אסטרטגיות תביעת בקשת פטנט חיוניות לפטנטים חזקים

Strategic claim drafting and prosecution in the USPTO continues to be of paramount importance. This is especially true in view of the recent U.S. Court of Appeals for the Federal Circuit (CAFC) opinion Colibri Heart Valve LLC v. Medtronic CoreValve, LLC, No. 2023-2153 (Fed. Cir. July 18, 2025)

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The Court held that prosecution history estoppel extends to cancelled claims. As a result, a cancelled claim may serve as a narrowing amendment for another patented claim, provided there is similarity between the claims. This holds true even if the cancelled claim was originally presented and never amended. Specifically, the Court found that a patented claim, which was asserted in litigation, and found to be similar and thus related, to a canceled claim, based on their common language and a shared argument during the infringement trial, which emphasized the centrality of the relevant subject matter in both claims, did not include certain limitations, which were read out of the patented claim upon the cancellation of the similar and related claim.
Once the Court found the patented claim and the cancelled claim to be related, certain limitations from the cancelled claim were removed from the Court’s construction (interpretation) of the patented claim. The cancellation was viewed as a narrowing amendment, and prosecution history estoppel applied. Applying the doctrine of prosecution history estoppel, the patented claim was now interpreted without the cancelled limitation, and was no longer infringed under the longstanding judicially created Doctrine of Equivalents (DOE)—which applies when the infringing article performs substantially the same function, in the same way, to achieve the same result, as the asserted patented claim, with insubtantal differences between the claims.
Although the opinion addressed a unique fact set, the Court’s reasoning suggests a broad application of prosecution history estoppel, now extending to cancelled claims. Further CAFC opinions are needed to determine the application and the breadth of this holding.

Implications for Patent Prosecution

As a result of this decision, claims—particularly independent claims—must be strategically planned, precisely drafted, and cautiously cancelled. Claim drafting now requires heightened attention to precise language to ensure that claims are distinct from each other. Moreover, applicants should be judicious when cancelling claims, as cancelled limitations may be imputed to pending and/or patented claims.

While this has always been a consideration in U.S. patent prosecution, it is an open question whether the decision applies to Patent Cooperation Treaty (PCT) applications, where claims are routinely cancelled, typically prior to national/regional phase filings, to meet national/regional limits (e.g., 15 claims for the EPO and 20 claims for the USPTO).Patent applicants should now prosecute U.S. patent applications with careful consideration of prosecution history estoppel, including the effect on pending or patented claims that which may arise from cancelled claims. The ramifications of decisions made during prosecution require expert strategic support.