The FDA is working on a stronger label for the widely used diabetes drug, which is marketed by Lilly and Amylin Pharmaceuticals after deaths continue to be reported despite earlier government warnings. Six new new reports were received of patients developing a dangerous form of pancreatitis while taking Byetta. Two patients died and four were recovering, the Associated Press reports.

The drugmakers said in a statement that patients taking Byetta have shown “very rare case reports of pancreatitis with complications or with a fatal outcome.” They added that diabetes patients are already at increased risk of pancreatitis compared with healthy patients.

The FDA announcement updated an October alert about 30 reports of Byetta patients developing the ailment. Regulators stressed that patients should stop taking Byetta immediately if they develop signs of acute pancreatitis, which can cause nausea, abdominal pain and potentially deadly complications. More than 700,000 patients worldwide have used the injectable drug since it was launched in June 2005.

In an investor note, Deutsche Bank analyst Barbara Ryan writes that “growth in demand for Byetta has been lackluster in the last couple of years (total prescriptions are up about 7 percent year-to-date) and this development obviously an’t help. The more important question is whether in the current regulatory environment it could impact timelines for development (of a long-acting release formulation). The occurrence of pancreatitis appears to be rare in Byetta users, but in our view, there could potentially be heightened concern regarding pancreatic complications with the longer-acting version of the drug, for which the overall patient database is still fairly small.”