Multinational drug majors Pfizer and AstraZeneca have filed separate patent infringement cases against city-based Pharma Company Hetero Drugs in two different US courts.
While Pfizer dragged Hetero to court for violating patents of its blockbuster drug Viagra, which is used for the treatment of impotence, AstraZeneca filed a patent infringement suit seeking an order restraining the generic drug maker from launching a generic version of its 'Nexium' drug, which is used for the treatment of acid-related diseases, before the patent expiry.
The patents for Viagra and Nexium will expire on October 22, 2019, and August 3, 2015, respectively.
When contacted, a senior official of Hetero termed the development as routine.
"Our processes are non-infringing and have been developed for launch only after patent expiry. While it necessitates us to file Abbreviated New Drug Applications (ANDAs) before patent expiry, it is routine for the originators to challenge filings in the interim," Hetero Drugs Director (Marketing) Srinivas Reddy told PTI.
"There are many examples of filing this kind of patent suits in US where the judgement went against the plaintiffs," he added.
Pfizer filed a petition in the district court for the Southern District of New York alleging that Hetero's generic version will infringe Viagra's patent.
Hetero filed an ANDA for its generic Viagra drug with the US Food and Drug Administration on June 17.
Pfizer requested the court to issue a permanent injunction order against the Hyderabad drug-maker from selling, making or importing the generic version until the expiry of the patent for Viagra, which cloaked revenues of $1.93 billion worldwide in 2010.
According to Pfizer, Viagra worldwide revenues increased 2% in 2010, compared to 2009.
In the USA, Viagra revenues increased 3% in 2010, compared to 2009.
Viagra began facing generic competition in Spain and Finland in December, 2009.
