Shares of Seattle Genetics fell nearly 15 percent on Tuesday after the U.S. Food and Drug Administration placed clinical holds on its SGN-CD33A drug for acute myeloid leukemia (AML).
The company announced that “hepatotoxicity” occurred in patients treated with SGN-CD33A. Six patients have been identified with hepatotoxicity — including several cases of veno-occlusive disease, the company wrote. Four patients have died.
“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,” the company wrote in a press release.
The company said that the “phase 1/2 trial of SGN-CD33A monotherapy in pre- and post-allogeneic transplant AML patients has been placed on full clinical hold.” Two of the company’s phase 1 trials have been placed on partial clinical hold, meaning no new enrollment and existing patients can continue with the trial with “re-consent.”
Shares of Seattle Genetics were trading at $52.88 on Tuesday morning, down more than 14 percent. The company is valued at $7.64 billion.