Pfizer Pulls Oxbrya from Market

Rare Daily Staff

Pfizer said that it is voluntarily withdrawing all lots of Oxbryta for the treatment of sickle cell disease and discontinuing all active clinical trials and expanded access programs for the drug worldwide.

Pfizer acquired Oxbryta when it purchased Global Blood Therapeutics for $5.4 billion in 2022.

The company said its decision was 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. The data suggest an imbalance in vaso-occlusive crises and fatal events that require further assessment.

Pfizer notified regulatory authorities about its findings and its decision to voluntarily withdraw Oxbryta 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. “Our primary concern is for patients who suffer from SCD, which remains a very serious and difficult-to-treat disease with limited treatment options.

The company is advising patients to contact their physicians to discuss alternative treatment while it continues to investigate the findings from its review of the data.

Pfizer said the decision is not expected to impact its full financial guidance for 2024.

Sickle cell disease is a lifelong, debilitating inherited blood disorder in which hemoglobin S polymerization leads to red blood cell sickling resulting in vascular inflammation and hemolytic anemia. Vascular inflammation, together with sickled RBC’s can lead to acute pain crises, or vaso-occlusive crises, and progressive end organ damage, including stroke. Complications of SCD begin in early childhood and are associated with shortened life expectancy. Early intervention and treatment of SCD have shown potential to modify the course of this disease, reduce symptoms and events, prevent long-term organ damage, and extend life expectancy.

Oxbryta is an oral, once-daily therapy for patients with SCD. Oxbryta works by increasing hemoglobin’s affinity for oxygen. Oxbryta inhibits sickle hemoglobin polymerization and the resultant sickling and destruction of red blood cells leading to hemolysis and hemolytic anemia, which are primary pathologies faced by every single person living with SCD.

The U.S. Food and Drug Administration in 2019 granted Oxbryta accelerated approval for the treatment of SCD in adults and children 12 years and older. It expanded that approval at the end of 2021 to include patients 4 years of age and older.