* Says FDA did not grant orphan status to Levulan therapy
* Levulan developed for prevention of skin cancer
* Co plans to close its SOTR clinical program
* Shares plunge 18 pct
Aug 6 (Reuters) - DUSA Pharmaceuticals Inc DUSA.O said it was planning to stop a mid-stage trial of its therapy to help prevent a type of skin cancer in organ transplant patients after the U.S. health regulator refused to grant orphan drug status to the treatment.
Shares of the company fell as much as 18 percent to $2.07 after the announcement, but pared some losses to trade at $2.37 in afternoon trade Friday on Nasdaq.
The U.S. Food and Drug Administration grants orphan status to drugs that may provide a significant therapeutic advantage over existing treatments and target conditions affecting 200,000 or fewer patients in the United States every year.
It grants the drugmakers marketing exclusivity of seven years in the United States, upon approval.
The company said the FDA did not give orphan drug designation to its Levulan photodynamic therapy for the prevention of cutaneous squamous cell carcinomas (SCCs) -- a form of skin cancer -- in patients who have a proven history of multiple localized cutaneous SCCs over a 12 month period.
Solid organ transplant recipients are at greater risk of contracting infections and cancer as they are kept on immunosuppressive agents.
"Without the regulatory protection and development opportunities that orphan drug designation affords our resources are better utilized in other areas, therefore, we plan to close out our SOTR (solid organ transplant recipients) pilot clinical trial program over the next few months," Chief Executive Robert Doman said.
In May 2009, the company initiated a mid-stage trial for the treatment of skin cancers in SOTRs. (Reporting by Krishnakali Sengupta and Anand Basu in Bangalore; Editing by Aradhana Aravindan)