Pink eye drug AzaSite, a major component of Inspire Pharmaceutical's
Inspire said in a regulatory filing that generics company Sandoz notified the company that it has submitted an application to the U.S. Food and Drug Administration seeking approval to market a generic version of AzaSite. Sandoz said in the letter that patents issued to InSite Vision and Pfizer
Inspire in 2007 was granted a license to InSite's patents, as well as a sublicense to Pfizer's patents. InSite and Pfizer each have primary responsibility for enforcing rights of their respective patents. But the agreement did give Inspire "step-in rights" to start legal action against an infringer if InSite and Pfizer don't do so first.
The companies have 45 days from receipt of the April 15 letter to start a patent infringement lawsuit against Sandoz. A suit would result in an automatic stay of FDA approval of Sandoz's generic for up to 30 months, or until a final court decision.
"If required, Inspire intends to vigorously enforce its intellectual property rights, pursuant to the step-in rights, relating to AzaSite," the company said in the filing.
AzaSite was developed to treat bacterial conjunctivitis, also known as pink eye. The drug targets the single-agent ocular antibiotic market, which was estimated to be about $576 million in the United States. In 2010, prescriptions for all branded products in this category totaled 15 million, according to data compiled from IMS Health.
AzaSite generated $42.7 million in revenue in 2010, a 22 percent increase over 2009 sales that the company attributed to a higher number of prescriptions and greater patient usage.