GlaxoSmithKline (NYSE: GSK) said it will seek regulatory approval of its experimental diabetes medicine albiglutide early next year after the drug showed a benefit in a trial.

Patients taking albiglutide, a once-weekly injection, showed a statistically significant reduction in blood sugar levels compared with Merck & Co.’s sitagliptin, London-based Glaxo said in a statement today.

The study is one of eight for the drug and the last required to complete the approval registration package, said Glaxo, which maintains its U.S. headquarters in Research Triangle Park.

“A meta-analysis which demonstrates that a therapy will not result in an unacceptable increase in cardiovascular risk is required by the FDA for the registration and approval of any product for the treatment of type 2 diabetes in the U.S.,” GSK said in a statement. “The EMA [European medicines Agency] has announced a similar safety assessment requirement for such treatments.

“For the albiglutide meta-analysis, an independent clinical endpoints committee adjudicated cardiovascular events across all eight Phase III Harmony studies involving approximately 5,000 patients and from one Phase II study. This analysis has now been completed and rules out excess cardiovascular risk according to a threshold pre-specified by the FDA. Analyses of the data support progression to submission and will be presented to health authorities in the coming months.”

GSK noted that it “is developing albiglutide as a once-weekly injection using a pen injector to allow reconstitution by the patient and a fine gauge needle for subcutaneous administration.”

GSK’s diabetes drug Avandia, once a blockbuster in sales, ended up being pulled from the market due in part to links to heart attacks in patients. In February, GSK agreed to settle some 20,000 lawsuits.

In 2010, the U.S. Food and Drug Administration and the European Medicines Agency both issued new guidelines strictly limiting the drug.

Avandia was suspended in Europe and allowed in the United States only with stronger warnings about the risks, restrictions that all but quashed the drug’s commercial viability.

GSK last November reached a deal with the U.S. government regarding illegal marketing of Avandia and other drugs. The settlement calls for the drugmaker to pay $3 billion to settle criminal and civil claims. That settlement was formalized last week.

Albiglutide, along with the lupus treatment Benlysta and darapladib for heart disease, form a trio of drugs Glaxo has developed with Human Genome Sciences Inc. If approved, the product would compete with existing medicines from Amylin Pharmaceuticals Inc. and Novo Nordisk A/S, as well as other experimental drugs being developed by Sanofi and Eli Lilly & Co.

(Bloomberg news contributed to this report.)