United States: Rule Review - Only A True Divisional Can Enter The Safe Harbor Of 35 U.S.C. § 121

Last Updated: October 12 2015
Article by Eric Raciti

For centuries, alchemists attempted to transform base metals such as lead into gold.  Their success against the laws of nature laid out of their reach, but one has to admire the creativity and determination of their efforts.  After all, the potential rewards for success would have been enormous.

The same is true for the U.S. divisional application, which carries a unique and potent protection known as the "safe harbor" provision under 35 U.S.C. § 121:

If two or more independent and distinct inventions are claimed in one application, the Director may require the application to be restricted to one of the inventions.  If the other invention is made the subject of a divisional application which complies with the requirements of section 120 [claiming benefit of priority] it shall be entitled to the benefit of the filing date of the original application.  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.  The validity of a patent shall not be questioned for failure of the Director to require the application to be restricted to one invention. (Emphasis added.)

The true divisional application is therefore noble, like gold, in that it has special and valuable properties.  The true divisional is immune from having its parent used as a reference against it, which notably could occur in an obviousness-type double-patenting (OTDP) rejection. 

As is well known, the judicially made OTDP doctrine seeks to prevent the unfair extension of patent exclusivity beyond the term of a single patent owned by a single patentee.  The public policy behind this doctrine was originally concerned with the unfair extension of patent term when a U.S. patent had a term of seventeen years from its issue date.  Today, with a twenty-year term from the date of filing, this concern is less pressing.1  A terminal disclaimer, nevertheless, requires that a later patent containing claims subject to an OTDP rejection be commonly assigned throughout its life with the parent in order to be enforceable.  This aspect of the OTDP doctrine protects the public from having to defend against charges of infringement from two patentees for practicing an obvious variant of a single invention.  See In re Zickendraht, 319 F.2d 225, 232, 138 U.S.P.Q. 22, 27 (C.C.P.A .1963) (Rich, J., concurring); In re Van Ornum, 686 F.2d 937, 214 U.S.P.Q. 761 (C.C.P.A. 1982).

In G.D. Searle LLC v. Lupin Pharmaceuticals, Inc., No. 2014-1476 (Fed. Cir. June 23, 2015) (Bryson, J.), the U.S. Court of Appeals for the Federal Circuit upheld a district court ruling finding that OTDP rendered a reissue patent invalid.  This case illustrates that an application cannot be styled as a divisional after the fact in order to benefit from the safe harbor of § 121.

Coplaintiffs G.D. Searle and Pfizer sued five generic drug companies for infringement of reissued U.S. Patent No. RE44,048 ("the RE '048 patent").  The RE '048 patent's lineage began with a parent application filed in 1993, which was subject to a three-way restriction requirement identifying two composition groups and one method of use.  Patentee Pfizer elected to prosecute one group of compound claims, which issued as a patent in 1995.  Pfizer filed a divisional application to claim the other composition group, which later issued as U.S. Patent No. 5,563,165 ("the '165 patent") but never filed a divisional to claim the method of use.  Instead, a continuation-in-part application was filed containing new subject matter.

Pfizer also filed a PCT application, which was also designated a continuation-in-part of the parent application.  The PCT application entered the United States in the national stage.  During examination, the national stage application was also subject to a three-way restriction.  Pfizer elected to prosecute a method-of-use group of claims, which was ultimately allowed as U.S. Patent No. 5,760,068 ("the '068 patent").

In Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc., 518 F.3d 1353 (Fed. Cir. 2008), the court addressed a patent infringement action brought by Pfizer on the '068 patent.  The court held that the '068 patent was invalid for OTDP.  In particular, the court found that although the '068 patent shared the same lineage back to the parent application, it was itself a continuation-in-part and not a true divisional, and, therefore, the § 121 safe harbor provision did not apply to the '068 patent.

Pfizer then filed a reissue application, U.S. Patent Application No. 12/205,319 ("the '319 application"), under 35 U.S.C. § 251, stating that it had erred in prosecuting the application as a continuation-in-part rather than as a divisional application.  The reissue application included amendments that removed any subject matter not present in the original parent application, including amending the claims to only recite subject matter appearing in the original parent application.  The reissue examiner, however, rejected the reissue application on the ground that it did not cite an error correctable under the reissue statute.2  In other words, the examiner could not identify where the patent was defective "by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than he had a right to claim in the patent."

Pfizer filed a request for continued examination (RCE) of the '319 application and provided a second reissue declaration, this time specifying various "technical errors" that allegedly rendered the '068 patent indefinite.  The examiner found this declaration to state grounds that were correctable by reissue, and eventually the RE '048 patent issued.

At the district court in G.D. Searle LLC v. Lupin Pharmaceuticals, Inc.,3 the defendants argued that the Pfizer reissue patent was invalid for OTDP because Pfizer was not entitled to invoke the safe harbor in § 121.  The district court agreed, finding that the RE '048 patent was not a true "divisional" and was therefore invalid. Pfizer appealed.

The Federal Circuit first explained that the § 121 safe harbor did not apply to the RE '048 patent because the reissue patent was not a true "divisional" of the parent patent.  According to the court, "[T]he [child] application cannot be a divisional of the [parent] application, despite being designated as such in the reissue patent, because it contains new matter that was not present in the [parent] application."  See G.D. Searle, No. 14-1476, slip op. at 9.  So, even though Pfizer attempted to synthesize a divisional by deleting the new matter filed in the continuation-in-part via reissue proceedings, the Federal Circuit found this to be insufficient, opining that "[s]imply deleting that new matter from the reissue patent does not retroactively alter the nature of the [child] application."  Id.

As an additional reason for denying the safe harbor of § 121 to the RE '048 patent, the court noted that the patent used as a reference for OTDP purposes, the '165 patent, did not derive from the same restriction requirement as the RE '048 patent.  Even though they shared common lineage to the same parent application, the USPTO imposed a separate restriction requirement on the national stage application that matured into the '068 patent.  The Federal Circuit found no evidence that the USPTO intended the earlier restriction requirement in the parent application to carry forward.  Absent this direct relationship, the § 121 safe harbor was found not to apply.

The moral to the story is a simple one.  Applicants in the USPTO wanting to benefit from the § 121 safe harbor should file divisional applications directly from the application where the restriction requirement arises in order to remove any doubt that the divisional application is noble by birth and entitled to the safe harbor by birthright.


1. The question of patent term adjustment (PTA) and patent term extension (PTE) granted by the USPTO as equitable compensation to applicants for administrative delays is a question that intersects with terminal disclaimer practice. Readers with questions related to these complex issues are welcome to contact the author.

2. The applicable section of the (pre-AIA) statute reads: (a) IN GENERAL.--Whenever any patent is, through error without any deceptive intention, deemed wholly or partly inoperative or invalid, by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than he had a right to claim in the patent, the Director shall, on the surrender of such patent and the payment of the fee required by law, reissue the patent for the invention disclosed in the original patent, and in accordance with a new and amended application, for the unexpired part of the term of the original patent.  No new matter shall be introduced into the application for reissue.

3. No. 2:13-cv-00121-AWA-LRL (E.D. Va)

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