Analyzing whether proof of conception of a DNA segment invention required a showing of the entire polynucleotide sequence, the U. S. Court of Appeals for the Federal Circuit affirmed the Board of Patent Appeals and Interferences (currently known as the Patent Trial and Appeals Board and hereafter Board), finding that Pfizer, the junior party to the interference, was entitled to priority of the invention.  Sanofi-Aventis v Pfizer Inc., Case No. 12-1345 (Fed. Cir., Nov. 5, 2013) (Newman, J.).

As the junior party to the interference, Pfizer needed to demonstrate earlier conception of the invention and diligent reduction to practice.  The invention was directed to an isolated protein comprising certain amino acids or to the complementary DNA (cDNA) which coded for that protein.  The count at issue (i.e., the invention used for the priority determination) was defined as the following two alternatives:  the isolated protein comprising the amino acid sequence of SEQ ID NO:4, or an isolated polynucleotide comprising a nucleotide sequence of SEQ ID NO:3 from nucleotide 103 to nucleotide 1242.

The central issue in the interference was whether Pfizer had sufficient information concerning the cDNA to show it was in possession of, and thus had a complete conception of, the claimed cDNA at a date earlier than Sanofi-Aventis.  Sanofi argued that the standard for conception of a claim to cDNA required a showing that Pfizer had accurately determined the entire polynucleotide sequence of the claimed cDNA, and that Pfizer did not have a completely accurate analysis of the entire nucleotide sequence prior to Sanofi’s conception date due to sequencing errors in its analysis at the time.  Pfizer later corrected its analysis and accurately described the entire cDNA sequence but after Sanofi’s conception date. 

Pfizer had presented evidence that it had isolated the cDNA and had some additional information about the cDNA including at least a partial sequence.  Under the facts of the case, the Board ruled that Pfizer established earlier conception and actual reduction to practice of the count.  Sanofi appealed. 

The Federal Circuit affirmed, explaining that when the subject matter is a DNA segment, conception requires possession and appreciation of the claimed DNA segment.  The Court further explained that possession can be shown by ways other than identifying the actual sequence of the DNA such as by describing characteristics sufficient to identify the DNA segment and how to obtain it.

Practice Note:  Although the America Invents Act (AIA) obviated patent interferences, interferences are likely to continue for several years as are derivation proceedings under the AIA.  Thus it is advisable to maintain records that may help to establish possession of invention, e.g., documents describing characteristics of the claimed subject matter, for U.S. patents and applications filed prior to AIA and even afterwards.