Pfizer Withdraws SCD Drug Due to Safety Concerns

Pfizer is voluntarily withdrawing all lots of voxelotor (Oxbryta) for the treatment of sickle cell disease (SCD) in all approved markets. The company is also discontinuing all active clinical trials and expanded access programs for the drug worldwide.

The decision was based on the totality of clinical data, which now indicates that the benefits of Oxbryta no longer outweigh its risks as a treatment for SCD. Postmarketing trials revealed a higher rate of vaso-occlusive crises and more deaths in patients treated with voxelotor compared with placebo, according to the Food and Drug Administration. Pfizer reported similar findings in real-world registry studies.

Voxelotor received accelerated approval in 2019 for adults and pediatric patients aged 12 years and older, and in 2021 for children aged 4 to 11 years. The accelerated approval allowed for earlier access to the drug based on surrogate endpoints, with postmarketing studies required to verify the drug's clinical benefit.

FDA is conducting an ongoing safety review of this data and is reviewing reports from the FDA Adverse Event Reporting System (FAERS). The agency will communicate any additional findings as necessary.