News Release

Study shows hydroxyurea as a viable option for some children who have sickle cell anemia

A sickle cell anemia study has found that the drug hydroxyurea is as effective as blood transfusions in children to reduce blood flow velocities in the brain, which is a key risk factor for stroke. The findings appear in The Lancet and were presented at the annual meeting of the American Society of Hematology.

Some children living with sickle cell anemia are at increased risk of stroke. The degree of risk is measured using a technique called Transcranial Doppler, which can determine the velocity of blood in the brain. Children who have high Transcranial Doppler velocity measurements have increased risk for stroke.

The current standard of care for children with sickle cell anemia who are at high risk of stroke is regular blood transfusions. The National Institutes of Health-supported study sought to answer whether daily administration of hydroxyurea was no worse than blood transfusions as a means of lowering the velocity of blood flow. 

The Transcranial Doppler with Transfusions Changing to Hydroxyurea (TWiTCH) study was stopped early due to the early achievement of positive results in November 2014. Hydroxyurea is the only drug approved by the Food and Drug Administration to treat sickle cell anemia.

Researchers supported by the NIH’s National Heart, Lung, and Blood Institute (NHLBI) studied 121 children and divided them into two groups: one that received transfusions and one that was transitioned from transfusions to daily doses of hydroxyurea.  

“We wanted to provide the medical community with another way to help treat children who are at the greatest risk of stroke,” said Russell Ware, MD, Ph.D., one of the study’s principal investigators at Cincinnati Children’s Hospital Medical Center in Ohio. “While blood transfusions are an effective option, there are questions about the long-term consequences of regular transfusions. Now families and healthcare providers have an additional treatment option with hydroxyurea.”

Part of the challenge is that children who receive regular blood transfusions must also be managed to avoid the danger of iron overload. Chelation, or iron-reduction, therapy is needed for those receiving transfusions.

Researchers from 26 sites recruited children ranging in age from 4 to 16 years old. Those who participated in the TWiTCH study received treatment for a two-year period. The study authors indicated that the findings suggest that hydroxyurea could be effective at reducing risk of stroke, though this was not a primary goal of the study.

“No child should ever have to face the prospect of suffering through a stroke,” said Gary H. Gibbons, MD, director of the NHLBI. “Our vision is that NHLBI’s research efforts will realize a stroke-free generation of children living with sickle cell anemia. Studies like this are vital for moving us toward this worthwhile goal.”

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