A prominent consumer watchdog group is calling on the US Food and Drug Administration (FDA) to withdraw its approval of the diabetes drug Victoza (liraglutide), which it says is linked to acute pancreatitis and several deaths.
Victoza was approved by FDA in 2010 as a once-daily injectable treatment for Type 2 diabetes. The drug is an incretin mimetic drug known as a glucon-like peptide-1 (GLP-1) receptor agonist.
At the time of its approval, FDA noted that it had concerns about the drug's ability to cause pancreatitis in patients, and required the drug's sponsor, Novo Nordisk, to conduct a five-year epidemiological study using health claims to evaluate the drugs' association with the condition.
Out of the 3,900 clinical trial participants used to evaluate VIctoza, there were seven cases of pancreatitis reported. However, FDA said that this risk was not necessarily unique to Victoza, and that it had been observed in other diabetes drugs that worked "through similar mechanisms as Victoza."
Since its approval, however, the drug has been associated with more than a thousand cases of pancreatitis in the US, as well as another 332 reports of acute pancreatitis, based on data made available by FDA.
Those risks have been recognized by FDA in the past, such as a March 2013 safety communication indicating that the agency was investigating reports about an increased risk of pancreatitis associated with incretin mimetic drugs, including:
- liraglutide (Victoza)
- xenatide (Byetta, Bydureon)
- sitagliptin (Januvia, Janumet, Janumet XR, Juvisync)
- saxagliptin (Onglyza, Kombiglyze XR)
- alogliptin (Nesina, Kazano, Oseni)
- linagliptin (Tradjenta, Jentadueto)
FDA said that while the initial indications were not yet conclusive, it was cause enough for investigation.
Weeks after FDA's announcement, the European Medicines Agency (EMA) launched its own probe into the drugs, but in July 2013 said they were still safe for use, and that "Available data do not confirm recent concerns over an increased risk of pancreatic adverse events with these medicines."
However, other independent reports, such as one issued by the British Medical Journal, said that manufacturers had not generated sufficient data about the drugs, and that the dearth of promised data raised "serious questions about the safety of this class of drug."
Public Citizen: Denied Once, Back for More
In the midst of these safety issues has been Public Citizen, a public advocacy group that has historically taken a highly risk-averse stance toward the approval of new medicines.
In 2012, the group filed a Citizen Petition with FDA calling on the agency to ban Victoza, saying that its "serious safety concerns … outweigh any of liraglutide's marginal benefits."
On 25 March 2014, FDA denied Public Citizen's petition, saying that the concerns raised by the group had been "appropriately and thoroughly considered at the time of [the drug's] initial approval." FDA also said various changes to the drug's labeling since its approval, such as an April 2012 update pertaining to pancreatitis, has alleviated other concerns.
And, FDA said, the agency was "continuing to evaluate pancreatitis to determine if further regulatory action is required."
But that "further action" was not—at least at the time—going to involve withdrawal of the drug in its entirety.
So now Public Citizen is trying to get the drug removed from the market again, this time buttressing its application with data it obtained from the agency's MedWatch database, as well as data from the French national drug surveillance database.
"While previous studies have analyzed only the electronically available AERS data summaries on pancreatitis with liraglutide and other incretin mimetics, none have previously examined the full MedWatch reports themselves, making it difficult for the researchers who conducted these earlier studies to discern whether other potential causes of pancreatitis were involved," Public Citizen wrote.
This data, the group said in a statement, demonstrates that "pancreatitis adverse events seem unique to the incretin mimetic class of diabetes drugs, with much lower numbers of cases occurring in diabetics taking other drugs for their disease."
"These results suggest a causal link between liraglutide and the occurrence of acute pancreatitis," they wrote in their report.
The drug was prescribed more than 2.6 million times in 2013, the group noted, and is also being considered later this year for a proposed weight loss indication at a dose almost twice the level as its currently approved dose for diabetes.