* Says fidaxomicin shows non-inferiority to Vancocin
* Says to use data to support marketing application
* Says drug was well tolerated
* Shares up as much as 20 pct post-market (Adds conference calls details)
BANGALORE, Feb 4 (Reuters) - Drug developer Optimer Pharmaceuticals Inc OPTR.O said its experimental antibiotic pill fidaxomicin met the main goal of a second late-stage study, sending its shares up as much as 20 percent after the bell.
In the late-stage study, fidaxomicin proved to be as efficacious as existing standard of care Vancocin in treating clostridium difficile infection -- a bacterial infection in the gut.
Optimer, which plans to use data from the second study to support its marketing application for the drug, said on a conference call with analysts that it would seek priority review of the product.
The company said it would file for the marketing application with the U.S. Food and Drug Administration in the second half of 2010.
"In terms of partnering, there is really no color to add there. Discussions are ongoing," Chief Financial Officer John Prunty said on the call.
In August 2009, the company said it was in talks with potential partners to market the drug outside the United States. [ID:nWNBB6956]
The drug, which had already met the main goal of an earlier late-stage study in November 2008, was well tolerated in the second study.
Fidaxomicin also had significantly lower recurrence rates and higher cure rates without recurrence within four weeks of completing therapy, compared to Vancocin.
Shares of the San Diego, California-based company jumped 20 percent to $14.25 after the bell. They closed at $11.86 Thursday on Nasdaq. (Reporting by Vidya L Nathan in Bangalore; Editing by Anne Pallivathuckal)