FDA reviewers are questioning clinical trial data that suggests a combination of the diabetes drugs Victoza and Tresiba is more effective than using Tresiba alone.
In preparation for an FDA advisory panel meeting on May 24, the reviewers released a report (PDF) that expresses concerns over the clinical trials Novo Nordisk conducted, which showed that its combination drug Xultophy, already on the market in Europe, was more effective than Tresiba alone.
Victoza (liraglutide) is an injectable diabetes drug introduced by Novo Nordisk in 2010, as a competitor to Byetta. Tresiba (insulin degludec) is a long-acting form of insulin approved last year. Together, the two are referred to as IDegLira here in the U.S., as the combination does not yet have a brand name here.
The FDA reviewers raised questions about combining the two drugs, which work very differently. One concern was that the proposed dosage of Victoza is below the dose usually considered effective when Victoza is used alone. The reviewers warned that some sensitive patients “could be exposed to one component that provides no therapeutic benefit and causes specific adverse reactions.”
“As was seen in the IDegLira program, subjects randomized to IDegLira experienced adverse events caused by both of its components, namely subjects experienced gastrointestinal adverse events (liraglutide) and hypoglycemia (insulin degludec),” the reviewers warned. “Further, the use of IDegLira allows for doses of liraglutide lower than that approved for glycemic lowering, and a patient may be exposed to a dose of liraglutide that has not been studied in phase 3 trials and determined to be efficacious while incurring safety risks associated with liraglutide use.”
They also questioned the design of the study, raising concerns that inadequate insulin dosing could have skewed the results.
The advisory panel will take the reviewers report, as well as other testimony and scientific evidence, into consideration and then recommend a course of action to the FDA. Novo Nordisk is trying to get the drug approved for the U.S. market.
The panel’s recommendations are not binding on the FDA, however, they usually factor heavily into the agency’s final decisions.
The concerns over a Victoza and Tresiba combination drug comes amid continuing concerns about the risk of pancreatic cancer, with a number of Victoza lawsuits pending in courts nationwide on behalf of former users who allege that Novo Nordisk failed to adequately warn consumers and the medical community. Similar allegations have been raised in claims involving other diabetes drugs from the same class of medications, including Byetta lawsuits, Januvia lawsuits and Janumet lawsuits, alleging that the entire incretin mimetic class of drugs increases the risk of pancreatic cancer for diabetics.