Bausch + Lomb has bought the assets and U.S. rights for Zirgan from Sirion Therapeutics. Zirgan is a topical anti-viral used to treat acute herpetic keratitis, or corneal ulcers, a condition that often results in corneal transplants. It is caused by the herpes simplex virus, and recurs repeatedly, leading to scarring and inflammation that can cause blindness. Ganciclovir gel, which is what Zirgan is, has been used in Europe for over a decade under the trade name Virgan, sold by Laboratoires Théa of France. In 2007, Sirion Therapeutics acquired a license for the Zirgan product technology and trademark from Théa for the U.S. market. The drug was approved for use in the U.S. in 2009. Sirion introduced Zirgan to the U.S. market earlier this year, representing the first innovation in ocular anti-viral therapy in the U.S. in more than 30 years.