Victoza Report Raises Byetta Safety QuestionsJun 7, 2011 | Parker Waichman LLP
A new report from the Institute for Safe Medicine Practices (ISMP) may raise safety concerns about a new generation of diabetes drugs, including Byetta. While the group’s new QuarterWatch report discusses another drug called Victoza and pancreatitis, the ISMP raises concerns that similar diabetes medications may also pose an elevated risk of pancreatitis.
Both Byetta and Victoza are injectable medications that act on glucagon-like-peptide-1 (GLP-1), a hormone in the digestive tract that impacts glucose levels. Two other diabetes drugs, Januvia and Onglyza, both oral medications, also act on GLP-1, though via a different mechanism.
According to the ISMP, pre-approval testing for diabetes drugs is simply too short to determine their risk-benefit profile. However, the U.S. Food & Drug Administration (FDA) fears that if long-term testing were required of such drugs, pharmaceutical companies would stop developing them because of cost concerns.
According to its latest QuarterWatch report, the January 2010 approval of Victoza was controversial at the FDA because of uncertainty about its cardiovascular risks, and animal studies showing an increased risk of thyroid cancer. At the time of its approval, it was mandated that the Victoza prescribing information include a Black Box Warning about thyroid cancer risk. The FDA also stipulated that it only be used as a second-line treatment, meaning other drugs should be preferred.
When it approved Victoza, the FDA expressed hope that the second-line status would mean that it would be slowly adopted into clinical practice. But despite the safety concerns surrounding Victoza, it has become widely used since its approval, with over 200,000 prescriptions dispensed in the first nine months after its approval. Meanwhile, the ISMP asserts that it will be years before the true risk-benefit profile of Victoza can be known.
The ISMP's analysis of the FDA's Adverse Event Reporting database found that Victoza accounted for 70 cases of acute and chronic pancreatitis – a risk factor for pancreatic cancer - in the third quarter of 2010, and 105 cases since approval nine months earlier. Only Byetta, with 78, was the subject of more pancreatitis reports. Januvia was named in 18 reports and Onglyza with 14.
The ISMP report states: "It appeared that the two injectable GLP-1 analogs (Victoza and Byetta) were triggering far more reports of pancreatitis than the oral products with a different mechanism." Unfortunately, according to the ISMP, “studies to determine the incidence, identify differences between drugs and provide the basis to weigh these risks against possible benefits have not been performed."