The Food and Drug Administration (FDA) has put a clinical hold on several early stage studies on an experimental cancer drug conducted by Seattle Genetics Inc. Four participants in the clinical study have died due to liver toxicity that may be linked to the drug.
The study is evaluating the drug’s effect on patients with acute myeloid leukemia (AML), a type of blood cancer. Six of the study’s patients have been diagnosed with liver toxicity and four patients have died. The company is cooperating and working with the FDA to determine if the cause of liver toxicity can be linked to the drug.
Managing Director of advisory firm Guggenheim Partners, Tony Butler, has stated that the liver toxicity is likely drug dependent and that Seattle Genetics should consider lowering the dosage or dosage intervals. He also claimed, according to CNBC, that the outcome “places a risk on whether the program is able to continue.”
Chad Messer, a representative of Needham & Co, had a contrasting message for investors in Seattle Genetics after the company’s shares fell around 16 percent. Messer reminded investors that liver toxicity is a known side effect in stem cell transplant patients.
The drug in question, Vadastuximab Talirine, is an antibody-drug conjugate which, unlike chemotherapy, is designed as a targeted therapy to kill only cancer cells, not healthy cells. The drug has been tested and observed in over 300 patients with AML, a bone marrow cancer that impacts the growth of blood cells.
The U.S. FDA and the European Union have granted the drug an orphan designation for the treatment of AML and myelodysplastic syndrome, another form of blood cancer.
The trial hold will not affect patients participating in an ongoing late-stage study of the drug in older AML patients.