UPDATE 2-US FDA OKs AstraZeneca, Pozen pain drug

* Agency clears drug for U.S. market

* Vimovo includes naproxen and Nexium ingredient

* Pozen shares up more than 21 percent after-hours (Adds details on approved use)

WASHINGTON, April 30 (Reuters) - The U.S. Food and Drug Administration has approved AstraZeneca Plc AZN.L and Pozen Inc's POZN.O pain drug Vimovo, an agency spokeswoman told Reuters on Friday.

Vimovo is a fixed-dose combination of the anti-inflammatory drug naproxen and an immediate release version of esomeprazole, the active ingredient in AstraZeneca’s acid reflux treatment Nexium.

FDA spokeswoman Elaine Gansz Bobo said the agency approved the drug for relieving symptoms of osteoarthritis, rheumatoid arthritis, and a type of spinal arthritis called ankylosing spondylitis. It also was cleared for decreasing the chances of gastric ulcers in patients at risk of developing them from use of pain relievers known as nonsteroidal anti-inflammatory drugs, or NSAIDs.

Shares of Pozen were up more than 21 percent, or about $2.30, in after-hours trading on Friday, trading at $13.15, after earlier closing at $10.85. (Reporting by Susan Heavey; additional reporting by Ben Hirschler in London and Vidya Loganathan in Bangalore; editing by Carol Bishopric, Bernard Orr)