CAFC Re-considers Disclaimer Based Intervening Rights Defense

During a post grant proceeding, an amendment of an originally issued claim could create an intervening rights defense for potential  infringers. That is to say if the amended or new claim introduced by the post grant proceeding is not substantially identical in scope relative to a previously issued claim, potential infringers of the amended/new claims may be provided with an absolute and/or equitable intervening rights defense (35 USC § 252). Whether or not a claim change in post grant patent proceeding results in the an intervening rights defense is far from a straightforward determination as evidenced by the recent decision Marine Polymer Technologies, Inc. v. Hemcon, Inc..

The earlier panel ruled that disclaimer of claim scope is equally effective in creating an intervening rights defense as an explicit amendment. As such, the decision may be distorted to suggest that even if the patent owner is merely urging a claim interpretation that is consistent with the manner in which the term would have been understood at the time the underlying patent application was filed, intervening rights are created  For example, in cases where the post grant record simply clarifies the way in which a skilled artisan would have understood a claim term at the time of filing, or reiterates the positions of the previous intrinsic record, the scope of the claims cannot properly be said to have been altered during the subsequent proceeding.

Will the en banc ruling provide for such needed flexibility?

Post grant PTO patent proceedings often focus on the meaning of different aspects of originally issued claim language than were considered during the earlier application prosecution.  Therefore, much of the argument made by the patent owner during the subsequent PTO proceeding is directed to new issues not previously considered by the PTO.  It is to be expected that re-opening the intrinsic record via post grant file histories will often include substantively new discussion of various claim terms.

Moreover, in post grant proceedings patent claims are accorded the broadest reasonable interpretation (“BRI”).  Determining the BRI requires a different analysis than carried out in a district court during claim construction, and notably, there is no requirement that the PTO consider the earlier prosecution record in ascertaining the BRI and meaning of an originally issued patent claim.  This often places patent owners in the position of having to re-argue distinctions which were implicitly or explicitly accepted by the previous patent examiner.  When the PTO requires amendment of a claim in a post grant proceedings the amendment may in fact be a simple restatement of previously agreed upon claim scope, which should not give rise to intervening rights.

Flexibility would appear to be a crucial component of an intervening rights analysis, taking into account the realities of post grant practice. For more discussion on the Marine Polymer case, as well as recent amicus filings, see today’s Patently-O discussion.