Pfizer said it will withdraw its sickle cell disease treatment Oxbryta from all markets worldwide, after data showed an “imbalance” of fatalities and complications common to the disease.
The surprise decision is likely to significantly diminish the value of Pfizer’s $5.4 billion purchase of Global Blood Therapeutics in 2022, which brought Oxbryta to the New York drugmaker, and which Pfizer touted at the time as building out its rare disease and hematology portfolio.
In an announcement Wednesday, Pfizer said the data suggest Oxbryta’s benefit “no longer outweighs the risk” in sickle cell, a life-threatening group of inherited blood disorders in which red blood cells become misshapen. The company has also discontinued all active clinical trials and expanded access programs.
Oxbryta, also known as voxelotor, had been under review by the European Medicines Agency for months following patient deaths in two clinical trials. One trial recruited 236 patients at a higher risk of stroke, and resulted in eight deaths in the treatment arm versus two in the placebo arm, the EMA said in July. Another study in leg ulcers recruited 88 patients and saw eight deaths in the open-label portion of the trial.
Aida Habtezion“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,” Pfizer CMO Aida Habtezion said in a news release on Wednesday.
The drug generated $328 million in 2023 sales for Pfizer.
While Oxbryta was approved in 2019, patients now have newer options. The FDA approved the first two gene therapies for sickle cell last year, Lyfgenia and Casgevy. But those products have been slow to launch, and the number of patients treated by them since approval was counted in the dozens last month.
European regulators said in July that no evidence tied Oxbryta to the deaths, noting that some may have been caused by infections such as malaria. The agency had planned to meet on Thursday to discuss the data. It’s unclear whether the meeting is still set to occur, though Endpoints News has reached out to the agency and will update this story accordingly.
“We advise patients to contact their physicians to discuss alternative treatment while we continue to investigate the findings from our review of the data,” Habtezion said.