Gilead Sciences, a California based bio-pharmaceutical research firm, and its patent partner, Roche Holding AG, have sued Indian generic drug maker Natco Pharma for allegedly infringing a US patent for Tamiflu, a drug used in treatment of bird and swine-flu infections. Tamiflu (Oseltamivir phosphate) was developed by Gilead, and receives royalties on the drug’s sale from Roche Holding AG. Gilead has requested a federal court in Wilmington, Delaware, to block generic versions of Tamiflu until its patent expires in 2017.
In February, Natco had filed an abbreviated new drug application (ANDA) with the US Food and Drug Administration (FDA) under Para-IV and alleged Gilead’s patent on the drug was invalid and sent a notice to Gilead to that extent.
Natco was the first company to file an application with the US FDA for the generic version of Tamiflu and may be entitled to 180 days of generic market exclusivity after approval.
According to reports, the revenues from Tamiflu clocked global annual sales in the region of $1 billion.
The company has tied up with Luxemburg-based Alvogen IPCO S.A.R.L., for marketing and sale of Oseltamivir phosphate in the USA.
Gilead has the basic patent rights of Oseltamivir phosphate until August 2, 2016.
Natco shares were being traded at Rs 252 on the Bombay Stock Exchange today.