Byetta Approved for Use With TZDs

The injectable diabetes drug exenatide (brand name Byetta) has now been approved by the U.S. Food and Drug Administration (FDA) for combined use with the class of oral diabetes drugs known as thiazolidinediones.

Byetta, which was approved by the FDA in 2005, was previously indicated as an add-on therapy only for people taking the oral diabetes drug metformin (Glucophage and other names) and/or a drug from the class known as sulfonylureas (including glipizide [Glucotrol, Glucotrol XL], glyburide [DiaBeta, Glynase, Micronase], glimepiride [Amaryl], and the less commonly used chlorpropamide [Diabinese], tolazamide [Tolinase], and tolbutamide [Orinase]).

Thiazolidinediones, also known as “glitazones” or “TZDs,” work by making the body’s tissues more sensitive to insulin and by causing the liver to release less glucose into the bloodstream. The two TZDs currently on the market are pioglitazone (Actos) and rosiglitazone (Avandia).

Byetta, the first in a new class of diabetes drugs called “incretin mimetics,” stimulates insulin secretion when blood glucose levels are elevated.

A clinical trial to test combination treatment with Byetta and TZDs enrolled 233 participants with Type 2 diabetes whose blood glucose levels were not adequately controlled by their oral diabetes medicine regimens (of either a TZD alone or a TZD plus metformin). The study found that 62% of participants who added twice-daily Byetta injections to their oral medicines lowered their HbA1c levels (a measure of blood glucose control over time) to 7% or less over a period of 16 weeks. Only 16% of participants in the group that added placebo injections to its daily medicines did the same. The group that added Byetta also lost more weight than the placebo group (3.3 pounds versus 0.4 pounds) during the same period. The most common side effect of Byetta therapy was nausea, experienced by 40% of participants who received Byetta and 15% of participants who received a placebo injection.

According to a press release from Amylin Pharmaceuticals, Inc., and Eli Lilly and Company, the manufacturers of Byetta, health-care professionals will be educated about this new use for Byetta in the coming weeks.