New Delhi: DUSA Pharmaceuticals, a unit of Sun Pharmaceutical Industries, has filed a trade secret misappropriation and tortious interference claim against Biofrontera Inc. in the district court of Massachusetts, the company said in a statement.

The lawsuit alleges patent violation of topical solution Levulan, and Kerastick. DUSA has also alleged that the Germany-based Biofrontera improperly obtained confidential information from former employees.

The lawsuit seeks an assessment of both damages and injunctive relief against the Biofrontera defendants. The patents-in-suit concern an apparatus and method for “photodynamic therapy" (or “PDT") and equipment for PDT. The photodynamic therapy, pioneered by DUSA, combines a drug with a light source to treat disease conditions.

The product was launched by DUSA, in September 2000 in the US. DUSA’s Levulan combination therapy is approved by FDA for treatment of non-hyperkeratotic actinic keratoses or AKs of the face or scalp.