Oxbryta was a prescription drug manufactured by Pfizer and its 2022 acquisition, Global Blood Therapeutics (GBT) that was formulated to manage sickle cell disease. The drug was voluntarily recalled by the company in September 2024 after post-release studies and clinical patient data revealed instances of vaso-occlusive crises (VOCs), organ failure, and increased fatalities in test subjects and patients taking Oxbryta. Sickle cell disease is a hereditary blood disorder that deforms the patient’s red blood cells and impacts their ability to deliver oxygen to the body’s organs and tissues.
According to the Pfizer website:
“OXBRYTA (voxelotor) is an oral, once-daily therapy for patients with sickle cell disease (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 plaintiffs’ claims are focused in part on the Federal Drug Administration (FDA’s) expedited approval process. As a result of positive results in the early GBT-HOPE clinical trial that showed that Oxbryta significantly improved hemoglobin levels in sickle cell disease sufferers, the FDA exercised its “accelerated approval” process which permitted Pfizer and GBT to more quickly bring the drug to market for adults and children over the age of 12, while skirting some of the more stringent, longer term investigations typically required. In addition, a second study, the HOPE-KIDS study, prompted the FDA to approve the drug for children between the ages of 4 and 11. This accelerated approval process required further studies confirming a drug’s safety, however, and these aftermarket studies revealed serious problems.
The agency responsible for authorizing medication for human use in the European Union, the European Medicines Agency (EMA), after conducting its own review of Oxbryta, noted an increase in mortality among the drug’s users and recommended halting the drug’s production, which led to a ban in Europe and ultimately precipitated Pfizer’s global recall. In addition to the global recall, Pfizer has suspended all active clinical trials.
In response to the negative studies and clinical information, Pfizer stated:
“Pfizer’s 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. The data suggest an imbalance in vaso-occlusive crises and fatal events which require further assessment. Pfizer has notified regulatory authorities about these 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.”
Complaints that have been filed allege strict liability for design defect and failure to warn, negligence, breach of warranties, and violations of California consumer protection laws, including false advertising. Plaintiffs also allege that Pfizer and GBT knew of the risks associated with taking this drug and knowingly concealed them.
There are cases filed in both state and federal courts in a number of states including Illinois and California. It is anticipated that the Judicial Panel on Multidistrict Litigation (JPML) will ultimately consolidate these cases into an MDL. U.S. District Judge Trina L. Thompson, who is currently presiding over two of the federal cases in the Northern District of California, has set the first Oxbryta trial date of June 7, 2027.
