ATLANTA (January 31, 2020) – A new drug targeting the underlying cause of sickle cell disease (SCD) and tested at Children’s Healthcare of Atlanta was recently approved by the FDA for patients ages 12 and older. The treatment increases hemoglobin levels in red blood cells, which is associated with improved quality of life. Known in its generic form as voxelotor, it is the first and only FDA-approved drug in a new class of therapy for SCD that slows the sickling process.
“It is possible that voxelotor may change the course of sickle cell disease,” said Clark Brown, M.D., Ph.D., clinical director of Children’s Sickle Cell Disease Program at the Aflac Cancer and Blood Disorders Center and lead investigator for the trial at Children’s.
SCD is a lifelong, inherited blood disorder affecting 100,000 people in the U.S. One in 13 African American babies is born with the sickle cell trait due to its origins in sub-Saharan Africa. SCD causes the hemoglobin protein in red blood cells to become sickled, deoxygenated and rigid during a process known as polymerization. This results in anemia that reduces healthy red blood cells used to deliver oxygen to the body.
Voxelotor, also known by the brand name Oxbryta™, works by inhibiting or slowing the polymerization process and increasing hemoglobin’s ability to carry oxygen. It is an oral therapy taken once-a-day and the first in a new class of drugs which operate by this mechanism, targeting sickle cell disease at its source.
“The increase in hemoglobin means red blood cells are carrying more oxygen to organs and tissues throughout the body,” said Brown who is also an associate professor of pediatrics at Emory University School of Medicine. “We've seen fewer complications, less severe anemia and less fatigue.”
Symptoms of SCD may include fatigue, swelling of the hands and feet, jaundice and severe episodes of pain called pain crises. Complications include stroke, permanent organ damage, infections and delayed growth. Blood and marrow transplant, or BMT, is the only cure for SCD, but not all patients are medically eligible for it. Voxelotor helps provide an alternative for those patients and those for whom current medications are ineffective.
“Patients sometimes experience severe side effects from the treatments currently available, which may cause them to stop taking their medication,” said Brown. “With voxelotor they can attend their jobs and school more regularly, because the SCD is more controlled. The hope is that since the medication has very few side effects, patients will only need to be seen once every three months, instead of once a month.”
The HOPE (Hemoglobin Oxygen Affinity Modulation to Inhibit HbS PolymErization) Study was published in The New England Journal of Medicine. The phase three trial took place at 35 sites worldwide, and results showed significantly reduced destruction of red blood cells and increased hemoglobin levels. Children’s enrolled the most participants out of 274 total who were randomly assigned to receive an oral dose of 1500 mg of voxelotor, 900 mg of voxelotor, or a placebo once daily.
After 24 weeks of treatment, over 50% of patients receiving 1500 mg of voxelotor had a significant increase in hemoglobin compared with the placebo group. Follow up research is currently underway to extend voxelotor for those as young as age four.
The Children’s Sickle Cell Disease Program is the largest of its kind in the country, treating 1,900 children with SCD each year.
Voxelotor was funded and developed by Global Blood Therapeutics. Brown is a consultant to the company’s Executive Advisory Board. Voxelotor was approved by the FDA on Nov. 25, 2019.
To learn more about Children’s Sickle Cell Disease Program, visit: https://www.choa.org/sicklecell.