanding the mechanism of the disease should allow one to "fix" it. For sickle cell anemia, however, knowledge of the biochemical basis of the disease was only partly responsible for finding a means of treating the disease--of equal value were hypotheses and conclusions generated from clinical observations. This article describes the research path that led to the first effective treatment for sickle cell anemia, hydroxy-urea. Rather than exemplifying the "bench-to-bedside" model commonly used to describe the process of therapeutic innovation, this history of this research reveals that the critical advances for the development of treatment came not from basic research, but instead from clinical and patient-oriented research. Given that the linear approach is the prevailing paradigm of therapeutic innovation, this history is important because it indicates the inadequacy of this approach for a relatively straightforward single-gene mutation disease such as sickle cell anemia and suggests the need for multiple models of innovation for more complex diseases. Thus, this article questions the expectations of molecular medicine and the dominance of a linear model of therapeutic innovation, which often excludes or subordinates other models of developing treatments.