USPTO confirms validity of DUSA's key Levulan PDT patent

All Claims Upheld at Conclusion of Successful Reexamination Process

DUSA Pharmaceuticals, Inc.^® (NASDAQ GM: DUSA), a dermatology company that is developing and marketing Levulan^® Photodynamic Therapy (PDT), today announced that the United States Patent and Trademark Office (USPTO) has completed its re-examination of US Patent No. 5,079,262, "Method of detection and treatment of malignant and non-malignant lesions utilizing 5-aminolevulinic acid."  In its latest communication, the USPTO issued a Notice of Intent to Issue Ex Parte Re-examination Certificate which affirms the patent's original seven claims and adds eight claims.   This patent covers the use of aminolevulinic acid, the active ingredient in DUSA's Levulan^® Kerastick^®, for the treatment of actinic keratoses with light.  This patent will expire on September 30, 2013.  Additional patents cover DUSA's Levulan^® Kerastick^® formulation of aminolevulinic acid HCl in conjunction with its proprietary blue light technology until June 2019.

Robert F. Doman, DUSA's President and CEO, said, "We are pleased that the Patent Office has confirmed the validity of one of our key Levulan PDT patents.  DUSA placed this patent into reexamination at the patent office as part of our ongoing strategy to proactively strengthen the patent portfolio covering our Levulan^® PDT technology."  Mr. Doman continued, "The successful affirmation of our existing patent claims and the addition of eight new claims, along with the recent issuance of US Patent No. 7,723,910 further validates our intellectual property protection strategy for Levulan^® PDT."