DUSA Pharmaceuticals Inc has filed the claims "in an ongoing patent infringement lawsuit against Biofrontera Inc, Biofrontera Bioscience GmbH, Biofrontera Pharma GmbH, and Biofrontera AG in the United States District Court for the District of Massachusetts", Sun Pharmaceutical Industries said in a statement.
The lawsuit alleges patent infringement of DUSA's patents covering a product, Levulan Kerastic (aminolevulinic acid HCl), for topical solution 20 per cent used with its BLU-U blue light photodynamic therapy illuminator, it added.
The product is indicated for the treatment of minimally to moderately thick actinic keratoses of the face or scalp.
"In its amended complaint, DUSA additionally alleges that the Biofrontera defendants misappropriated confidential and trade secret information from DUSA and improperly obtained confidential DUSA information from former DUSA employees to sell and market defendants' own products," Sun Pharma said.
The lawsuit seeks an assessment of both damages and injunctive relief against the Biofrontera defendants, it added.
The patents-in-suit concern an apparatus and method for 'photodynamic therapy' and equipment for the therapy, Sun Pharma said.
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, it added.
Sun Pharma stock closed 0.28 per cent down at Rs 560.80 on BSE.
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