Eli Lilly and Co. and Amylin Pharmaceuticals Inc., rebuffed twice in their bid for U.S. approval of a weekly diabetes drug, won the backing of European Union regulators for the product.

Bydureon should be approved by the European Commission for Type 2 diabetes in adults, the London-based European Medicines Agency said Friday in a statement, following a 183-day review by its Committee for Medicinal Products for Human Use.

The drug awaits final action by the European Commission, which has the authority to approve medicines for the European Union. The Commission usually makes a decision on CHMP recommendations within two to three months.

Bydureon is a longer-acting version of the twice-daily diabetes injection Byetta sold by San Diego-based Amylin and Indianapolis-based Lilly. A weekly drug would be more convenient for patients and help the company compete with Novo Nordisk A/S, the world’s biggest insulin maker.

Amylin lost 46 percent of its market value Oct. 20 after saying the U.S. Food and Drug Administration wanted a study assessing the drug’s heart risks. The shares rose $2.24, or 20 percent, to $13.50 each overnight in premarket trading.

Byetta, a synthetic version of a substance found in the saliva of the Gila monster, stimulates pancreas cells to produce the hormone insulin when blood sugar is high. Novo Nordisk’s Victoza, which works in a similar way, can be taken once a day instead of twice. Victoza had worldwide sales of $450 million last year, Novo Nordisk said Feb. 2.

Lilly markets Byetta outside the U.S. and co-markets it with Amylin in the U.S. The drug was developed by Amylin, and the technology enabling it to be used in a longer-acting form was developed by Waltham, Mass.-based Alkermes Inc. Alkermes will receive royalties of about 8 percent on Bydureon sales.

Amylin and its marketing partners plan to submit a response to the FDA in the second half of 2011, the companies said in a March 3 statement. Shares in Amylin and Alkermes plunged that same day after a study showed Bydureon didn’t control the disease better than Victoza.