Pfizer recently received an adverse determination of the patentability of one patent (of several) for Lipitor. The “Patent Baristas”1 reported that Lipitor is set to become the worlds first $10 billion a year drug.

The adverse decision was made regarding an issued patent in response to an ex parte reexamination request. Such a request can be filed at any time during the enforceability of the patent. Technically the request can be filed the term of the patent plus the 6 year statute of limitations for filing suit for infringement.

Reexamination may be requested solely on written prior art consisting of patents or printed publications. The request must explain how the cited prior art has a bearing upon the patentability of any claim of the patent. The determination regarding the adequacy of the prior art is made by the Technical Center that was responsible for the original grant of patent. Reexamination is ordered where there is a substantial new question of patentability. Again, the request for reexamination should clearly demonstrate the existence of a substantial new question of patentability.

The USPTO has 3 months after filing of a complete request to determine whether there exists a substantial new question of patentability. No input from the patent owner is considered in making this determination.

If reexamination is ordered, the patent owner has 2 months to file a written response, including any narrowing amendment of the claims. The party requesting reexamination has 2 months to file a response to the patent owner’s response.

After the statements of both parties are received, the reexamination occurs “with special dispatch”. The product is an ex parte reexamination certificated. The patent owner has 30 days to respond to the Office action.

1 Patent Baristas