Novo Nordisk has spoken out in support of Victoza after influential US consumer group Public Citizen called for the diabetes drug to be withdrawn.

Public Citizen has asked the US Food and Drug Administration to immediately remove Victoza (liraglutide) from the market "because it puts patients at higher risk of thyroid cancer, pancreatitis, serious allergic reactions and kidney failure that outweigh any documented clinical benefit". The advocacy group claims that the once-daily human glucagon-like peptide-1 (GLP-1) analogue "is the only drug approved by the FDA or in the approval pipeline that causes thyroid C-cell tumours in both sexes of rats and mice, doing so at drug exposures similar to those seen in people taking the recommended dose – a striking warning sign".

Also, in the first 17 months of Victoza being on the market, 200 patients were diagnosed with acute pancreatitis, according to Public Citizen’s review of the FDA’s adverse event database. Because only 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", the group claims.

Sidney Wolfe, director of Public Citizen’s Health Research Group, said that “the FDA’s frequent solution to serious safety issues identified with new drugs is reckless: the agency simply describes the risks in the drug label and hopes that physicians and patients will pay attention".

He notes that "more and more people are taking this drug, and more people are experiencing serious health problems as a result. Clearly, the FDA’s warning system is not sufficient. The drug should be taken off the market.” Some 150,000 prescriptions for Victoza are now being filled each month, which translates into two million a year.

However the Danish drugmaker rejects Public Citizen’s assertion. It notes that when it approved Victoza two years ago, the FDA had before it "a large amount of data, including clinical trials in nearly 4,000 patients".

As part of its usual process, Novo says the agency "carefully assessed all of the data and approved Victoza with labelling that informs physicians and people with diabetes about the appropriate use of the product". In the two years since approval, Novo says it has continued to work closely with the FDA and the medical community and "our experience in those two years does not support the Public Citizen call to deprive patients of the benefits of Victoza.

Indeed, Novo noted that just last week, it received a product label update for Victoza to include data showing its superior efficacy when compared with Merck & Co's rival drug Januvia (sitagliptin). The firm's chief science officer Mads Krogsgaard Thomsen told Reuters that Public Citizen had referred to old data from studies on mice and rats which had no relevance to the use of Victoza in humans.

He went on to say that "we do not expect any consequences for Victoza from Public Citizen's petition. There is nothing in it."