EMA to review Pfizer's Oxbryta after patient deaths

The European Medicines Agency (EMA) is set to convene on Thursday to discuss Oxbryta, a treatment for sickle cell disease that Pfizer acquired through its $5.4 billion purchase of Global Blood Therapeutics. This meeting follows the occurrence of patient fatalities in two clinical trials involving the drug.

In July, the EMA initiated a review of Oxbryta, also known by its scientific name voxelotor, after observing a higher death rate among participants in the treatment arm compared to the placebo group in one of the trials. This particular trial focused on patients with an elevated risk of stroke. Additionally, another study involving patients with leg ulcers reported an unexpectedly high number of deaths. At the time, regulators highlighted that there was no direct evidence linking Oxbryta to these fatalities, suggesting that some deaths could have been due to infections such as malaria.

Following these findings, the EMA halted Oxbryta treatment in both studies. The stroke risk trial, which included 236 participants from Egypt, Ghana, Kenya, Nigeria, Oman, Saudi Arabia, the US, and the UK, reported eight deaths in the treatment group versus two in the placebo group as of July 29.

The leg ulcer study involved 88 patients from Brazil, Kenya, and Nigeria. By the end of July, eight deaths had occurred in the open-label portion of this study, as reported by the EMA.

Pfizer came into possession of Oxbryta in 2022 after completing a $5.4 billion acquisition of Global Blood Therapeutics. The company has declined to make any comments ahead of the upcoming EMA meeting.