Lilly and Amylin Pharmaceuticals are saying there have been four deaths among patients with pancreatitis who took their Byetta diabetes drug, in addition to the two deaths reported last week by the FDA.

Amylin says the four cases were not captured by the FDA, which received six reports of patients who developed hemorrhagic or necrotizing pancreatitis that required hospitalization. Two of those died. The additional four cases reported today did not involve patients with the necrotizing form of the disease, which affects 15 percent to 20 percent of patients with inflammation of the pancreas.

“It appears the FDA focused on necrotizing and hemorrhagic pancreatitis, whereas these other four cases only had pancreatitis in their history,” Orville Kolterman, Amylin’s senior vice president of research and development, tells Reuters.

In the necrotizing form of pancreatitis, enzymes digest the pancreas, which can lead to a hemorrhage. However, Kolterman says the deaths were not considered related to the pancreatitis. Even so, he said the company was reporting them “in the interests of transparency.”

The prescribing information for Byetta, which has been taken by an estimated 1 million patients, was updated to include the risk of pancreatitis last October. The FDA cited 30 reports of pancreatitis in Byetta patients and said the drug was suspected in some cases. One of the four deaths reported on Tuesday was known at that time, Kolterman says.

News of the deaths that were reported by the FDA on Aug. 18 sent Amylin’s shares down 13 percent, and investors questioned the company’s failure to issue a news release or hold a conference call to discuss it. Now, Amylin says it is providing all info possible to ensure patients are not confused by what they read and that future cases of pancreatitis are not necessarily interpreted as being related to treatment with Byetta.

Kolterman adds they don’t expect any link to Byetta LAR, a once-weekly updated formulation that Wall Street is excited about. He says no cases of pancreatititis have been seen in patients being tested with the new version.