Seattle Genetics, Inc. announced that it has received notice from the U.S. Food and Drug Administration (FDA) that a clinical hold or partial clinical hold has been placed on several early stage trials of vadastuximab talirine (SGN-CD33A) in acute myeloid leukemia (AML). The clinical holds were initiated to evaluate the potential risk of hepatotoxicity in patients who were treated with SGN-CD33A and received allogeneic stem cell transplant either before or after treatment. Six patients have been identified with hepatotoxicity, including several cases of veno-occlusive disease, with four fatal events. Overall, more than 300 patients have been treated with SGN-CD33A in clinical trials across multiple treatment settings. Seattle Genetics is working diligently with the FDA to determine whether there is any association between hepatotoxicity and treatment with SGN-CD33A, to promptly identify appropriate protocol amendments for patient safety and to enable continuation of these trials.


