[9/26/2024] FDA is alerting patients, caregivers, and health care professionals that Oxbryta (voxelotor) is being voluntarily withdrawn from the market by the manufacturer due to safety concerns. Health care professionals should stop prescribing Oxbryta. Patients and caregivers should contact their health care professional about stopping Oxbryta and starting another treatment option.

Pfizer Inc., the manufacturer of Oxbryta, announced it is voluntarily withdrawing the medication from the market, ceasing distribution, and discontinuing all active clinical trials and expanded access programs for Oxbryta because recent data indicate the benefit of Oxbryta does not outweigh the risks for the sickle cell patient population.

In postmarketing clinical trials of Oxbryta, Pfizer reported a higher rate of vaso-occlusive crisis (severe pain caused by sickled red blood cells blocking blood flow and oxygen delivery to tissues) in patients with sickle cell disease receiving Oxbryta compared to placebo. There were also more deaths in the Oxbryta treatment group as compared to the placebo group in these postmarketing studies. Pfizer also observed a higher rate of vaso-occlusive crisis in patients with sickle cell disease receiving Oxbryta in two real-world registry studies. Based on the totality of clinical data, Pfizer has determined the benefit of Oxbryta does not outweigh the risk.

FDA has been conducting a safety review of the postmarketing clinical trial data for Oxbryta, the real-world registry studies, as well as postmarketing data from the FDA Adverse Event Reporting System (FAERS). At the conclusion of this safety review, FDA will communicate any additional findings, if necessary.

FDA approved Oxbryta under the accelerated approval pathway in 2019 for the treatment of sickle cell disease in adults and pediatric patients 12 years of age and older. In 2021, FDA granted accelerated approval of Oxbryta for the treatment of sickle cell disease in patients 4 to 11 years of age. Accelerated approval is based on a surrogate or intermediate clinical endpoint that is reasonably likely to predict clinical benefit, allowing for earlier approval of drugs that treat serious conditions and fill an unmet medical need. In general, FDA requires postmarketing studies to verify and describe the clinical benefit of medications approved under this program.

FDA understands the importance of having safe and effective medications available to improve the health of patients living with this rare, serious disease. There are other FDA-approved medications for the treatment of sickle cell disease, which health care professionals may prescribe as an alternative treatment to Oxbryta.

FDA encourages Health care professionals and patients to report adverse events or quality problems experienced with the use of Oxbryta to the FDA’s MedWatch Adverse Event Reporting program by:

• Completing and submitting the report online at www.fda.gov/medwatch/report.htm;
  or
• Downloading and completing the form, then submitting it via fax at 1-800-FDA-0178.