The FDA said it uncovered a second and unexpected cancer-causing impurity in three batches of the blood pressure medicine valsartan that were sold by Torrent Pharmaceuticals.
The testing, which was triggered by an inspection of the Zhejiang Huahai Pharmaceutical plant in China in 2017, has led to a number of recalls of the popular drug.
In its latest update of the ongoing investigation, the regulatory agency said the newest impurity to be found was N-Nitrosodiethylamine (NDEA), which is a known animal and suspected human carcinogen. The products tested were included in Torrent’s recall last month.
“As we continue to investigate the root cause of the impurities found in products that contain valsartan, our scientists are testing these products to better understand these impurities and to ensure they’re not present in other products,” Scott Gottlieb, M.D., FDA commissioner, said in a statement. “We’re also taking steps to make sure we’re providing stringent oversight of manufacturing processes to reduce the likelihood that impurities could be introduced into other products.”
The agency has said the tainted drug may have been on the market for years, and it will continue to update its list (PDF) of more than a dozen products that were sold in the U.S. that have been recalled.
Earlier this summer, the European Medicines Agency said that Huahai had told them it had identified NDMA in valsartan sold in the European market.
The FDA has said Huahai was not consistently quantifying or documenting impurities found in analytical testing, and that the plant’s equipment was not thoroughly cleaned. Paint chips were also discovered on some equipment during an inspection.