U.S. pharmaceutical corporation Pfizer has filed a lawsuit against Indian drug maker Torrent Pharmaceuticals Ltd. in an effort to prevent sales of a generic version of its erectile dysfunction treatment product Viagra.
In legal documents filed in a federal court in Manhattan, Pfizer claimed that the Indian manufacturer has applied with the U.S. Food and Drug Administration (FDA) for approval of its product known as sildenafil citrate before Viagra's patent expiry date in October 2019. Pfizer is seeking a permanent ban on Torrent to make, sell, market, distribute or import sildenafil citrate, as it infringes patent regulations, media reports have said.
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Viagra is one of Pfizer's most popular products and accounts for a sizeable proportion of the company's revenue. Figures provided by Bloomberg show that in 2013 Viagra sales came in at $1.88 billion, or about 3.6 percent of Pfizer's total revenue. Other companies have also been pursued in court over attempts to infringe Viagra's patent on previous occasions.
The United States is a key market for Pfizer's blockbuster drug, as its patent has now expired in Europe, Korea and other parts of the world. Pfizer has already lost the patent on another one of its best-selling products, Lipitor, and generic versions of the product used to reduce high cholesterol levels are rapidly gaining ground in the United States.
