The U.S. Food and Drug Administration approved Trulicity, a once-a-week subcutaneous injection to improve blood sugar levels, along with diet and exercise, in adults with type 2 diabetes, The Food and Drug Administration said on Friday.

Type 2 diabetes affects about 26 million people and accounts for over 90 percent of diabetes cases diagnosed in the United States. Over time, high blood sugar levels can increase the risk for serious complications, including blindness, heart disease, and nerve and kidney damage.

"Type 2 diabetes is a serious chronic condition that causes blood glucose levels to rise higher than normal," said Mary Parks, M.D., deputy director of the Office of Drug Evaluation II in the FDA's Center for Drug Evaluation and Research. "Trulicity is a new treatment option, which can be used alone or added to existing treatment regimens to control blood sugar levels in the overall management of type 2 diabetes."

The drug is part of a new class of medicines called GLP-1 agonists, which stimulate the pancreas to create extra insulin after meals. The FDA approved Trulicity for sale based on six studies where 3,342 patients showed improvements in blood sugar control. The drug will come with a warning highlighting that rats tested with Trulicity had cases of thyroid cancer, though it is unclear whether they were caused by the drug. The maker of the drug, Eli Lilly, will be required to conduct follow-up studies, according to The New York Times.

In February, Lilly said the drug was comparable to Novo Nordisk A/S' (NVO) once-daily Victoza in reducing blood sugar levels in a patient study, MarketWatch reported.