The original study of hydroxyurea's effects, which was randomized, double-blind and tested for the placebo effect, took place between 1992 and 1995. In the new work, Martin H. Steinberg of the Boston University School of Medicine conducted a follow-up survey of 299 of these patients, who were given the option to continue, stop or start taking the drug. The team determined that among individuals who took the drug over a nine-year period there was a 40 percent reduction in deaths. "Hydroxyurea's ability to reduce complications in the sickest patients is strongly connected to lower death rates," notes study co-author Duane Bonds of the National Heart, Lung, and Blood Institute. "These results also confirm that the benefits of hydroxyurea persist. After the original trial ended, we didn't know if the benefits of the drug would be long term."
It is thought that the drug's beneficial effects stem from its ability to stimulate the production of so-called fetal hemoglobin. In people with sickle cell anemia, molecules of sickle hemoglobin clump together and form long rods that cause red blood cells to become rigid and take on a sickle shape. Increasing the level of fetal hemoglobin inside red blood cells helps to rein in this "sickling." In an accompanying editorial, Debra L. Weiner and Carlo Brugnara of Harvard Medical School call for increased use of hydroxyurea. They note that it "provides hope and help for improving quality of life and lifespan for patients with this devastating disease."