UPDATE 2-Zogenix's pain drug meets main goal in key study

* Zohydro shows improvement over placebo

* Two secondary goals also met

* Co plans to submit marketing application by early 2012

* Shares up 7 percent (Adds analyst comments, share movement)

Aug 17 (Reuters) - Specialty pharmaceutical company Zogenix Inc said its chronic pain drug met the main goal of a late-stage study, sending its shares up as much as 7 percent.

The drug, Zohydro, is being tested as a treatment for moderate to severe chronic pain in patients who require round-the-clock opiod therapy.

The extended release capsules significantly improved chronic pain relief when compared to a placebo, Zogenix said in a statement.

Oppenheimer & Co analyst Christopher Holterhoff said although the company did not release the full data, the topline results were positive.

The adverse events -- constipation, nausea and urinary tract infection -- are also relatively minor, he added.

Two key secondary goals -- the number of patients who say at least 30 percent improvement in pain and improvement of overall satisfaction of medication -- were also met.

The company said it plans to file marketing application for Zohydro by early 2012.

The results show the company is on track to get possible drug approval in 2013, Holterhoff said.

Zogenix's shares rose 7 percent to a week's high of $4.37 in early trade on Wednesday on Nasdaq. (Reporting by Shravya Jain in Bangalore; Editing by Maju Samuel)