FDA Giving Priority Review to Oxbryta in Treating Children, 4-11
The U.S. Food and Drug Administration (FDA) has agreed to consider Global Blood Therapeutics’ (GBT) request to expand the use of Oxbryta (voxelotor) to children as young as 4 with sickle cell disease (SCD).
The oral therapy is currently conditionally approved — when given at a daily dose of 1,500 mg — to treat SCD patients ages 12 and older.
In a separate application, also now under FDA review, the company is asking for approval of a weight-based, dispersible tablet form of Oxbryta that is grape-flavored and can be mixed with water or other drinks at room temperature for easier swallowing. This new 300 mg formulation provides similar benefits to the tablet form available to older patients, GBT reported, and allows for weight-based dosing in younger children.
The FDA granted priority review to both applications, effectively shortening the process from 10 to six months. A final decision is expected on or before Dec. 25.
“The FDA’s acceptance of our regulatory submissions for Oxbryta for the treatment of sickle cell disease in children ages 4 to 11 years and a pediatric-friendly dosage form of Oxbryta is an important step toward achieving GBT’s goal of bringing Oxbryta to all eligible patients suffering from this devastating disease,” Ted Love, MD, GBT’s president and CEO, said in a press release.
“There are few current therapeutic options for children under 12 years of age with sickle cell disease, which can cause irreversible multi-organ damage in the first few years of life,” he added.
Oxbryta is a first-in-class therapy designed to enhance hemoglobin’s ability to bind oxygen and thereby prevent the polymerization, or clumping, of hemoglobin within red blood cells — the phenomenon that ultimately leads to red blood cell sickling and destruction (hemolysis) in SCD. Of note, hemoglobin is the protein in red blood cells that is responsible for transporting oxygen.
The two applications were backed by data from the Phase 2 HOPE-KIDS 1 trial (NCT02850406), which is still enrolling up to 155 children and adolescents, ages 9 months to 17 years, with SCD at sites across the U.S. and in Lebanon and the U.K.
Findings in 45 children, ages 4–11, showed that six months of treatment with weight-based doses of Oxbryta resulted in rapid and sustained improvements in hemoglobin levels and reduced hemolysis markers.
These benefits were comparable to those seen in older patients treated with Oxbryta at its 1,500 mg dose in the now-completed Phase 3 HOPE trial (NCT03036813), which supported the therapy’s November 2019 approval in the U.S. for patients ages 12 and older.
As a condition for full (non-conditional) approval, GBT is evaluating Oxbryta in the HOPE-KIDS 2 trial (NCT04218084), a confirmatory Phase 3 trial designed to assess the therapy’s ability to lower stroke risk, as measured by a noninvasive ultrasound technique that uses sound waves to evaluate blood flow.
HOPE-KIDS 2 is enrolling an estimated 224 children and adolescents with SCD, ages 2–15, at sites worldwide. More information on study contacts and locations can be found here.
The European Medicines Agency (EMA) is currently reviewing an application seeking Oxbryta’s approval for SCD patients ages 12 and older in Europe.
Oxbryta was previously given breakthrough therapy, orphan drug, fast track, and rare pediatric disease designations by the FDA as a potential SCD treatment. In Europe, it was designated an orphan drug and priority medicine, and was named a promising innovative medicine in the U.K. All these designations help to expedite Oxbryta’s development and regulatory review.
“Given the profound unmet need, we appreciate the FDA prioritizing the review of potential treatments for the long-overlooked sickle cell disease community,” Love said.