The U.S. FDA imposed a clinical hold on several Seattle Genetics Inc. trials evaluating the SGN-CD33A treatment for acute myeloid leukemia, a type of blood and bone marrow cancer.
The halt was initiated to assess the potential risk of hepatotoxicity, or chemical-driven liver damage, in patients who were treated with the drug and received stem cell transplants either prior to or after treatment.
Six patients were identified with hepatotoxicity, including several cases of veno-occlusive disease, with four fatal events, the company said.
As a result, two phase 1 trials have been placed on partial clinical hold while another phase 1/2 trial has been placed on full clinical hold.
Seattle Genetics is working with the regulator to determine a link between hepatotoxicity and the treatment to identify measures for patient safety.
Seattle Genetics' phase 3 trial of the drug in patients with acute myeloid leukemia and phase 1/2 trial in patients with myelodysplastic syndrome, another bone marrow disorder, are continuing.
New trials will not be initiated until the holds are lifted.