I don’t usually write about district court decisions, but the patent indefiniteness ruling in Andrulis Pharmaceuticals Corp. v. Celgene Corp. (D. Del., July 26, 2015), caught my attention. The court held the asserted claim indefinite based on the term “enhanced,” not because it was a qualitative term, but because “it could mean less than additive, additive, or greater than additive.” Did the Applicant’s cautious language during prosecution lead to the court’s finding? 

The Patent At Issue

The patent at issue was Andrulis’s U.S. Patent 6,140,346, and claim 2 was the asserted claim:

2. A method for the treatment of neoplastic diseases in a mammal which comprises administering to said afflicted mammal enhanced therapeutically-effective amounts of thalidomide in combination with effective amounts of other alkylating agent selected from the group consisting of mechlorethamine, cyclophosphamide, ifosamide, melphalan, chlorambucil, busulfan, thiotepa, carmustine, lomustin, cisplatin, and carboplatin wherein said neoplastic diseases are sensitive to said enhanced combination.

According to the district court’s claim construction order, Andrulis argued that the term “enhanced” meant “synergistic,” and noted that the term was introduced “during prosecution in response to an examiner advising that claims concerning drug combinations ‘directed to a showing of greater than additive effect’ would overcome prior art.” Celgene argued that the term was indefinite, noting that “the patent never defines whether the claimed enhancement is less than additive, additive, or greater than additive.”

The Prosecution History

The district court summarized the prosecution history as follows:

It is true that the examiner told the applicant during prosecution that claims showing a “greater than the additive effect” would overcome a particular piece of prior art, Liversidge et. al. …. The applicant in response did add “enhanced” to the patent claims, implying that term would overcome the Liversidge prior art–but that does not mean enhanced is the same as “greater than additive.” …. The fact that the applicant used “enhanced” rather than “greater than additive” suggests that the applicant chose not to expressly adopt the examiner’s  position, as the applicant could have easily used the examiner’s suggested language. The applicant did not expressly say what was meant by “enhanced.” Based on common usage alone, it would seem that the applicant opted for “enhanced” because it was broader than “greater than additive.”

Or because the term “enhanced” is used in the specification, while the terms “additive” and “synergistic” are not …. 

The prosecution history demonstrates that the applicant did not simply adopt the examiner’s position that the claims require a greater than additive effect. This point becomes more clear when the next paragraph of the applicant’s response is examined, where the applicant “vigorously disagree[ d]” with the examiner’s reliance on the Liversidge prior art: “Applicants vigorously disagree with the assertion in the Office Action stating that one skilled in the art would reasonably expect to arrive at the compositions and method of the present invention. The Office has failed to show where in Liversidge et al. there is a teaching or suggestion of the use of thalidomide in combination with other anticancer agents.” ….

If the Liversidge prior art did not teach this combination, then the applicant did not need to overcome the rejection by amending the claims to have a greater than additive effect. Adding “enhanced” might make the claims different, but the new term, at least according to the applicant’s position, does not really relate to whether or not the claims now require a greater than additive (or some other) effect. The applicant did not merely adopt the examiner’s position on Liversidge but disagreed with it. Therefore, Plaintiff cannot simply state that the applicant used “enhanced” to adopt the examiner’s position on “greater than additive.” It cannot be the case that “enhanced” is merely a synonym for “greater than additive” when read within the context of the examiner’s rejection, and the applicant’s amendment and response.

The district court dismissed the inventor’s testimony as to the meaning of “enhanced” as largely irrelevant,  and held the term indefinite under the standard set forth in Nautilus, Inc. v. Biosig Instruments (U.S. 2014) “because it does not inform a person skilled in art of the invention with reasonable certainty of its meaning in the patent-in-suit.”

Enhanced Scrutiny Of Prosecution History?

If this decision has any lessons for practitioners, it is a striking reminder of how every statement made during prosecution “can and will be used against you in a court of law.” Many practitioners routinely argue against rejections even if they are presenting claim amendments that should satisfy the examiner. While sometime such arguments can be valuable–or at least harmless–this case illustrates why they always warrant a second thought.