FDA Approves Voxelotor for Sickle Cell Disease

The US Food and Drug Administration (FDA) has granted an accelerated approval to voxelotor (Oxbryta) for the treatment of sickle cell disease in patients aged 12 years and older.

The approval, granted under the FDA’s Accelerated Approval pathway, proceeds the Global Blood Therapeutic drug’s Fast Track and Orphan Drug designations.

The therapy works as a deoxygenated sickle hemoglobin polymerization inhibitor—playing a critical role in limiting sickle cell disease’s central abnormality, Richard Pazdur, MD, director of the FDA's Oncology Center of Excellence, acting director of the Office of Oncologic Diseases in the FDA's Center for Drug Evaluation and Research, said.

“With Oxbryta, sickle cells are less likely to bind together and form the sickle shape, which can cause low hemoglobin levels due to red blood cell destruction,” Pazdur said in a statement. “This therapy provides a new treatment option for patients with this serious and life-threatening condition."

Its approval was based on the findings of a 274-patient clinical trial assessing 1500 mg (n = 90) and 900 mg (n = 92) doses versus placebo (n = 92). In assessing for effectiveness—based on an increased hemoglobin response rate—a significantly greater rate of patients administered 1500 mg voxelotor (51.1%) responded, versus placebo patients (6.5%).

The lifelong, inherited blood disorder is characterized by restricted blood vessel flow, limited oxygen delivery to the tissues, severe pain, organ damage, and chronic inflammation. The approval of voxelotor provides “additional hope” to the approximate 100,000 US patients burdened with the disease, acting FDA commissioner Brett P. Giroir, MD, said.

“Our scientific investments have brought us to a point where we have many more tools available in the battle against sickle cell disease, which presents daily challenges for those living with it,” Giroir said. “We remain committed to raising the profile of this disease as a public health priority and to approving new therapies that are proven to be safe and effective.”