Pfizer Withdraws Oxbryta from All Markets

(Reuters) – U.S. drugmaker Pfizer (NYSE:PFE) announced on Wednesday its decision to withdraw its sickle cell disease treatment Oxbryta from all approved markets, citing risks of painful complications and potential fatalities.

Pfizer acquired Oxbryta, also known as voxelotor, during its $5.4 billion acquisition of Global Blood Therapeutics (NASDAQ:GBT) in 2022. The company generated $328 million in revenue from the therapy in full-year 2023.

In light of recent clinical data, Pfizer is discontinuing all studies and access programs related to the treatment, stating the benefits no longer outweigh the associated risks. The data revealed an imbalance in vaso-occlusive crises—a complication of the disease—and indicated “fatal events” that require further assessment.

Vaso-occlusive crisis occurs when blood flow is blocked, depriving tissues of oxygen and igniting an inflammatory response. This withdrawal precedes an extraordinary meeting on Thursday by the European health regulator’s Committee for Medicinal Products for Human Use to evaluate Pfizer’s drug.

In a study involving 236 participants, there were eight deaths among patients taking Oxbryta compared to two deaths in the placebo group. Pfizer stated it will reassess the available data and has alerted regulatory authorities about its findings. The company advised patients to consult their physicians about alternative treatments.

The U.S. Food and Drug Administration granted accelerated approval for Oxbryta in 2019, and it is also approved in Europe, the United Kingdom, and the United Arab Emirates. Oxbryta treats an inherited blood disorder characterized by sickle-shaped red blood cells, which can lead to strokes, organ damage, and early death.

Pfizer does not anticipate this withdrawal will impact its full-year 2024 financial outlook.