  United States Court of Appeals
      for the Federal Circuit
                ______________________

  G.D. SEARLE LLC, PFIZER ASIA PACIFIC PTE.
                       LTD.,
               Plaintiffs-Appellants

                          v.

        LUPIN PHARMACEUTICALS, INC.,
               Defendant-Appellee

      TEVA PHARMACEUTICALS USA, INC.,
              Defendant-Appellee

        MYLAN PHARMACEUTICALS INC.,
               Defendant-Appellee

         WATSON LABORATORIES, INC.,
                  Defendant

          APOTEX INC., APOTEX CORP.,
               Defendants-Appellee
             ______________________

                      2014-1476
                ______________________

   Appeal from the United States District Court for the
Eastern District of Virginia in No. 2:13-cv-00121-AWA-
LRL, Judge Arenda L. Wright Allen.
                ______________________

                Decided: June 23, 2015
                ______________________
2            G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



    KANNON K. SHANMUGAM, Williams & Connolly LLP,
Washington, DC, argued for plaintiffs-appellants. Also
represented by ALLISON B. JONES, DAVID M. KRINSKY,
CHRISTOPHER ALAN SUAREZ; AARON STIEFEL, SOUMITRA
DEKA, DANIEL REISNER, JEFFREY T. MARTIN, DANIEL
DINAPOLI, Kaye Scholer LLP, New York, NY.

    BETH D. JACOB, Kelley Drye & Warren, LLP, New
York, NY, argued for defendant-appellee Lupin Pharma-
ceuticals, Inc. Also represented by CLIFFORD KATZ;
DOUGLASS C. HOCHSTETLER, Chicago, IL.

    HENRY C. DINGER, Goodwin Procter LLP, Boston, MA,
argued for defendant-appellee Teva Pharmaceuticals
USA, Inc. Also represented by KEITH A. ZULLOW, DAVID
M. HASHMALL, New York, NY; WILLIAM M. JAY, Washing-
ton, DC.

   DOUGLAS H. CARSTEN, Wilson, Sonsini, Goodrich &
Rosati, PC, San Diego, CA, argued for defendant-appellee
Mylan Pharmaceuticals Inc. Also represented by PETER
SOO KANG; NANCY L. ZHANG, Palo Alto, CA.

   STEPHEN AUTEN, Taft, Stettinius & Hollister, LLP,
Chicago, IL, argued for defendants-appellees Apotex Inc.,
Apotex Corp. Also represented by IAN SCOTT, RICHARD T.
RUZICH; RICHARD HOOPER OTTINGER, Vandeventer Black
LLP, Norfolk, VA.
                 ______________________

      Before PROST, Chief Judge, BRYSON and HUGHES,
                    Circuit Judges.
BRYSON, Circuit Judge.
     G.D. Searle LLC and Pfizer Asia Pacific Pte. Ltd. (col-
lectively, “Pfizer”) appeal from a final judgment entered
by the United States District Court for the Eastern Dis-
trict of Virginia. The court invalidated the relevant
claims of Pfizer’s reissued U.S. Patent No. RE44,048 (“the
G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.          3



RE ’048 patent”) for obviousness-type double patenting.
We affirm.
                               I
    The doctrine of obviousness-type double patenting is
intended to prevent the extension of the term of a patent
by prohibiting the issuance of the claims of a second
patent that are not patentably distinct from the claims of
the first patent. Eli Lilly & Co. v. Teva Parenteral Meds.,
Inc., 689 F.3d 1368, 1376 (Fed. Cir. 2012). The double-
patenting issue in this case turns on whether Pfizer is
entitled to invoke section 121 of the Patent Act, 35 U.S.C.
§ 121, as a defense against a claim of double patenting.
That issue in turn depends on an interpretation of the
prosecution history of the RE ’048 patent and U.S. Patent
No. 5,760,068 (“the ’068 patent”), which is the original of
the RE ’048 patent.
     The ’068 patent can be traced back to an application
filed with the Patent and Trademark Office (“PTO”) in
1993. That application, Serial No. 08/160,594 (“the ’594
application”), disclosed and claimed compounds, composi-
tions, and methods of use regarding the treatment of pain
and inflammation without the harmful side effects associ-
ated with certain traditional anti-inflammatory drugs.
     In an office action dated July 12, 1994, the patent ex-
aminer imposed a three-way restriction requirement on
the ’594 application. The restriction requirement identi-
fied the compound, composition, and method-of-use claims
as each directed to patentably distinct subject matter, and
it required Pfizer to elect only one of the three classes of
claims. Pfizer elected to prosecute the compound claims
in the ’594 application, which issued in November 1995 as
U.S. Patent No. 5,466,823.
    Pfizer prosecuted the composition claims that had
been restricted out of the ’594 application in a divisional
application filed in June 1995, Serial No. 08/457,059 (“the
’059 application”). The ’059 application matured into U.S.
Patent No. 5,563,165 (“the ’165 patent”) in October 1996.
4            G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



    Pfizer did not file a divisional application to prosecute
the restricted-out method-of-use claims of the ’594 appli-
cation. Instead, prior to receiving the restriction re-
quirement, it filed a continuation-in-part of the ’594
application in April 1994, Serial No. 08/223,629 (“the ’629
application”) that included new matter. The ’629 applica-
tion contained all three classes of claims, i.e., compounds,
compositions, and methods of use, including claims cover-
ing the new matter, and it issued as U.S. Patent No.
5,521,207 in May 1996.
    In November 1994, Pfizer filed International Patent
Application No. PCT/US94/12720 (“the PCT ’720 applica-
tion”), which was designated as a continuation-in-part of
the ’629 application and as a continuation-in-part of the
original ’594 application. The PCT ’720 application con-
tained all three classes of claims, and it encompassed
much of the subject matter in the method-of-use claims
that had been restricted out of the ’594 application.
    The PCT ’720 application became a national stage ap-
plication in the United States as U.S. Patent Application
No. 08/648,113 (“the ’113 application”) in September 1996.
During the prosecution of the ’113 application, the exam-
iner issued a lack of unity rejection/restriction require-
ment in a telephone conference with the patentee. That
restriction requirement again limited Pfizer to prosecut-
ing only one of the three classes of claims—compounds,
compositions, or methods of use. Pfizer elected to prose-
cute only method-of-use claims in the ’113 application,
which matured into the ’068 patent in June 1998. The
’068 patent describes itself as issuing from a continuation-
in-part of the ’629 application, which was a continuation-
in-part of the original ’594 application.
    In Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc., 518
F.3d 1353 (Fed. Cir. 2008), which addressed a patent
infringement action filed by Pfizer on the ’068 patent, we
held the relevant claims of the ’068 patent invalid for
obviousness-type double patenting in light of the earlier
issued ’165 patent. In that case, Pfizer invoked the so-
G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.            5



called “safe harbor” provision of section 121, which in
certain circumstances protects a patent that issues on a
divisional application from invalidation based on a related
patent that issued on an application as to which a re-
striction requirement was made, or on an application filed
as a result of such a requirement. We held that even
though both the ’165 patent and the ’068 patent traced
their lineage back to the original ’594 application, the
statutory safe harbor provision did not shield the ’068
patent from the invalidating effect of the ’165 patent.
That was because “the protection afforded by section 121
to applications (or patents issued therefrom) filed as a
result of a restriction requirement is limited to divisional
applications,” id. at 1362, and the ’068 patent issued from
a continuation-in-part, not a divisional application.
    Pfizer subsequently filed U.S. Patent Application No.
12/205,319 (“the ’319 application”), seeking reissue of the
’068 patent under 35 U.S.C. § 251. 1 In the reissue decla-



   1   At the relevant time, section 251 read as follows:
   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 pa-
   tentee 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 in-
   vention disclosed in the original patent, and in ac-
   cordance with a new and amended application, for
   the unexpired part of the term of the original pa-
   tent. 35 U.S.C. § 251(a).
    The America Invents Act amended the statute by
striking the words “without any deceptive intention.”
Pub. L. No. 112-29, § 20, 125 Stat. 284, 333-34 (2011). The
amendment took effect on September 16, 2012, after
6            G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



ration, Pfizer asserted that it had erred in prosecuting the
application leading up to the ’068 patent as a continua-
tion-in-part, rather than as a divisional application, and
that the error had resulted in invalidating the relevant
claims of the ’068 patent for obviousness-type double
patenting.
    Pfizer sought to correct that alleged error by reissue.
The preliminary amendment that accompanied the initial
reissue declaration made the following changes to the ’068
patent: (1) it deleted portions of the ’068 patent specifica-
tion that were not present in the ’594 application; (2) it
designated the ’113 application as a divisional of the ’594
application and removed the priority claim to the ’629
application; (3) it amended claim 1 to be a method claim
using only the compounds originally disclosed in the ’594
application; (4) it canceled claims 2-12, which were meth-
od claims using compounds that were not present in the
’594 application; (5) it canceled claim 18 (reciting a meth-
od of preventing colorectal cancer), which was not found
in the ’594 application; and (6) it added new method
claims 19-23, which recited the use of the method dis-
closed in claim 1 to treat five specific types of inflamma-
tion-associated disorders. The preliminary amendment
stated that those actions were taken to conform the ’068
patent to a divisional of the ’594 application.
    The examiner rejected the preliminary amendment,
finding that the “error” identified in Pfizer’s reissue
declaration was not correctable under section 251. Pfizer
then filed a request for continuing examination and
submitted an additional reissue declaration, in which it
cited various technical errors relating to the claimed
chemical structures that it wished to correct through the
reissue. Those technical errors, according to Pfizer,
rendered the claims of the ’068 patent indefinite and were



Pfizer had filed its reissue application on September 5,
2008. “Deceptive intention” is not at issue in this case.
G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.         7



therefore eligible for correction by reissue under section
251.
    The examiner found that the later-identified technical
errors provided a proper basis for reissue under section
251. Pfizer was allowed to correct those technical errors;
it was also allowed to make additional changes, including
designating the ’113 application from which the ’068
patent issued as a divisional of the ’594 application and
removing subject matter not present in the ’594 applica-
tion. The PTO eventually allowed the claims of the ’319
application, which issued as the RE ’048 patent on March
5, 2013.
    On the day the RE ’048 patent issued, Pfizer filed the
instant case against five generic drug manufacturers,
alleging infringement of the RE ’048 patent. The generic
manufacturers moved for summary judgment, and the
district court granted the motion in part. The court found
that the RE ’048 patent was not a valid reissue patent,
because Pfizer’s asserted error of prosecuting a prior
patent application as a continuation-in-part, rather than
as a divisional, was not correctable by reissue under
section 251. The court further found that the safe harbor
provision of 35 U.S.C. § 121 did not apply to the RE ’048
patent, and that the relevant claims of the RE ’048 patent
were invalid for obviousness-type double patenting in
light of the ’165 patent. A final judgment of invalidity
was entered against Pfizer. This appeal followed.
                               II
    The parties present two principal issues on appeal: (1)
whether 35 U.S.C. § 251 authorized the PTO to reissue
the ’068 patent under the circumstances; and (2) assum-
ing reissue was authorized, whether the safe harbor
provision of 35 U.S.C. § 121 applies to the RE ’048 patent
and protects it from invalidation based on the ’165 patent.
Because we find that the safe harbor provision of section
121 does not apply to the RE ’048 patent, even assuming
8            G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



it was proper to grant the reissue patent under section
251, we affirm the district court’s judgment.
     The safe harbor provision of section 121 provides as
follows:
    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 divi-
    sional application or against the original applica-
    tion or any patent issued on either of them, if the
    divisional application is filed before the issuance
    of the patent on the other application.
We apply “a strict test” for application of section 121,
“[g]iven the potential windfall [a] patent term extension
could provide to a patentee.” Geneva Pharm., Inc. v.
GlaxoSmithKline PLC, 349 F.3d 1373, 1382 (Fed. Cir.
2003); see also Amgen Inc. v. F. Hoffman-La Roche Ltd.,
580 F.3d 1340, 1353 (Fed. Cir. 2009) (requiring “a strict
application of the plain language of § 121”).
   Pfizer contends that the RE ’048 patent is entitled to
the protection of the safe harbor provision against invali-
dation by the ’165 patent. We disagree.
                               A
    The safe harbor provision of section 121 protects a pa-
tent issuing on an application with respect to which a
restriction requirement has been made, or on an applica-
tion filed as a result of such a restriction requirement. 35
U.S.C. § 121; Pfizer, 518 F.3d at 1360. It is undisputed
that the reference ’165 patent issued on a divisional of the
original ’594 application, which was filed as a result of the
July 1994 restriction requirement. The challenged RE
’048 patent, however, is not entitled to safe harbor protec-
tion, because it did not issue on either the ’594 application
or a divisional of the ’594 application.
G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.           9



    The RE ’048 patent issued from the ’319 application, a
reissue of the ’068 patent, which in turn issued from the
’113 application. The ’113 application cannot be a divi-
sional of the ’594 application, despite being designated as
such in the reissue patent, because it contains new matter
that was not present in the ’594 application. See PTO,
Manual of Patent Examining Procedure § 201.06 (9th ed.
2014) (“A later application for an independent or distinct
invention, carved out of a pending application and disclos-
ing and claiming only subject matter disclosed in the
earlier or parent application, is known as a divisional
application or ‘division.’”). Simply deleting that new
matter from the reissue patent does not retroactively alter
the nature of the ’113 application.
    Moreover, when the ’113 application issued as the
’068 patent in June 1998, Pfizer obtained patent protec-
tion for the new matter that was not present in the ’594
application. For years thereafter, the public was not free
to practice that new matter (e.g., the now cancelled claims
2-12 and 18 of the ’068 patent) because of that patent
protection. Pfizer cannot now identify the ’113 applica-
tion as a divisional of the ’594 application (for purposes of
section 121) and retroactively relinquish the new matter
in the ’113 application, after having enjoyed years of
patent protection for it. See In re Harita, 847 F.2d 801,
809 (Fed. Cir. 1988) (“In any given case, the [reissue]
statute should be so applied to the facts that justice will
be done both to the patentee and the public.”); see also In
re Serenkin, 479 F.3d 1359, 1362 (Fed. Cir. 2007) (“[Sec-
tion] 251 is based on fundamental principles of equity and
fairness[.]”). Fairness to the public does not permit Pfizer
to convert the ’113 application into a division of the origi-
nal ’594 application, and thereby take advantage of the
safe harbor provision, simply by designating it as a divi-
sional application years after the fact.
    The ’113 application is a national stage application of
the PCT ’720 application. The PCT ’720 application, like
the ’113 application, is not a division of the ’594 applica-
10           G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



tion. PCT ’720 identified itself as a continuation-in-part
of the ’594 application and as a continuation-in-part of the
’629 application; it added compound, composition, and
method-of-use claims that were not contained in those
applications.
     Pfizer does not assert that the PCT ’720 application
can become a divisional application of the ’594 application
for section 121 purposes simply by disregarding all matter
not present in the original ’594 application, and for good
reason. Pfizer obtained foreign patent protection based
on the PCT ’720 application. Altering the scope of the
PCT ’720 application could call into question the proper
scope of those foreign patents. Thus, because the PCT
’720 application contains matter not present in the origi-
nal ’594 application, it cannot be a division of the ’594
application.
    Because the RE ’048 patent identifies itself as de-
scended from the ’113 application and the PCT ’720
application, and because neither of those applications is a
division of the original ’594 application, the section 121
safe harbor does not apply to the RE ’048 patent. See
Pfizer, 518 F.3d at 1362 (“We conclude that the protection
afforded by section 121 to applications (or patents issued
therefrom) filed as a result of a restriction requirement is
limited to divisional applications.”); Amgen Inc. v. F.
Hoffman-La Roche Ltd., 580 F.3d 1340, 1352-53 (Fed. Cir.
2009) (same). 2



     2   Pfizer suggests that the reissue application itself
(i.e., the ’319 application) may also be deemed a division
of the ’594 application for purposes of section 121. See,
e.g., Applicants’ Reply Br. 23-25. That position, however,
is inconsistent with the record. The RE ’048 patent states
that it is a reissue of the ’068 patent, which issued from
the ’113 application, which in turn is designated as a
divisional of the ’594 application. That characterization
accords with Pfizer’s stated purpose for seeking reissue,
G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.         11



                               B
    Section 121 is inapplicable to the RE ’048 patent for a
second reason as well: The RE ’048 patent (the challenged
patent) and the ’165 patent (the reference patent) are not
“derived from the same restriction requirement.” Pfizer,
518 F.3d at 1360; see also Boehringer Ingelheim Int’l
GmbH v. Barr Labs., Inc., 592 F.3d 1340, 1354 (Fed. Cir.
2010) (section 121 protects “claims prosecuted in two or
more applications having common lineage in a divisional
chain”).
     When separate restriction requirements are imposed
on separate applications and the record does not show
that any of the various restriction requirements carried
forward from one application to the next, the earlier
restriction requirement cannot be viewed as having
continued in effect with respect to the later-filed applica-
tion. See Bristol-Myers Squibb Co. v. Pharmachemie B.V.,
361 F.3d 1343, 1349-50 (Fed. Cir. 2004).
    In 1994, the examiner imposed a three-way restriction
requirement on the original ’594 application (the “1994
restriction requirement”), prohibiting Pfizer from prose-
cuting all three classes of claims—compounds, composi-
tions, and methods of use—in the same application.
Pfizer elected to prosecute the compound claims in the
’594 application and separately prosecuted the composi-
tion claims in the ’059 application, a division of the ’594
application.




i.e., “so that the ’113 Application from which the ’068
Patent issued qualifies as a divisional application in
compliance with the recent Federal Circuit opinion.” The
evidence thus shows that the reissue patent relies on its
lineage from the ’113 application, and not from the ’319
application, to satisfy the “divisional application” re-
quirement of section 121.
12           G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



    The ’059 application matured into the ’165 patent. It
is undisputed that the ’165 patent is derived from the
1994 restriction requirement. The RE ’048 patent, on the
other hand, identifies itself as being descended from the
’113 application and the PCT ’720 application. Both of
those applications, as filed, contained three classes of
claims: compounds, compositions, and methods of use.
During the national stage prosecution of the ’113 applica-
tion, and in an April 8, 1997, supplemental amendment,
Pfizer noted that the examiner had issued “[a] lack of
unity rejection/restriction requirement” during a tele-
phone conference (the “1997 restriction requirement”).
The 1997 restriction requirement again limited Pfizer to
an election among the claimed compounds, compositions,
and methods of use. Pfizer elected to prosecute only
method-of-use claims in the ’113 application, which ma-
tured into the ’068 patent. Appellants’ Br. 5 (“After the
examiner issued a restriction requirement, Pfizer amend-
ed the ’113 application to elect, with traverse, only the
method-of-treatment claims.”).
    The record thus shows that two separate restriction
requirements affected the chain of applications involved
in this case. The 1994 requirement, which was imposed
on the original ’594 application, led to the ’165 patent.
The 1997 requirement, which was imposed on the ’113
application, led to the ’068 patent and ultimately to the
RE ’048 patent. In order for section 121 to protect the RE
’048 patent against the invalidating effect of the ’165
patent, the 1994 restriction requirement must have
“carried forward” from the ’594 application to the ’113
application. Bristol-Myers, 361 F.3d at 1349. No such
showing has been made, however.
      Pfizer admits that the ’113 application contains
claims directed at “subject matter that was newly added
. . . and had not been disclosed in the . . . ’549 applica-
tion[].” Appellants’ Br. 22. Thus, while the 1994 re-
striction requirement and the 1997 restriction
requirement both limited Pfizer to an election among
G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.         13



compounds, compositions, and methods of use, they did
not apply to the same compounds, compositions, and
methods of use. They are therefore not the same re-
striction requirement.
    Furthermore, the record is devoid of any evidence
showing that the examiner “reinstate[d] or even ad-
vert[ed] to” the 1994 restriction requirement when issuing
the 1997 restriction requirement. Bristol-Myers, 361 F.3d
at 1348-49. There is no evidence that the examiner made
any reference to the 1994 restriction requirement at all
during prosecution of the ’113 application. Without such
evidence, the 1994 and the 1997 restriction requirements,
although appearing similar, must be deemed to have been
“separately imposed with respect to” the ’594 and the ’113
applications. Id. at 1349. Because the ’165 patent and
the RE ’048 patent are derived from two separately im-
posed restriction requirements, section 121 does not apply
as between those two patents.
    Pfizer contends that the 1994 restriction requirement
nonetheless should be deemed to have carried forward to
the ’113 application because, “but for the [1994] re-
striction requirement” Pfizer could have pursued the
claims contained in the RE ’048 patent in the original ’594
application. Pfizer relies on the Boehringer case for the
proposition that if the claims at issue would have been
prosecuted in the original application but for the re-
striction requirement, they must be deemed to have been
derived from that restriction requirement. Appellants’
Reply Br. 24. Boehringer, however, does not go that far.
    The issue in Boehringer was whether section 121 ap-
plies to a patent that issues from an application that is a
divisional of a divisional of the application upon which a
restriction requirement was imposed. See Boehringer, 592
F.3d at 1352. In Boehringer, a single restriction require-
ment was entered in the grandparent application. The
patentee then filed two successive divisionals to different
combinations of the inventions identified in the restriction
requirement. We held that section 121 applies to a divi-
14           G.D. SEARLE LLC   v. LUPIN PHARMACEUTICALS, INC.



sional of a divisional of the grandparent application, so
long as (1) the claims prosecuted in two or more applica-
tions share common lineage in the divisional chain; and
(2) the lines of demarcation drawn by the examiner are
preserved as between applications. Id. at 1354.
    In Boehringer, common lineage was not at issue, be-
cause that case involved a single restriction requirement
imposed only on the grandparent application. Here, by
contrast, the record shows two separate restriction re-
quirements, one of which led to the reference ’165 patent
and the other of which led to the challenged RE ’048
patent. This case requires us to answer the question
whether the applications from which the two patents
issued share “common lineage in the divisional chain”; in
other words, we must determine whether the two patents
are derived from the same restriction requirement.
Boehringer, 592 F.3d at 1354; Pfizer, 518 F.3d at 1360.
    As noted above, the 1994 and 1997 restriction re-
quirements were not imposed on the same compound,
composition, and method-of-use claims. No evidence
shows that the PTO intended the 1994 restriction re-
quirement to carry forward to the ’113 application. Thus,
the record does not show that the 1994 and 1997 re-
striction requirements are one and the same, and the
“common lineage” requirement of Boehringer is not satis-
fied. For that reason as well, we hold that the safe harbor
provision of section 121 does not apply to protect the RE
’048 patent from the use of the ’165 patent in the obvious-
ness-type double patenting analysis. 3
                      AFFIRMED




     3 Because we conclude that the section 121 safe
harbor provision does not apply to the RE ’048 patent, we
need not address the question whether the RE ’048 patent
was validly reissued under 35 U.S.C. § 251.
