WASHINGTON (AP) - Counterfeit versions of the popular cancer drug Avastin obtained by European regulators contain a variety of chemicals, but not the active ingredient found in the genuine drug, according to drugmaker Roche.
The Swiss drugmaker said in a statement an analysis of the contents of the vials picked up traces of 10 substances, ranging from starch and salt to chemicals like acetone, a solvent used in paint thinner.
Roche said it is unclear whether the substances would cause harmful effects in patients.
"None of the vials tested contained the active ingredient for Avastin or any protein or biologic drug," the company stated, following an analysis of three vials obtained by British authorities. "The counterfeit product is not safe or effective and should not be used."
Avastin is used to treat cancers of the colon, lung, kidney and brain. The drug is one of the most widely used cancer drugs in the world, generating about $6 billion a year in sales.
The Food and Drug Administration is investigating the source of counterfeit Avastin imported and distributed by a U.S. wholesaler to doctors here. Authorities in Europe have traced the counterfeit product back through distributors in Britain, Denmark and Switzerland. The original country of origin is still unclear.
Dr. Philip Cole of Johns Hopkins University said several of the substances appear to be common to biotech drugs, including starch, salt and benzoic acid.
"But I don't think any of them are useful for getting the functional effect of Avastin," said Cole, who directs the pharmacology program at Johns Hopkins School of Medicine.
Cole said the presence of acetone was concerning, since it does not have a medical use.
"We do make some acetone in our bodies as a byproduct of various metabolic pathways," Cole said. "Small quantities are not dangerous, but it certainly can be toxic at higher levels."