Counterfeit versions of the cancer drug Avastin are being distributed in the United States, government regulators warned Wednesday.

The U.S. Food and Drug Administration issued a warning to consumers about the fake versions of Avastin; the real drug is used to treat colon, lung, kidney and brain cancers,

The fake Avastin does not include the key active ingredient, The Associated Press reported.

FDA official warned that consumers need to be on the lookout for Avastin with lot numbers B86017, B6011 and B6010 and with product packaging that labels Roche as the manufacturer.

The FDA also issued letters to 19 medical practices across the U.S. that purchased unapproved cancer medications that may have included the fake Avastin.

For more information, visit the FDA website.