Oxbryta Shows Promise in Reducing Cell Sickling in Pediatric SCD Patients
In a promising leap forward for pediatric sickle cell disease (SCD) treatment, the oral medication Oxbryta (voxelotor) has been shown to reduce the sickling and disintegration of red blood cells in children, which could enhance oxygen delivery throughout the body.
These findings come from a subgroup analysis within HOPE-KIDS 1 (NCT02850406), an active Phase 2a study assessing Oxbryta’s safety and efficacy. The study entitled, “Voxelotor improves red blood cell functionality in children with sickle cell anaemia: An ancillary study of the HOPE-KIDS 1 trial,” recently featured as a brief communication in eJHaem journal, sheds new light on the potential benefits of this treatment.
Global Blood Therapeutics, recently acquired by Pfizer, developed Oxbryta—currently authorized in the United States for SCD in patients as young as four years old, and for those over 12 years old in the European Union, UK, and select Middle Eastern nations. The drug functions by boosting haemoglobin’s oxygen retention, averting the formation of stiff chains that spur cell deformation—yielding better haemoglobin counts and curtailing haemolysis.
Teams from Emory Children’s Center in Atlanta along with Pfizer embarked on a mission to unravel how Oxbryta enhances red blood cell functionality, concentrating on their deformability—a crucial trait enabling cells to navigate narrow capillaries effortlessly.
Focusing on ten paediatric SCD patients aged between four and eleven enrolled in HOPE-KIDS 1, who underwent 48 weeks of daily weight-based dosed treatment with Oxbryta, notable findings emerged. At baseline, these children had below-normal haemoglobin levels spanning 76 to 100 grams per litre (g/L). By week 24 of therapy, 70% showed a haemoglobin increase over 10 g/L with 60% surpassing the 100 g/L threshold. Moreover, signs of haemolysis saw a decline starting from week 12.
These “improvements may lead to prolonged sickle [red blood cell] survival and oxygen delivery to tissues,” the researchers wrote. However, as deformability “is highest in the early years of life, these findings may not be generalizable to adults with SCD,” they wrote.
Source: Chonat, S., Fields, E., Baratz, H., Watt, A., Pochron, M., Dixon, S., Tonda, M., Brown, C. and Archer, D., 2024. Voxelotor improves red blood cell functionality in children with sickle cell anaemia: An ancillary study of the HOPE‐KIDS 1 trial. Ejhaem.
