Patent Term Extensions: A Leap Frog of Sorts to Set Expiration Date

March 30, 2007
Post by Blog Staff

In a case before the Federal Circuit, the court affirmed the district court's decision that a patent term extension under the Hatch-Waxman Act, 35 U.S.C. § 156, may be applied to a patent subject to a terminal disclaimer under 35 U.S.C. § 253. The Federal Circuit found that the language of § 156 is unambiguous and fulfills a purpose unrelated to and not in conflict with that of § 253. As a result, even though the patentee filed a terminal disclaimer, the patent term extension still applied, extending the term of the patent 1233 days. More details of the case after the jump.The patent infringement dispute at issue began in August 2005, when Hi-Tech filed with the FDA an Abbreviated New Drug Application (ANDA) for a generic version of a drug for the treatment of ocular hypertension. As required in its application, Hi-Tech included information related to patents which included the art of the drug and also notified Merck that Hi-Tech's generic eye-drops did not infringe Merck's '413 patent. In response, Merck sued Hi-Tech for infringement of the '413 patent. Hi-Tech answered that the '413 patent expired on December 12, 2004. The question at issue was the correct expiration date of the '413 patent. The patent expiration date question arose when during the prosecution of the '413 patent, Merck overcame an obviousness-type double patenting over the claims of an earlier Merck patent (the '115 patent) filing a terminal disclaimer which disavowed any term of the '413 patent that would extend beyond June 30, 2004 – the original term of the '115 patent. The June 30, 2004, expiration date was then reset by operation of law to December 12, 2004 (twenty years after the filing date of the '115 patent) in accordance with the Uruguay Round Agreement Act (URAA) of 1994. Merck then sought an extended term of the '413 patent under § 156 based on the period of regulatory review undertaken by the FDA. Based on the patent term extension of 1233 days, the expiration date of the '413 patent thus became April 28, 2008. The question was whether the patentee's decision to submit a terminal disclaimer to avoid an obviousness-type double patenting rejection also disclaims any patent term extension to which the patentee would otherwise have been entitled under § 156. The Federal Circuit held that a term extension under § 156 is not foreclosed when a terminal disclaimer is filed under § 253. Specifically, the court noted that the patent term extension under § 156 is described in mandatory terms, stating that, if certain conditions are met, "The term of a patent . . . shall be extended in accordance with this section from the original expiration date of the patent." Because of the statute's unambiguous, mandatory nature, the court found that the existence of a terminal disclaimer did not override the extension granted by § 156, and Merck was entitled to the additional 1233 days of patent protection for the '413 patent. As a result, the court affirmed the lower court's decision finding Merck's patent still in force. To read the full opinion in Merck & Co. v. Hi-Tech Pharmacal Co., Inc., click here.

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