The U.S. Food & Drug Administration (FDA) has issued a Warning Letter to the Chinese manufacturer behind a global recall of contaminated valsartan tablets.
Valsartan is the generic name for Diovan, a prescription medication that treats heart failure and high blood pressure.
The Zhejiang Huahai Pharmaceutical Co. had, at one time, supplied Active Pharmaceutical Ingredient (API) for roughly half of the generic valsartan products sold in the United States.
In June, however, the company revealed that N-Nitrosodimethylamine (NDMA), a probable human carcinogen, had been detected in its valsaran API.
So far, generic drug makers in the United States and 21 other countries have announced valsartan recalls. In fact, products were added to the recall as recently as last week.
The FDA believes that the NDMA issue resulted from a change in Zhejiang Huahai Pharmaceutical’s manufacturing process, which occurred in 2014. As a result, contaminated valsartan was likely in circulation for the last four years.
The FDA has already banned Zhejiang Huahai Pharmaceutical’s API and other drug products from entering the country. The import ban followed an agency inspection that uncovered quality control issues at the company manufacturing plant in China.
The FDA’s November 29th Warning Letter resulted from the same inspection. According to the agency, the letter summarizes “significant deviations” from current good manufacturing practices. Among other things, Zhejiang Huahai Pharmaceutical failed to ensure that quality-related complaints were investigated and resolved.
In addition, the company did not evaluate the potential effects the manufacturing process change would have on the quality of its API.
“Your response states that predicting NDMA formation during the valsartan manufacturing process required an extra dimension over current industry practice, and that that your process development study was adequate,” the letter states. “We disagree. We remind you that common industry practice may not always be consistent with CGMP requirements and that you are responsible for the quality of drugs you produce.”
The FDA gave Zhejiang Huahai Pharmaceutical 15 days to respond to the Warning Letter.
“Specify what you have done since our inspection to correct your deviations and to prevent their recurrence,” the agency directed. “If you cannot complete corrective actions within 15 working days, state your reasons for delay and your schedule for completion.”
Zhejiang Huahai Pharmaceutical is also facing numerous valsartan lawsuits in courts throughout the United States. Most of these claims are class actions that seek restitution for people who purchased contaminated valsartan drugs. However, other plaintiffs allege the company’s tainted API caused their or a loved one’s cancer.
A motion before the U.S. Judicial Panel on Multidistrict Litigation seeks to centralize federal lawsuits stemming for the valsartan recall in a single court for coordinated pretrial proceedings. The Panel will likely rule on the motion early next year.