Members of the House Energy and Commerce Committee are expanding their investigation into the 2008 entry of contaminated heparin from China into the United States (US) market.

Heparin contaminated with overly sulfated chondroitin sulfate was linked to adverse reactions and the deaths of dozens of patients. FDA determined that the contaminant was deliberately introduced, but neither the source of the contaminant nor those responsible has ever been identified.

Members of the committee have sent letters to 10 companies requesting further information on the Chinese heparin industry and the Chinese heparin supply chain. Those companies include Amphastar Pharmaceuticals, Momenta Pharmaceuticals, Siegfried USA, Sagent Pharmaceutical, APP Pharmaceuticals, Sanofi, Drug Source, Global Pharma Sourcing, Pacific Rainbow, and Sandoz.

In a press release, committee leaders wrote: “We believe there is substantial public interest in solving this case. More than 80 percent of the [US] unfractionated heparin supply is sourced from China and more than 16 percent of [US] pharmaceutical ingredients are imported from China. There is reason to believe all or some of the individuals responsible for the adulteration are still actively engaged in the Chinese pharmaceutical supply chain and pose a continuing threat to pharmaceutical products imported to the [US]. How the heparin came to be contaminated and the exact nature of the contaminant remain unknown. It is important to determine how the adulteration happened so that industry and government can take more effective proactive measures to reduce the risk of such adulteration in the future.”