The U.S. District Court for the District of Columbia overturned a decision by the Board of Patent Appeals and Interferences (the Board) of the U.S. Patent and Trademark Office (USPTO), affirming an examiner’s refusal to grant a reexamination certificate because the patent’s claims were allegedly invalid for obviousness-type double patenting. Takeda Pharmaceuticals Co., LTD., v. Dudas, Civ. No. 06-1640 (D.D.C., Sept. 18, 2007) (Hogan, C.J.).

Issued in 1996, U.S. Patent No. 5,583,216 (the ’216 patent) claims priority back to 1974. The second patent in this priority chain, U.S. Patent No. 4,298,606 (the ’606 patent), claims chemicals referred to as cephem products and discloses methods for making them. It was not until 1990 that Takeda actually filed claims directed to the methods, which ultimately issued in the ’216 patent. In 1998, an anonymous third party requested reexamination of the ‘216 patent, alleging that cephem product claims of the ’606 patent rendered the process claims of the ’216 patent invalid for obviousness-type patenting. The examiner agreed, and the Board upheld the decision on the grounds that the process claimed in the ’216 patent was disclosed in the ’606 patent and that the process claims of the ‘216 patent were patentably indistinct from the ’606 patent’s product claims because there were no credible alternative methods for making cephem products. The Board also faulted Takeda for the 15-year delay in presenting the method claims.

On appeal, Takeda argued that process claims of the ’216 patent and product claims of the ’606 patent were patentably distinct because alternative methods exist for making the cephem products. Takeda sought to introduce a declaration (the Duggan declaration) that disclosed such alternate methods for making cephem products. The USPTO did not dispute the substance of the Duggan declaration, but rather sought to have it excluded for not having been provided to the Board previously and for raising new issues. The Court disagreed, noting that it was long-settled case law that an appeal from the Board to a district court, as opposed to the Federal Circuit, allowed applicants to introduce new evidence. The USPTO also argued that, even if considered, the Duggan declaration is irrelevant because the alternate cephem synthesis methods described in the Duggan declaration were not known at the time of filing of the ’216 patent. The Court concluded that courts may look at evidence arising after the date of filing when conducting a double-patenting analysis. As such, the Duggan declaration was proper and relevant to the issue of obviousness-type double patenting. The Court cited Federal Circuit case law for the proposition that, where a patented product can be made by a process other than the patented process, no double-patenting exists between the two. The Court also noted that it failed to find any case law supporting a theory that Takeda’s 15-year delay in filing the process claims of the ’216 patent should render such claims invalid for obviousness-type double patenting. The Court granted summary judgment, ordering the USPTO to issue a reexamination certificate.