Expanded Indication for Byetta to Include Monotherapy for Glucose Control

The updated warning label includes a pancreatitis caution, including nonfatal hemorrhagic or necrotizing pancreatitis, and an expansion of an existing warning for patients with renal impairment. The new indication was based on a clinical study of 232 patients unable to achieve glycemic control through diet and exercise alone.

Those enrolled reduced blood sugar over three months by 0.7% and 0.9% with 5 mcg and 10 mcg dosages respectively versus placebo. Patients lost an average of around 6 pounds between exenatide groups.

Although the updated label warns of pancreatitis, a recent study found the disease was not more common in exenatide than in other Type 2 diabetes drugs.  Aditional side effects include severe allergic reactions, nausea, vomiting, diarrhea, dizziness, headache, jitters, and acidic stomach.

Orville G. Kolterman, M.D., senior vice president of research and development, Amylin Pharmaceuticals, stated that, "The current label reflects our understanding of post-marketing reports of renal events and provides physicians with updated guidance about appropriate use in patients with renal conditions. There is no evidence from preclinical and clinical studies that BYETTA has any direct toxic effect on the kidney.... Post-marketing reports of serious changes in renal function have been rare and usually complicated by other factors that could have contributed to the kidney problems. It is also important to note that diabetes is the leading cause of kidney failure." Information about use of BYETTA in patients with impaired renal function was included in the initial product label in 2005 and was updated in 2007.

In addition to the monotherapy indication, the FDA approved changes to the BYETTA Prescribing Information to incorporate updated safety information. The new label expands upon existing language regarding use of BYETTA in patients with renal impairment, which Amylin and Lilly updated in September 2007 to include additional language regarding renal adverse events. It specifies that BYETTA should not be used in patients with severe renal impairment or end-stage renal disease and should be used with caution in patients with renal transplantation. It also specifies that because BYETTA may induce nausea and vomiting with transient hypovolemia (low blood volume), treatment may worsen renal function.