Based on new safety signals, Pfizer on Wednesday announced that Oxbryta’s overall benefit “no longer outweighs the risk” in patients with sickle cell disease. Guggenheim Securities analysts said the setback increases investor frustrations with the company’s business development track record.
Pfizer on Wednesday announced that it will withdraw its sickle cell disease therapy Oxbryta (voxelotor) from worldwide markets after new data showed a higher risk of deaths and complications in treated patients.
According to the company, new safety data for Oxbryta point to an “imbalance” of vaso-occlusive crises and mortality events in patients “which require further assessment.” Because of these findings, “the totality of the clinical data … now indicates the overall benefit of Oxbryta no longer outweighs the risk in the approved sickle cell patient population,” Pfizer said in its announcement.
Wednesday’s withdrawal will also affect all active clinical trials and expanded access programs of Oxbryta. The company has informed global health authorities about the new safety signals and the drug withdrawal, and it will continue to evaluate these new findings.
Pfizer CMO Aida Habtezion in a statement said that the decision to pull Oxbryta “is in the best interest of patients,” whose safety and well-being “is of the utmost importance” to the company. Patients on Oxbryta should discuss alternative treatment options with their physicians, Habtezion said.
Oxbryta’s withdrawal is unlikely to affect Pfizer’s 2024 guidance, according to the announcement.
Guggenheim Securities analysts wrote in an investor note that the financial impacts are likely to be “somewhat modest.” Still, another setback for the company’s business will “increase investor frustrations with Pfizer’s business development track record,” according to the analysts.
“The news will likely also raise additional questions on Pfizer’s ability to grow through the 2025-2030 time period when it is facing a number of patent expirations and other challenges to their current growth drivers,” the analysts noted.
Oxbryta is an orally available hemoglobin S polymerization inhibitor that works by suppressing the sickling of red blood cells. It was approved for the treatment of sickle cell disease (SCD) in November 2019, when it was still owned by Global Blood Therapeutics. Pfizer acquired the biotech in 2022 for $5.4 billion.
The withdrawal of Oxbryta will be a “significant blow” to patients with SCD ”who have been historically underserved,” BMO Capital Markets analyst Evan Seigerman wrote in an investor note.
There are new treatment options available, including two gene therapies—bluebird bio’s Lyfgenia (lovotibeglogene autotemcel) and Vertex Pharmaceuticals and CRISPR Therapeutics’ Casgevy (exagamglogene autotemcel)—that the FDA approved in December 2023.
Oxbryta’s new safety signals could also bring more scrutiny to these newer therapies, Seigerman wrote. “A similar lens is likely to be applied to gene therapies treating sickle cell disorder; although, these patients are generally sicker, which changes the conversation around risk/cost trade-off.”
