United States: The Danger Of Double Patenting

In St. Jude Medical, Inc. v. Access Closure, Inc., the Federal Circuit found that one of St. Jude's patents was invalid under the doctrine of obviousness-type double patenting. This case highlights the potential difficulty of maintaining consonance with an original restriction requirement in a multi-generational patent family.

The Patent At Issue

Although there were three St. Jude patents at issue in the case before the Federal Circuit, only one was caught up in the double patenting issue, U.S. Patent 7,008,439 (the Janzen patent).

The Janzen patent stems from a grandparent application that was subject to a restriction requirement that restricted the claims along the following lines:

Group I. Claims . . . drawn to a device for use in sealing a puncture in a wall of a blood vessel.

Group II. Claims . . . drawn to a method of sealing a puncture in a wall of a blood vessel.

Species A: Claims relating to the apparatus comprising a solid tissue dilator.

Species B: Claims relating to the apparatus comprising a hollow dilator and guidewire.

Species C: Claims relating to the apparatus comprising a guidewire and no dilator.

Group I, Species B, was elected in the grandparent application, which issued as U.S. Patent 5,391,183.

The parent application was filed as a "divisional" application, and was subject to a similar restriction requirement. The Applicant again elected Group I, Species B. The parent application issued as U.S. Patent 5,830,130.

The Janzen application was filed as a "continuation" application of the parent application. The Applicant canceled the original claims and "copied both device and method claims from a different patent to provoke an interference proceeding." As summarized by the Federal Circuit, "[t]he Janzen application ultimately prevailed in the interference, and issued with both device and method claims."

The Applicant filed another continuation of the parent application, which issued before the Janzen patent as U.S. Patent 5,725,498 with method claims.

The District Court Proceedings

St. Jude asserted its patents against ACI. The district court construed the claims, and issues of validity and infringement were tried to a jury. As summarized by the Federal Circuit,

The jury rendered a verdict that ACI had infringed claims 7 and 8 of the Janzen patent, but that claims 7, 8, and 9 of the Janzen patent were invalid for double patenting in light of the sibling '498 patent. Implicit in the jury's double patenting finding was the jury's conclusion that claims 7, 8, and 9 of the Janzen patent were not patentably distinct from claim 7 of the sibling patent.

However, the district court treated the jury verdict on the double patenting issue as "advisory" because it had not had the jury decide whether 35 USC § 121 prevented the claims from being invalid on that ground. The court thus held a bench trial on that issue, and determined that § 121 did apply, and saved the Janzen patent from double patenting.

The Federal Circuit Decision

The Federal Circuit opinion was authored by Judge Plager, and joined by Judge Wallach. Judge Lourie wrote a concurring opinion.

The Federal Circuit cited the "safe harbor" portion of § 121:

A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application.

ACI's arguments focused on the "consonance" requirement of the safe harbor, which derives from the "as a result of" language of the statute. As explained by the Federal Circuit, in order for the safe harbor to apply, "the 'line of demarcation between the "independent and distinct inventions" that prompted the restriction requirement [must] be maintained.'"

The Federal Circuit cited previous precedent as providing the following guidance on the consonance requirement:

On the one hand:

  • An applicant's pursuit of two or more non-elected inventions in the same subsequent application does not by itself violate the line of demarcation. See Boehringer Ingelheim Int'l GmbH v. Barr Labs, Inc., 592 F.3d 1340, 1350 (Fed. Cir. 2010).
  • "Plain common sense dictates that a divisional application filed as a result of a restriction requirement may not contain claims drawn to the invention set forth in the claims elected and prosecuted to patent in the parent application." Gerber Garment Tech., Inc. v. Lectra Sys., Inc., 916 F.2d 683, 687 (Fed. Cir. 1990).


The requirement for consonance applies to both the patent challenged for double patenting (the challenged patent) and the patent being used as a reference.

Accordingly, the court reasoned:

Consonance in a case like this requires that the challenged patent, the reference patent, and the patent in which the restriction requirement was imposed (the restricted patent) do not claim any of the same inventions identified by the examiner.

With regard to the case at hand, ACI argued that the only relevant "demarcation" was that drawn between the device claims (Group I) and the method claims (Group II), while St. Jude argued that each Group/Species combination constituted its own "demarcation."

On this issue, the majority of the Federal Circuit agreed with St. Jude. The court reviewed the USPTO regulation regarding election of species (37 CFR § 1.146) and noted that an election of species has the same effect as a restriction requirement if no generic claim linking the species is found to be allowable. The court also noted that in the grandparent application, no generic claim was presented or allowed. Thus, the court held that "the restriction resulting from the election of species affected the line of demarcation. In particular, the first restriction separated Group I from Group II, and the second restriction operated on top of the first restriction to separate the Species."

To determine whether the line of demarcation was "honored," the Federal Circuit considered "whether any of the same restricted inventions are claimed in the challenged patent (the Janzen patent), the reference patent (the sibling patent), or the restricted patent (the grandparent patent)," and did so as a question of law, without deference to the district court decision.

The Federal Circuit categorized the claimed subject matter as follows:

Grandparent Patent: Group I, Species B

Janzen Patent: Group I, Species C; Group II, Species C

Sibling Patent: Group II, generic as to species.

The court found the line of demarcation honored as between the grandparent patent and the Janzen patent, it found that it was not honored in the sibling patent:

The sibling patent's independent claim 1 is ... a claim directed to Group II, but not limited to any of Species A, B, or C .... Thus the sibling application was not filed "as a result" of the restriction since it pursued a claim generic to all Species in Group II, and therefore overlapped Group II, Species C found in the Janzen patent.

Having found that the consonance requirement was not met, the Federal Circuit held that the safe harbor of § 121 does not apply. In view of the jury's finding that claims 7, 8, and 9 of the Janzen patent are not patentably distinct from claims of the sibling patent, the court held claims 7, 8, and 9 of the Janzen patent invalid.

Judge Lourie's Concurrence

In his concurring opinion, Judge Lourie parts ways with the majority decision on the effect of the election of species requirement. In particular, Judge Lourie disagrees that the election of species requirement is relevant to the § 121 inquiry.

Such a requirement for election of species is not the same as a restriction requirement. It is tentative and its consequences are avoidable by the applicant obtaining the allowability of a generic claim encompassing the various species or by filing separate applications to pursue the nonelected subject matter. In my view, the district court and the majority err in even considering the effect of the requirement for election of species in this case.

Judge Lourie would have based the finding of lack of consonance on the presence of both device device claims (Group I) and method claims (Group II) in the Janzen patent.

An Expensive Ticket To The Safe Harbor

Although the original restriction requirement in this case contained only two groups of claims, it is not uncommon to receive multi-way restriction requirements that seem to divide each word of a claim into a separate group. Applicants faced with such restriction requirements must weigh the benefits of the safe harbor of § 121 with the costs of prosecuting and maintaining multiple applications directed to the same technology (if not the same invention). Applicants may try to pursue several groups of claims in or more "divisional" applications, hoping that the examiner will not be as zealous with the restriction requirement. Applicants also may purse claims of different scope in one or more "continuation" applications. This case serves as a reminder that these strategies may risk losing the consonance that is required to avoid double patenting issues. Sometimes, however, the price of a ticket to the safe harbor may not be worth its benefits, as long as validity of the patents can be saved with a Terminal Disclaimer.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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