Seattle Genetics drug trials on hold after 4 people died

SEATTLE -- Bothell-based Seattle Genetics said Tuesday the U.S. Food and Drug Administration is putting a clinical hold on several trials after four people died.

Six patients with a type of blood cancer called acute myeloid leukemia (AML) have been identified with liver toxicity. The company says more than 300 patients have been treated in the clinical trials.

The company is now working with the FDA to identify whether the drug was the cause.

The clinical holds on these early-stage AML trials will evaluate the potential risk of liver toxicity in patients who were treated with the drug and had a stem cell transplant either before or after the treatment.

AML is a type of blood and bone marrow cancer that affects the growth of immature blood cells, according to Reuters. The disease most commonly occurs in adults and tends to increase with age.