SAN FRANCISCO(AP) _ Federal regulators said Friday night they are investigating allegations that at least 13 vials of an immune deficiency treatment drug made by Bayer Corp. may have been tampered with by someone outside the company.
Bayer said someone diluted at least 13 vials of its liquid drug Gamimune N with saline. The company is recalling about 8,000 of the vials distributed nationwide, and the Food and Drug Administration is investigating.
Bayer said it knew of no patients harmed by the diluted drug, and was unsure what effects it would have on a patient.
Gamimune N is used by about 20,000 patients with weakened immune systems, including bone marrow transplant recipients.
Bayer said it believes the tampering occurred after the drug left its North Carolina plant and is limited to two lots handled by a single distributor, which the company refused to identify.
''We have really isolated this incident to the two lots,'' said company vice president Michael Fournel. ``We have no reason to believe the other lots are affected.''
Bayer makes two million vials of Gamimune N each year.
The FDA said it is comfortable with Bayer's limited recall decision.
``I think at this point the information indicates that the actions taken by Bayer are appropriate,'' said Steve Masiello, director of the office of compliance and biologics quality.
Bayer said customer complaints earlier this year that their vials of Gamimune N contained uncharacteristically cloudy liquid prompted it to recall one lot on Feb. 1. Fournel said the company has since received 500 vials from that first lot. Several of those vials showed obvious signs of tampering, Fournel said.
Bayer began recalling the second lot Thursday. Fournel said the company waited that long because it didn't conclude until Monday that someone had tampered with the drugs.
Earlier this month, a Kansas City, Mo., pharmacist pleaded guilty to diluting two chemotherapy drugs made by Eli Lilly and Co. and Bristol-Myers Squibb. Prosecutors said Robert Courtney made hundreds of dollars extra per dose.
Pittsburgh-based Bayer Corp. is a subsidiary of German conglomerate Bayer AG. The company voluntarily removed the anti-cholesterol treatment Baycol from the U.S. market last August after the FDA linked it to 31 deaths.