Shionogi and Duchesnay add new patents to Osphena dispute
Pharmaceutical companies Shionogi and Duchesnay have filed a second lawsuit against Hetero labs, claiming that the company infringed two additional patents related to Osphena (Ospemifene)—a treatment for vaginal pain during sex.
India’s Hetero Labs filed an Abbreviated New Drug Application (ANDA) with the Food and Drug Administration (FDA) to create a generic of Osphena and market it in the US prior to the expiration of the related patents.
As part of the application process, Hetero labs sent letters to Duchesnay, notifying its intent to create an Osphen generic and claiming that the underlying patents were unenforceable.
Upon receiving the first notice letter, Duchesnay and Shionogi filed a suit against Hetero on April 14.
Now, the companies have filed a second complaint with the US District Court for the District of Delaware after receiving a second notice.
The second notice claims that US patents 6,245,819 and 8,236,861 are invalid, unenforceable, or would not be infringed by Hetero’s generic.
The ‘819 and ‘861 patents are both assigned to Michigan’s Quatrx Pharmaceuticals. Shionogi and Duchesnay are exclusive licensees for the two patents in the US.
Shionogi and Duchesnay are seeking a declaration of validity for both patents and that Hetero’s proposed generic product will infringe them. It is also seeking a preliminary or permanent injunction to bar Hetero from obtaining an ANDA until the expiration of the patents.
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