Children’s Research Hospital
Doctor examines sickle cell patient Photo from St. Jude
The US Food and Drug Administration (FDA) has approved a hydroxyurea product (Addmedica’s Siklos) for use in pediatric patients with sickle cell anemia.
Siklos is intended to reduce the frequency of painful crises and the need for blood transfusions in pediatric patients age 2 and older who have sickle cell anemia and recurrent moderate to severe painful crises.
The recommended dose of Siklos is 20 mg/kg once daily.
The FDA granted priority review and orphan drug designation to the application for Siklos.
The agency’s approval of Siklos was based on data from the ESCORT HU study (NCT02516579). The trial was an evaluation of Siklos in 405 patients, ages 2 to 18, with sickle cell disease (SCD).
Thirty-five percent of these patients (n=141) had not received hydroxyurea prior to study enrollment and were therefore evaluable for efficacy. The median follow-up was 23 months (range, 12 to 80 months).
The researchers found that Siklos prompted an increase in fetal hemoglobin. Median fetal hemoglobin percentages were 5.6% (range, 1.3 to 15.0) at baseline and 12.8% (range, 2.1 to 37.2) at around 6 months after Siklos initiation (the value closest to 6 months collected between 5 and 14 months).
In addition, the percentage of patients with at least 1 vaso-occlusive episode, 1 episode of acute chest syndrome, 1 hospitalization due to SCD, or 1 blood transfusion decreased after 12 months of Siklos treatment.
The proportion of patients with at least 1 vaso-occlusive episode was 69.2% at baseline and 42.5% at 12 months. The proportion with at least 1 episode of acute chest syndrome was 23.6% and 5.7%, respectively.
The proportion with at least 1 hospitalization due to SCD was 75.5% and 41.8%, respectively. And the proportion with at least 1 blood transfusion was 45.9% and 23.0%, respectively.
The most common adverse events (occurring in at least 10% of patients) were infections (39.8%), gastrointestinal disorders (13.1%), neutropenia (12.6%), nervous system disorders (11.1%), and metabolic and nutrition disorders (10.9%).
Full prescribing information for Siklos is available on the FDA website.
