SEATTLE (AP) -- Drug developer Omeros said Tuesday it received clearance to study its experimental eye-surgery drug OMS302 in children.

Omeros said the Food and Drug Administration's decision could give it an extra six months of marketing exclusivity in the U.S., meaning similar products would be barred from the market. European Union regulators approved a similar plan in July. Omeros said it will start pediatric studies of the drug in 2014.

OMS302 is a combination of two topical medications that are used in lens replacement surgeries for cataracts and other conditions. One component causes pupil dilation and the other is an anti-inflammatory drug intended to reduce pain and irritation after surgery. Regulators in the U.S. and EU are reviewing OMS302 and Omeros hopes to launch the drug next year. Results from the pediatric studies wouldn't be available until after regulators rule on the drug.

Omeros Corp. doesn't have any approved drugs, and OMS302 is its most advanced experimental product.

Shares of Omeros added 65 cents, or 5.6 percent, to $12.18 in Tuesday morning trading. The stock has more than doubled in value since Sept. 13 as analysts took positive views of the drug and regulators started their reviews.