On September 25, U.S. pharmaceutical giant Pfizer announced the withdrawal of its sickle cell disease treatment, Oxbryta (voxelotor), from all markets where it is approved, citing risks of painful complications and death. Pfizer had acquired Oxbryta in 2022 through its $5.4 billion buyout of Global Blood Therapeutics, generating $328 million in revenue from the drug in 2023.

Pfizer is discontinuing all related studies and access programs, stating that clinical data now indicates the risks outweigh the benefits. The data revealed an imbalance in the occurrence of vaso-occlusive crises, a complication where blocked blood flow deprives tissues of oxygen, causing inflammation. There were also reports of fatal events that require further evaluation.

The withdrawal precedes an extraordinary meeting of the European Medicines Agency’s Committee for Medicinal Products for Human Use, scheduled to review the drug. A study involving 236 patients showed eight deaths among those on Oxbryta, compared to two in the placebo group. Pfizer has informed regulatory authorities and advised patients to consult their physicians for alternative treatments. Oxbryta received accelerated approval from the U.S. FDA in 2019 and is also approved in Europe, the UK, and the UAE.

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