Pfizer has voluntarily suspended marketing of its sickle-cell drug, Oxbryta (voxelotor), on a global basis based on a clinical benefit–risk assessment. The company had acquired the drug as part of its $5.4-billion acquisition of Global Blood Therapeutics, a San Francisco, California-based bio/pharmaceutical company, in 2022. 

Pfizer is also discontinuing all active clinical trials and expanded access programs worldwide for the drug.  

Pfizer says its decision is based on the totality of clinical data that now indicates the overall benefit of Oxbryta no longer outweighs the risk in the approved sickle-cell patient population. In 2019, the US Food and Drug Administration (FDA) granted accelerated approval for Oxbryta tablets for the treatment of sickle-cell disease in adults and children aged 12 years and older. In December 2021, the FDA expanded the approved use of the drug for the treatment of sickle-cell disease in patients four years of age and older. 

The company said that the data suggest an imbalance in vaso-occlusive crises and fatal events that require further assessment. Pfizer says it has notified regulatory authorities about these findings and its decision to voluntarily withdraw the drug from the market and discontinue distribution and clinical studies while further reviewing the available data and investigating the findings. 

“The safety and well-being of patients is of the utmost importance to Pfizer, and we believe this action is in the best interest of patients,” said Aida Habtezion, Chief Medical Officer and Head of Worldwide Medical and Safety at Pfizer, in a September 25, 2024, company statement. “Our primary concern is for patients who suffer from SCD [sickle-cell disease], which remains a very serious and difficult-to-treat disease with limited treatment options. We advise patients to contact their physicians to discuss alternative treatment while we continue to investigate the findings from our review of the data.” 

Oxbryta was a key piece of Pfizer’s $5.4-billion acquisition of Global Blood Therapeutics, which the company acquired to boost its position in rare hematology disorders. At the time of the acquisition in 2022, the company said that Oxbryta, along with the rest of Global Blood Therapeutics’ sickle-cell disease pipeline, could potentially achieve combined worldwide peak sales of more than $3 billion. In 2023, Oxbryta had global sales of $328 million. 

Pfizer says that it does not anticipate that this event will impact its full-year 2024 financial guidance. 

Source: Pfizer