An estimated 90,000 to 100,000 Americans are affected each year by sickle cell disease (SCD), a serious disorder that causes normal red blood cells to become rigid and form in a crescent ?sickle? shape.[1] The abnormal shape of these cells causes them to clump together and become embedded in the blood vessels of organs, causing pain, infection, potential organ damage, and stroke. Even with advancements in drug therapies and prevention methods, safe and effective treatment options remain limited.

Research assessing the safety and efficacy of hydroxyurea therapy in pediatric patients with sickle cell disease (SCD) was resented at the 53rd Annual Meeting of the American Society of Hematology in San Diego, CA. ?Studies presented [at the annual meeting] underscore the need to assess the quality and effectiveness of therapy for sickle cell disease, particularly in the pediatric population,? said Susan B. Shurin, MD, Acting Director of the National Heart, Lung, and Blood Institute (NHLBI) in Bethesda, MD.

Significant improvement
Shurin, who has been instrumental in the U.S. Department of Health and Human Services? (HHS) recent initiative to promote research advances in SCD, stated, ?I am hopeful that discoveries like these, combined with continuing efforts to develop new treatments, share public health data, and provide evidence-based guidelines, will soon lead to significant improvement in the lives of patients with SCD.?

Hydroxyurea is the only federally approved therapy to prevent sickle cell complications in adults with sickle cell anemia (SCA). However, based on positive results from previous trials assessing clinical benefits for use in children, specialists are increasingly considering the use of hydroxyurea in their pediatric patients. Results from the BABY HUG Follow-up Study I suggest that continued use of hydroxyurea is both safe and effective in infants with SCA.

Hydroxyurea in very young patients
The Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG) was a multicenter, randomized clinical trial that assessed the clinical benefits of hydroxyurea in very young patients with SCA. Results from the study demonstrated that hydroxyurea administered to infants with SCA provided substantial clinical benefit over placebo.

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Randomized treatment
Researchers launched the BABY HUG Follow-Up Study I in 2008 to assess the safety and efficacy of continued treatment with hydroxyurea in infants with SCA. The Follow-Up Study I included 163 children between the ages of 28 and 44 months who had participated in the BABY HUG trial and who had completed at least 18 months of randomized treatment of either hydroxyurea or placebo. Investigators collected clinical and laboratory data every six months from patient medical records, including use and dosage of hydroxyurea, blood counts, clinical imaging, and frequency of sickle cell-related complications.

High acceptance rate
At Follow-Up Study entry, families enrolling their children did not know their child?s randomized study treatment assignment in BABY HUG; 82%initially chose clinical prescription of open-label hydroxyurea, demonstrating a high acceptance rate for the drug. Through the 36 months of follow-up, acceptance remained high, with 68 to 75% of the participating families reporting that their children continued to take hydroxyurea.

Clinical benefits

Follow-Up Study I data indicate that children who continue to take hydroxyurea have statistically lower rates of pain crises requiring emergency room visits and hospital admissions for any reason when compared to those taking placebo. These clinical benefits are similar to those demonstrated by the drug in BABY HUG, the results of which were published earlier this year and are consistent with previously published trials that detail the therapy?s benefits in older children and adults.

Understanding the benefits
?Our study data reveal not only that the clinical benefits of hydroxyurea continue with ongoing administration, but also the wide acceptance of the treatment by the families of our patients, demonstrated by the high percentage of families that continued their children on hydroxyurea after the randomized trial ended,? said lead author Zora R. Rogers, MD, Professor of Pediatrics at UT Southwestern Medical Center Dallas and Clinical Director of the Bone Marrow Failure and General Hematology Program at Children?s Medical Center Dallas. ?Analysis of growth and development assessments obtained in the Follow-Up Study along with these clinical results will further enhance our understanding of the benefits of the use of starting hydroxyurea in children with sickle cell disease at a very young age.?

The BABY HUG Follow-Up Study I is funded by the National Heart, Lung, and Blood Institute (NHLBI) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).

Rogers will present this study in an oral presentation.

For more information:
Program: Oral and Poster Abstracts
Type: Oral
Session: 111. Hemoglobinopathies, excluding Thalassemia: Sickle Cell Disease – Therapeutic Interventions
Abstract: 7 Hydroxyurea Treatmentof Young Children with Sickle Cell Anemia: Safety and Efficacy of Continued Treatment — the BABY HUG Follow-up Study
When: Sunday, December 11, 2011: 4:30 PM
Where: Elizabeth Ballroom AB (Manchester Grand Hyatt San Diego).

Clinical trials:
Hydroxyurea to Prevent Organ Damage in Children With Sickle Cell Anemia (Completed)
Long-Term Effects of Hydroxyurea in Children With Sickle Cell Anemia (The BABY HUG Follow-up Study)
Transcranial Doppler (TCD) With Transfusions Changing to Hydroxyurea (TWiTCH).

Also read:
First Patient Enrolled in Phase II Clinical Studyof HQK-1001 in Patients With Sickle Cell Disease
Hydroxyurea Shown to be Safe and Effective for Infants and Toddlers with Sickle Cell Anemia.
– Hydroxyurea Therapy in Infants with Sickle Cell Anemia Does not Cause Long-term Genetic Damage.

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