Pfizer Inc. (NYSE: PFE) announced today that it is voluntarily withdrawing all lots of OXBRYTA ^® (voxelotor) for the treatment of sickle cell disease (SCD) at this time, in all markets where it is approved. Pfizer is also discontinuing all active voxelotor clinical trials and expanded access programs worldwide.

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.

“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,” said Aida Habtezion, Chief Medical Officer and Head of Worldwide Medical and Safety at Pfizer. “Our primary concern is for patients who suffer from SCD, which remains a very serious and difficult-to-treat disease with limited treatment options. We advise patients to contact their physicians to discuss alternative treatment while we continue to investigate the findings from our review of the data.”