In Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc. (March 7, 2008), the Federal Circuit reversed a decision of the U.S. District Court for the District of New Jersey holding that claims 1-4 and 11-17 of U.S. Patent No. 5,760,068 (“the ‘068 patent”) were not invalid for obviousness-type double patenting.
On November 20, 1993, Pfizer filed U.S. Patent Application No. 08/160,594 claiming a broad range of chemical compounds that would selectively inhibit COX-2. The application included claims directed to the chemical compounds, to compositions using the chemical compounds, and to methods of using the chemical compounds. The examiner issued a restriction requirement, identifying the chemical compounds, the compositions using the chemical compounds, and the methods of using the chemical compounds as separate inventions. In response, Pfizer restricted the application to the generic compound claims and, within that genus, elected the single compound species celecoxib for prosecution on the merits should the generic claim be found unpatentable. The ‘594 application ultimately issued as U.S. Patent No. 5,466,823 (“the ‘823 patent”). Subsequent to the restriction requirement, Pfizer filed a divisional application that included the restricted-out composition claims and which ultimately issued as U.S. Patent No. 5,563,165 (“the ‘165 patent”). Pfizer also filed a continuation-in-part application (“CIP”) that included the restricted-out method claims and which ultimately issued as the ‘068 patent. There was an intervening CIP between the application which issued as the ‘823 patent and the CIP which issued as the ‘068 patent.
The Federal Circuit disagreed with the district court’s position that the ‘165 patent could not serve as prior art against the ‘068 patent because of the safe-harbor provision of 35 USC 121 as well as with Pfizer’s arguments that the terms CIP and divisional application are merely labels of administrative convenience. The Federal Circuit held that the safe-harbor provision of section 121 strictly applies to divisional applications. The Federal Circuit noted that a CIP is different from a divisional application because it contains new matter whereas a divisional application does not. The Federal Circuit noted that the drafters of section 121 omitted CIPs from section 121 even though they were aware of the difference between CIPs and divisional applications.
35 USC 121 — If two or more independent and distinct inventions are claimed in one application, the Director may require the application to be restricted to one of the inventions. If the other invention is made the subject of a divisional application which complies with the requirements of section 120 it shall be entitled to the benefit of the filing date of the original application. A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application. The validity of a patent shall not be questioned for failure of the Director to require the application to be restricted to one invention.