China Is Being, Well, China in the Investigation of Tainted Heparin

Chinese health officials continue to claim that the artificial contaminant, oversulfated chondroitin sulfate, in lots of Baxter's recalled heparin was not the cause of the 81 associated deaths and hundreds of allergic reactions that occurred in the United States, reports Reuters. The Chinese assertion comes in the wake of reports in the NEJM and Nature Biotechnology, which described the contaminant as structurally identical to a withdrawn intramuscular drug, Arteparon, and the contaminant's actions on the kinin-kallekrein pathway.

The Chinese food and drug agency points to the fact that only patients in the United States or Germany experienced adverse reactions to the tainted heparin, whereas the contaminant has been found in heparin products in other countries. The Chinese agency also claims that adverse reactions have occurred with some batches that did not contain the contaminant. Both of these assertions, however, have already been rebutted by the US FDA, which cited the relatively common practice of heparin bolusing in the United States and Germany and the initial use of an insufficiently sensitive test for the heparin contaminant.

In what appears to be a digressive move, Chinese officials accuse Baxter of obstructing their investigation of the company's tainted heparin, a charge that Baxter denies. A Chinese regulator is quoted by Reuters: "Baxter failed to provide necessary cooperation in the process of the investigation, which is not conducive to further identifying the reasons for the adverse reactions to heparin." Baxter is also accused of destroying some drug samples and relevant production records—an allegation also denied by the company. Chinese officials also point a finger at Baxter's Chinese heparin supplier Changzhou SPL, implying that the company avoided registration with China's food and drug administration because the company was considered a chemical manufacturer, not a drug maker.

Most important, however, Chinese health officials have yet to explain how the artificial contaminant made its way into heparin. Information to date suggests that the contaminant, which is considerably cheaper than crude heparin, was intentionally introduced into supplies at the workshop level, before processing at Changzhou SPL.