Hydroxyurea for sickle cell disease effective in infants, study finds


Hydroxyurea, the cancer drug long used for treating sickle cell disease in adults and adolescents, is just as effective and safe for treating the disease in infants under the age of 19 months, according to a major new study to be published Saturday. The new findings suggest that physicians should begin using the drug in infants as soon as they begin showing signs of the disease.

“There are now strong reasons for healthcare professionals to consider starting children who have sickle cell disease as early as possible with hydroxyurea,” said Dr. Susan B. Shurin, acting director of the National Heart, Lung and Blood Institute, which sponsored the six-year study.

Sickle cell anemia is an inherited blood disorder in which a genetic defect in hemoglobin -- the oxygen-carrying component of red blood cells -- causes the cells to become deformed into a sickled shape. The cells tend to become tangled, blocking small blood vessels and causing episodes of intense pain. The blockages ultimately damage organs such as the kidney and spleen and can lead to strokes and premature death. An estimated 100,000 Americans, primarily African Americans, have the disorder.


Infants are protected in the first six months or so of life by the presence of fetal hemoglobin, which does not cause sickling. But production of fetal hemoglobin fades with age. Hydroxyurea, which is now increasingly called hydroxycarbamide, stimulates the production of fetal hemoglobin, easing symptoms of the disorder. It is widely used in adults, but it has not been clear whether it is safe in younger children. Many patients also receive transfusions of unaffected blood to reduce their symptoms. The only cure is a bone marrow transplant to give the patient healthy bone marrow cells that do not produce the mutant hemoglobin.

For the new study, dubbed the Pediatric Hydroxyurea Phase III Clinical Trial, or Baby Hug, a team led by Dr. Winfred Wang of St. Jude Children’s Research Hospital in Memphis enrolled 193 infants and toddlers, ages 8 to 19 months, at 14 U.S. sites. Half received daily hydroxyurea and half a placebo. The team reported in the journal Lancet that children receiving the drug showed improvements in kidney and spleen function. The drug recipients had half as many pain episodes, 177 events among the 62 who completed the trial versus 375 among the 75 who received placebo. Recipients also had fewer episodes of dactylitis, which is a pain in the hands and feet accompanied by swelling, fewer hospitalizations and fewer episodes of acute chest syndrome, a pneumonia-like infection that can be life threatening. The researchers will continue monitoring the children until their teen years to ensure there are no long-term complications.

“Hydroxyurea offers an excellent treatment option to improve the lives of infants and potentially all persons with sickle cell anemia,” Wang concluded.