In a recent decision, the Patent Trial and Appeal Board (PTAB) narrowly construed the so-called safe harbor provision of 35 U.S.C. § 121, affirming the examiner’s rejection of a patent application under the doctrine of “obviousness-type double patenting” (OTDP). Ex parte Sauerberg, Appeal 2015-007064 2017 WL 150016 *1 (PTAB Jan. 10, 2017).
The safe harbor protects later-filed divisional applications from rejection or invalidation under the doctrine of obviousness-type double patenting (OTDP). It ensures that
[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.
35 U.S.C. § 121 (emphasis added). A number of decisions have construed this provision in various circumstances relating to the sequential filing of divisional, continuation and continuation-in-part applications off the original parent application.
Most recently, in Ex parte Sauerberg, the PTAB weighed in, advancing perhaps the narrowest construction of the safe harbor to date.
In Sauerberg, the applicant filed an “original application” directed to certain pharmaceutical compositions and their use in treating diabetes and related diseases. The examiner issued a restriction requirement, requiring the applicant to elect between Group I compound claims and Group II method claims. The applicant elected Group I and successfully prosecuted the application, obtaining a first patent in May 2011.
During the pendency of this original application, the applicant filed a first continuation and later a second continuation, each directed to different aspects of the Group I compound claims, and each ultimately resulting in a patent – the second and third patents in the family, issuing in January and October 2013, respectively.
During the pendency of the second continuation, the applicant filed a divisional application directed to the originally unelected method claims, based on the restriction requirement issued in the original application. Importantly, the divisional application was filed after the issuance of the first and second patents. The examiner rejected the divisional application on the grounds of OTDP over all three patents.
The applicant appealed to the PTAB on the theory that the examiner erred in asserting the OTDP rejections because the divisional application was entitled to protection under the § 121 safe harbor. On appeal, the Board construed § 121, finding that it did not shield the applicant’s divisional application from the examiner’s OTDP rejections.
First, the Board determined that the divisional was not filed “as a result of” the original restriction requirement as required by § 121. The safe harbor applies to “[a] patent issuing on an application with respect to which” a restriction requirement was made, or a patent issuing on “an application filed as a result of such a requirement.”
The Board held that the divisional application in this case was not “an application filed as a result of” the restriction requirement in the original application because the Group I subject matter pursued in the first and second continuations was in no way precluded from being incorporated in the original application. Therefore, the Board reasoned, these continuations failed to satisfy the “as a result of” requirement of the safe harbor. Consequently, the divisional filed after the continuations could not have been filed “as a result of” the original restriction requirement. In other words, the Board required the applicant to show that the intervening continuation applications (not the divisional itself) were filed as a result of the restriction requirement. This the applicant failed to do. Thus, the Board held that the examiner did not err in asserting the second and third patents as OTDP references against the divisional application.
Second, the Board determined that the divisional application was not filed before the parent application issued, even though the co-pendency requirement of § 120 was satisfied. According to the Board, the safe harbor applies only to divisional applications “filed before the issuance of the patent on the other application.”
Here again, the Board construed the statutory language narrowly. Rejecting the applicant’s arguments, the Board reasoned that it is the actual filing date, not the effective filing date, that must be considered for purposes of determining applicability of an OTDP reference against a pending application. The Board determined that “the effective filing date of a patent application is largely irrelevant in the context of a double patenting rejection” because such rejections are based on the substance of the claims of the reference and challenged applications, not the filing dates. Id. at *5. Accordingly, because the divisional in this case was filed after the issuance of the first patent, the Board held that the examiner did not err in asserting the first patent as an OTDP reference against the divisional application.
According to this decision, and in conjunction with current Federal Circuit case law, § 121 should be strictly construed. In order to enjoy the protection of the safe harbor against OTDP rejections, an application must:
- Be properly designated a “divisional” application at the time of filing.
- Be filed “as a result of” a restriction requirement, meaning:
a. Filed as a divisional of the application in which the restriction requirement was issued.
b. Directed to the subject matter restricted in the requirement and not elected in the prior application.
- Be filed before the issuance of the reference patent (or the patent in which the restriction requirement was issued).
In light of this decision, patent practitioners should strongly counsel applicants to file divisional applications before the issuance of a patent in a case in which the examiner issued a restriction requirement, even if the applicant wishes to first pursue claims directed to the elected subject matter in further continuations.
 See, e.g., G.D. Searle LLC v. Lupin Pharm., Inc., 790 F.3d 1349, 1355 (Fed. Cir. 2015) (holding the safe harbor did not shield a continuation-in-part of a prior continuation-in-part filed off the original reference application, even where the designation of the patent subject to OTDP was changed by reissue to a divisional); Boehringer Ingelheim Int’l GmbH v. Barr Labs., Inc., 592 F.3d 1340, 1351 (Fed. Cir. 2010) (holding that the safe harbor did protect a divisional of a divisional application filed off of the reference application); Amgen Inc. v. F. Hoffman-La Roche Ltd, 580 F.3d 1340, 1354 (Fed. Cir. 2009) (holding the safe harbor did not protect continuation applications of continuations filed off the reference application); and Symbol Techs., Inc. v. Opticon, Inc., 935 F.2d 1569 (Fed. Cir. 1991) (holding the safe harbor shielded a continuation of a divisional application filed off the reference application).
 35 U.S.C. § 120, incorporated by reference into § 121, provides that an application, e.g., a continuation or a divisional application, can obtain the benefit of an earlier filing date of a prior filed related application under certain circumstances.
 The applicant filed terminal disclaimers following this decision, and the application was allowed. Thus, no appeal was taken to the Federal Circuit in this case.
 See G.D. Searle LLC, 790 F.3d at 1354–55 (holding that re-designating a patent as a divisional by reissue does not does not qualify it for the protection under the safe harbor).