FDA says contaminant in some Baxter heparin

WASHINGTON (Reuters) - U.S. regulators on Wednesday said they identified a contaminant in the key ingredient in Baxter International's recalled blood thinning drug heparin amid 15 more reports of deaths in patents treated with some version of the drug.

The contaminant, a large complex molecule chemically similar to heparin, was detected in samples from a Chinese and a U.S. plant, both owned by Baxter's supplier, Wisconsin-based Scientific Protein Laboratories LLC (SPL).

"At this point we don't know how the heparin-like compound got into the active pharmaceutical ingredient," Food and Drug Administration Deputy Commissioner Janet Woodcock told reporters on a conference call. "We don't yet have a direct causal link between the contaminant and the adverse events."

Nineteen deaths have been reported in patients taking a version of heparin that appear related to the drug, though it is unknown if all of those patients were on Baxter's heparin or another product.

The other major U.S. heparin supplier, APP Pharmaceuticals Inc, ramped up production to avoid a drug shortage after Baxter recalled most of its heparin products last week.

Tests on APP's heparin have not turned up any contamination, Woodcock said.

The FDA's foreign inspection process has been criticized for years as inadequate and those complaints were stoked when FDA officials acknowledged recently the agency never inspected the Chinese plant in question because of confusion over the company's Chinese name.

FDA has not yet sifted through the 785 total adverse event reports in heparin patients to determine which are drug-related, Woodcock said.

She cautioned that increased attention to the problem has led to an influx of side-effect reporting and that may not be related to the drug.

Heparin is derived from pig intestines and is used in dialysis and heart procedures, among other surgeries, to avoid blood clots.

Last week, the FDA said it found "objectionable conditions" at the plant. Facility owner Scientific Protein Labs in a statement said the contaminant theory is "speculation at this point" and that it is working with the FDA to determine the cause of the problems.

FDA officials also don't know whether the contaminant was added intentionally or if it occurred as part of a natural biological process.

"We still don't know whether this inadvertently got into the supply or whether it was actually added" deliberately, Woodcock said.

Severe reactions such as anaphylaxis and low blood pressure are signs of dangerous allergic reactions related to heparin use.

Earlier on Wednesday, Baxter, which has recalled most of its heparin blood thinning products, said it narrowed down possibilities for the root causes.

Baxter ruled out its Cherry Hill, New Jersey, facility, where the drug is manufactured in a later step in the process, as a source of the problem.

(Reporting by Kim Dixon; Editing by Brian Moss)