Pfizer’s abrupt withdrawal of Oxbryta, a drug for sickle cell disease, has sent shockwaves through the medical community.

Pfizer withdrew its pill for sickle cell disease amid heightened European scrutiny, triggered by death rates seen in clinical studies.

The U.S. Food and Drug Administration on Thursday alerted patients and healthcare professionals about the withdrawal of Pfizer's sickle cell disease treatment Oxbryta. Pfizer said late on Wednesday it was pulling the drug from all markets due to risk of a painful complication and death.

The healthcare company said clinical data indicates the overall benefit of Oxbryta no longer outweighs the risk in the approved sickle cell patient population.

Pfizer’s sudden market withdrawal of sickle cell therapy Oxbryta, which some analysts predicted would reach $750 million in sales by the end of the decade, has left patients and healthcare providers with few options,

Pfizer will voluntarily pull its sickle cell disease (SCD) drug Oxbryta from all markets worldwide, a major blow to a $5.4 billion acquisition the New York pharma made two years ago. | Pfizer will voluntarily pull its sickle cell disease drug Oxbryta from all markets worldwide,

Pfizer has announced the withdrawal of all lots of OXBRYTA approved for treating sickle cell disease (SCD) from worldwide markets.

Agios Pharmaceuticals (AGIO) stock was downgraded at Leerink Partners on Pfizer's (PFE) recent decision to withdraw sickle cell disease drug, Oxbryta. Read more here.

European regulators on Thursday also said that patients in the trials had higher rates of the pain crises that are hallmarks of sickle cell disease once they started on Oxbryta, also called voxelotor,