Public Citizen, the Washington, D.C.-based consumer advocacy group, is petitioning the FDA to immediately remove the type 2 diabetes drug Victoza (liraglutide) from the market. The petition claims that the injectable medication puts patients at risk of thyroid cancer, pancreatitis, serious allergic reactions, and kidney failure.

"More and more people are taking this drug, and more people are experiencing serious health problems as a result," Public Citizen director Sidney Wolfe, MD, said in a statement. "Clearly, the FDA's warning system is not sufficient. The drug should be taken off the market."

Novo Nordisk, the drug's manufacturer, strongly disputes Public Citizen's statement.
Victoza's Safety Profile

The drug's label currently warns patients and doctors that Victoza caused thyroid tumors and cancer in animal studies involving rats and mice. The label then states that it is unknown whether people taking the drug are at similar risk of such tumors and cancer, which can be fatal if not caught and treated early. It advises patients with a family history of such disease to avoid the drug and warns patients to see a doctor if suspicious lumps or other symptoms occur while taking the medication.

Pancreatitis, a severe and sometimes fatal inflammation of the pancreas, is also a possible side effect of Victoza. According to Public Citizen, patients taking Victoza were nearly four times as likely to be diagnosed with acute pancreatitis than patients taking other diabetes drugs. In the 17 months following the drug's 2010 approval, 200 patients reported having acute pancreatitis. Public Citizen believes that the real number of cases may be much higher.

"Because only an estimated 10% of cases are reported, potentially as many as 2,000 patients or more have suffered a painful and serious outcome as a result of taking Victoza," according to the statement from Public Citizen.

Victoza, which patients inject once a day, is one of a class of drugs that works by mimicking the hormone GLP-1. GLP-1 triggers the production of insulin when blood sugar levels rise too high. It is not a "first choice" medication, and doctors are advised to prescribe it only after other medications prove ineffective.
Victoza Maker Responds

The drug's maker, Novo Nordisk, disputes Public Citizen's claim that the drug should be pulled from the market.

"Novo Nordisk is committed to patient safety and rejects Public Citizen's assertion that the benefits of Victoza are outweighed by its risks," the company states in an email to WebMD. "In the two years since Victoza was approved, Novo Nordisk has continued to work closely with the FDA and the medical community to monitor the benefits and appropriate use of Victoza. Our experience in those two years does not support the Public Citizen call to deprive patients of the benefits of Victoza."

The FDA declined to comment. A representative of the agency said the FDA would respond directly to Public Citizen after reviewing the petition.

Victoza in Clinical Practice

Endocrinologist Suneil Koliwad, MD, PhD, says that plenty of drugs effectively treat type 2 diabetes, and he sees no reason to "aggressively defend" the use of Victoza. Compared to drugs that have long and proven safety records, he says, Victoza's safety is not thoroughly established, and he is particularly concerned about inflammation of the pancreas.

"The drug's trial was not long enough to see a sufficient safety record," says Koliwad, an assistant professor of medicine at the University of California San Francisco's Diabetes Center. "How rare is rare enough that we accept safety risks and still give this to our patients? Some medications we do give because they are the best available. Here that is not the case."

Koliwad says that some patients may benefit from Victoza and drugs in its class, but they should be thoroughly counseled prior to taking it. And he says that doctors should look at all of the available drugs before prescribing Victoza and similar medications. For those patients taking it already, Koliwad says they should stay on it if it works and is not causing problems.

"The primary concern should be that you are controlling your diabetes," says Koliwad.

Spyros Mezitis, MD, PhD, agrees.

"If there are no issues, we continue patients on the drug and we continue monitoring them while on it," says Mezitis, an endocrinologist at Lenox Hill Hospital in New York City who prescribes Victoza to patients only after a comprehensive discussion of their family health history, particularly regarding their thyroid.

Mezitis says the drug's label clearly states the safety profile of Victoza, and that the post-marketing safety reports do not yet make a strong enough case for the drug's withdrawal from the market.

"But if studies show that pancreatitis and thyroid cancer are directly related to Victoza, that would be a different story," says Mezitis.