Pfizer has announced the global withdrawal of its sickle cell disease treatment, Oxbryta (voxelotor), which was priced at approximately $125,000 per year.
The decision follows a review of clinical data that revealed significant safety concerns, including an increased risk of complications and patient fatalities.
Oxbryta, initially priced at $10,417 per month, was hailed as a groundbreaking therapy when it received U.S. approval in 2019. Unlike previous treatments that addressed only the symptoms of sickle cell disease, Oxbryta was the first to target the underlying cause—red blood cells assuming an abnormal sickle shape.
By preventing red blood cells from becoming sickled, the drug aimed to reduce complications such as vaso-occlusive crises (VOC), which are painful episodes caused by blocked blood flow. These crises are a major cause of organ damage and early death among sickle cell patients.
Originally approved for use in adults and children aged 12 and older, Oxbryta received expanded FDA approval in December 2021 to include patients as young as four years old. Globally, the drug gained significant traction, receiving Priority Medicines (PRIME) designation from the European Medicines Agency (EMA) and orphan medicinal product status from the European Commission (EC). By February 2022, Oxbryta was granted marketing authorization in Europe for use in patients aged 12 and older, either as a monotherapy or in combination with hydroxycarbamide (hydroxyurea). Since its launch, the therapy has been approved in over 35 countries.
Despite its promising mechanism of action and global approvals, recent clinical data has cast a shadow over Oxbryta’s safety. In a key trial involving 236 patients, eight deaths were recorded in those taking Oxbryta, compared to two in the placebo group. Additionally, an increased incidence of VOC—a painful complication of SCD where sickled cells block blood flow—was observed in Oxbryta-treated patients. As a result, Pfizer has decided to halt all clinical trials, access programs, and the global availability of Oxbryta.
What to know
Pfizer has notified regulatory bodies and advised patients to consult with their healthcare providers to explore alternative treatments. An emergency meeting of the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) was scheduled to further assess the situation.
Despite generating $328 million in revenue from Oxbryta in 2023, Pfizer does not expect the withdrawal to impact its 2024 financial outlook. The decision underscores the complexities of developing therapies for rare diseases like SCD, where treatment options are limited and the risks of adverse effects must be carefully balanced against potential benefits.
While Oxbryta represented a significant advancement by addressing the root cause of sickle cell disease, its withdrawal reflects the ongoing challenges in finding safe, long-term solutions for the millions of patients affected by the condition worldwide.
