An Amgen television ad for its psoriasis drug Enbrel is misleading and plays down the drug’s very serious risks, the U.S. Food and Drug Administration said on Friday.

The FDA also invited Amgen to prove claims made by the “Freedom” advertisement that the drug can completely clear up the red, raised lesions caused by psoriasis.

And the agency told the company to stop calling the drug a “breakthrough” because there are several rivals on the market that do the same thing for psoriasis.

“The TV ad overstates the effectiveness of Enbrel, fails to communicate the limitations of the indication, thereby broadening the indication, and it minimizes the risks associated with the drug,” the FDA said in an official warning letter to the company.

A spokeswoman for Amgen said the ad had been withdrawn and the company was reviewing the FDA letter.

Enbrel, known generically as etanercept, works to treat a range of autoimmune diseases by blocking an inflammation-causing protein called tumor necrosis factor. These diseases, which include psoriasis and rheumatoid arthritis, occur when the body’s immune system mistakenly attacks healthy tissue.

Enbrel and rival drugs, which include Abbott Laboratories Inc.‘s Humira, and Johnson & Johnson’s Remicade, interrupt this immune process, although via different pathways. In doing so, they may make a patient more susceptible to other diseases such as tuberculosis and cancer.

Amgen, which markets Enbrel along with Wyeth, says Enbrel has been taken by 280,000 people.

The FDA said it was unhappy with the Enbrel television ad for several reasons, including confusing graphics and overly optimistic claims.

Vignettes of supposed patients show healthy, clear skin with no lesions. “The overwhelming impression conveyed by the TV ad is that Enbrel completely clears skin with psoriasis. Other parts of the TV ad reinforce this message,” the FDA said.

“We are not aware of substantial evidence or substantial clinical experience demonstrating that Enbrel can provide complete clearing. If you have data demonstrating this benefit, please submit them to FDA for review,” the FDA said in its letter.

“The claim that Enbrel can dramatically clear skin ‘fast’ also is misleading because consumers are not likely to interpret this claim as meaning that clinical response occurs after two months of treatment as was demonstrated in clinical trials,” the agency added in the warning letter.

It noted that Enbrel carries strong warnings in its label, including one about the risk of tuberculosis. Patients who use the drug have triple the expected risk of lymphoma cancers and it is not clear whether the drug’s actions are responsible, the FDA said.