FDA approves drug to treat sickle cell disease in patients aged 4 up to 11 years

Action 

FDA has granted accelerated approval for Oxbryta (voxelotor) tablets to treat sickle cell disease in pediatric patients aged four up to 11 years. FDA had previously granted accelerated approval for Oxbryta for patients aged 12 years and older with sickle cell disease.  

Disease or Condition 

Sickle cell disease is a lifelong, inherited blood disorder that causes red blood cells to become abnormally sickle or crescent shaped. The abnormal shape restricts the flow of blood through vessels, limiting oxygen delivery to the body’s tissues. This leads to episodes of extreme pain and organ damage known as vaso-occlusive crises. The tissue damage is associated with severe and longstanding inflammation that worsens the vaso-occlusive crises.   

Effectiveness 

Oxbryta restores patients’ red blood cells a normal shape, thereby reducing damage to the body’s tissues and to red cells.  

The effectiveness and safety of Oxbryta was evaluated in a phase 2 trial of 45 patients aged four up to 11 years with sickle cell disease. Study participants received Oxbryta tablets for oral suspension based on body weight at the beginning of the trial. The evaluation of effectiveness was based on whether there was an increase of hemoglobin (iron-containing protein in red blood cells) greater than 1 gram per deciliter from the beginning of the trial to week 24. Thirty-six percent of patients reached this hemoglobin increase. As a condition of the accelerated approval, an ongoing study of Oxbryta must be completed to confirm that this hemoglobin increase leads to clinical benefit, such as an improvement in how patients with sickle cell disease feel or function.   

Safety Information 

People who have a history of allergic reactions to Oxbryta or its excipients must avoid Oxbryta because these individuals may develop a generalized rash, welts, shortness of breath, facial swelling, and higher than normal levels of eosinophils (a type of white blood cell). 

The most common side effects of Oxbryta are headache, vomiting, diarrhea, abdominal pain, nausea, rash, and fever.  

See the prescribing information for additional information on risks associated with Oxbryta. 

Designations 

Oxbryta was granted accelerated approval, which enables FDA to approve drugs for serious conditions to fill an unmet medical need based on a result that is reasonably likely to predict a clinical benefit to patients. Further clinical trials are required to verify and describe Oxbryta’s clinical benefit. 

FDA granted this application Breakthrough designation. Oxbryta also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.