Adult sickle cell drug hydroxyurea proves effective in young children

A drug used for the treatment of sickle cell anemia in adults has now been shown to cause significant improvements in very young children with the disorder.

The finding is an important one as these young patients are especially vulnerable to serious organ failure and even death at an early age. The study results will be published in the October 1, 2005, issue of Blood, the official journal of the American Society of Hematology.

Sickle cell anemia is a genetic blood disorder that can cause severe pain, fatigue, and organ damage to the kidneys, spleen, and liver. It occurs in about one in every 500 African-Americans. In the new study, 21 children from two to four years old who had sickle cell anemia were given the drug hydroxyurea orally as a flavored liquid formula. A majority of the children took the drug for at least four years and more than half of the participants completed all six years of the study.

The treatment was well-tolerated in the patients, with only one child's dosage permanently reduced during the study due to adverse effects. The drug's primary function, to counteract the effects of the disease by increasing and sustaining fetal hemoglobin production, was achieved in all study participants. Patients treated with hydroxyurea also weighed more and were taller than untreated children with the disorder – their growth rates were even comparable to those of normal children.

Another measure of success of the therapy was that the study patients had improved spleen function, an important finding as many children with sickle cell anemia lose spleen function by two years of age. Participants also experienced significantly fewer incidents of acute chest syndrome, a potentially life-threatening disorder associated with sickle cell disease. During the study, one four-year-old girl died of sepsis, a toxic bacterial infection, though no increased risk of sepsis was found among the hydroxyurea-treated patients.

"This study demonstrates that hydroxyurea is an efficient and safe treatment option for young children with sickle cell anemia," said Jane Hankins, M.D., M.S., of St. Jude Comprehensive Sickle Cell Center and lead study author. "As sickle cell anemia is a chronic disorder, having a drug that can be started early and continued long-term with few adverse effects is of significant importance to the way we treat this debilitating disease."