The safe-harbor of § 121 applies to all subsequent divisionals so long as consonance with the examiner’s restriction requirement remains.

Boehringer Ingelheim International GMBH v. Barr Laboratories, Inc., No. 2009-1032 (Fed. Cir. Jan. 25, 2010)

In a patent infringement suit involving claims directed to the treatment of Parkinson’s disease, the patent at issue was the third in a chain of related divisional patents. The patent derived from a divisional application of a parent patent, which in turn derived from a divisional application of a grandparent patent. During prosecution of the grandparent application, the examiner issued a restriction requirement listing ten groups of overlapping claims to what the examiner considered to be independent and distinct inventions. The district court rejected the patentee’s argument that the safe-harbor provision of 35 U.S.C. § 121 precluded the use of the parent patent as an invalidating reference to the child patent. Accordingly, the district court found the patent at issue invalid for obviousness-type double patenting. The Federal Circuit reversed and remanded, concluding that the safe-harbor provision of § 121 applied to preclude invalidity.

The safe harbor of § 121 is provided to shield a patent from invalidity on the basis of double patenting when an application is divided “as a result” of a restriction requirement assessed by an examiner. The “as a result of” provision in § 121 must be satisfied by both the reference patent and the challenged patent (in this case the parent and child patents). “[S]o long as consonance is met, it makes no difference in terms of compliance with the ‘as a result of’ requirement whether the applicant responds to the examiner’s restriction by filing one or more divisional applications from the original application, or instead files a single divisional application followed by successive additional divisionals.” The statute “refers broadly to ‘a divisional application,’ and does not state that the divisional must be a direct divisional of the original application.” “Consonance” is defined as the situation where “the line of demarcation between the ‘independent and distinct inventions’ that prompted the restriction requirement be maintained.”

The patentee’s divisional applications encompassed different combinations of the inventions set forth as being distinct in the restriction requirement. The applications also included an overlap of claims to the various distinct inventions. Such “overlap of claims to independent and distinct inventions within a given divisional application is neither contrary to the restriction requirement nor relevant to the requirements of . . . § 121.” Because none of the inventions of the three divisional applications crossed the examiner’s lines of demarcation, consonance was met and the parent patent could not be used as a reference against the child patent at issue.

A dissenting opinion by Judge Dyk followed a more narrow interpretation of the scope of § 121’s safe-harbor provision, defining “consonance” as requiring complete and strict adherence to the contours of the restriction requirement, which would not allow for applicants to combine in a single application claims that the examiner determined were drawn to separate inventions.

A copy of the opinion can be found here.