Court Opinion

ID: 4545511
Source: CourtListenerOpinion
Date Created: 2020-07-01 16:00:36.593574+00
Date Added: 2024-06-11T12:52:11.394376
License: Public Domain

Case: 20-1037    Document: 97     Page: 1   Filed: 07/01/2020

   United States Court of Appeals
       for the Federal Circuit
                  ______________________

         IMMUNEX CORPORATION, AMGEN
           MANUFACTURING, LIMITED,
               Plaintiffs-Appellees

             HOFFMANN-LA ROCHE INC.,
                    Plaintiff

                             v.

  SANDOZ INC., SANDOZ INTERNATIONAL GMBH,
                SANDOZ GMBH,
               Defendants-Appellants
              ______________________

                        2020-1037
                  ______________________

     Appeal from the United States District Court for the
 District of New Jersey in No. 2:16-cv-01118-CCC-MF,
 Judge Claire C. Cecchi.
                  ______________________

                   Decided: July 1, 2020
                  ______________________

     CONSTANTINE L. TRELA, JR., Sidley Austin LLP, Chi-
 cago, IL, argued for plaintiffs-appellees. Also represented
 by STEVEN J. HOROWITZ; VERNON M. WINTERS, San Fran-
 cisco, CA; JOSHUA JOHN FOUGERE, JEFFREY PAUL KUSHAN,
 Washington, DC; JAMES ASA HIGH, JR., Amgen Inc., South
 San Francisco, CA; DREW DIAMOND, JOSEPH E. LASHER,
 DENNIS J. SMITH, WENDY A. WHITEFORD, Thousand Oaks,
Case: 20-1037         Document: 97    Page: 2   Filed: 07/01/2020

 2                                 IMMUNEX CORP.   v. SANDOZ, INC.

 CA.

    WILLIAM M. JAY, Goodwin Procter LLP, Washington,
 DC, argued for defendants-appellants. Also represented by
 BRIAN TIMOTHY BURGESS; CINDY CHANG, New York, NY;
 GERARD JUSTIN CEDRONE, DAVID ZIMMER, Boston, MA; DAN
 HOANG, GEORGE C. LOMBARDI, MAUREEN L. RURKA, JULIA
 MANO JOHNSON, Winston & Strawn LLP, Chicago, IL.

     MATTHEW S. HELLMAN, Jenner & Block LLP, Washing-
 ton, DC, for amicus curiae Association for Accessible Med-
 icines. Also represented by ADAM G. UNIKOWSKY; YUSUF
 ESAT, Chicago, IL; JEFFREY FRANCER, The Association for
 Accessible Medicines, Washington, DC.

     JOHN CAMERON ADKISSON, Fish & Richardson PC, Min-
 neapolis, MN, for amicus curiae Samsung Bioepis Co., Ltd.
 Also represented by ELIZABETH M. FLANAGAN, DEANNA
 JEAN REICHEL; JONATHAN ELLIOT SINGER, San Diego, CA.
                  ______________________

      Before O’MALLEY, REYNA, and CHEN, Circuit Judges.
     Opinion for the court filed by Circuit Judge O’MALLEY.
           Dissenting opinion filed by Circuit Judge REYNA.
 O’MALLEY, Circuit Judge.
     Patent owner Hoffmann-La Roche Inc. (“Roche”), its ex-
 clusive licensee Immunex Corp., and exclusive sublicensee
 Amgen Manufacturing, Ltd., initiated this patent infringe-
 ment suit pursuant to the Biologics Price Competition and
 Innovation Act (“BPCIA”). 1       Sandoz, Inc., Sandoz

       1 Immunex Corp. and Amgen Manufacturing, Ltd.
 are collectively referred to as “Immunex.” Although Roche
 joined the district court litigation, it did not enter an ap-
 pearance in this appeal.
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 IMMUNEX CORP.    v. SANDOZ, INC.                           3

 International GmbH, and Sandoz GmbH filed abbreviated
 Biologics License Application (“aBLA”) No. 761042. 2 This
 action followed shortly thereafter. In the aBLA, Sandoz
 sought approval to market Erelzi, a biosimilar version of
 Immunex’s biologic drug, Enbrel®.
     Enbrel® is covered by the patents-in-suit: U.S. Patent
 Nos. 8,063,182 (“’182 patent”) and 8,163,522 (“’522 pa-
 tent”). Prior to trial, Sandoz stipulated to infringement of
 the asserted claims of the patents-in-suit. After a two-
 week bench trial, the United States District Court for the
 District of New Jersey entered final judgment for Immunex
 and Roche, holding that Sandoz had failed to prove that the
 asserted claims of the patents-in-suit were invalid.
     Sandoz appeals from the district court’s judgment. On
 appeal Sandoz argues, as it did before the district court,
 that the patents-in-suit are invalid for (1) obviousness-type
 double patenting; (2) failure to meet the written descrip-
 tion requirement; and (3) obviousness. For the reasons dis-
 cussed below, we affirm.
                        I. BACKGROUND
         A. The Claimed Technology and Patents-in-Suit
     The patents-in-suit are directed to the fusion protein
 etanercept and methods of making the same. Etanercept
 is the active ingredient in Immunex’s biologic drug
 Enbrel®, which is primarily indicated for reducing the
 signs and symptoms of moderately to severely active rheu-
 matoid arthritis, an autoimmune disorder. Etanercept is
 made by combining a portion of a 75 kilodalton (“kDa”) hu-
 man tumor necrosis factor receptor protein with a portion
 of immunoglobulin G1 (“IgG1”).

     2  Sandoz, Inc., Sandoz International GmbH, and
 Sandoz GmbH are collectively referred to as “Sandoz.”
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 4                              IMMUNEX CORP.   v. SANDOZ, INC.

      IgG1 is a type of antibody. Antibodies are proteins de-
 ployed by the immune system to identify and neutralize
 foreign objects—such as bacteria and viruses—called anti-
 gens. Each antibody contains a region that binds to a por-
 tion of an antigen. Through this binding mechanism, an
 antibody can either neutralize the target antigen directly—
 for example, by blocking the part of a virus that is essential
 for the survival of the virus—or tag a microbe or an infected
 cell for attack by other parts of the immune system. Like
 all proteins, antibodies are made up of amino acids con-
 nected to form chains called polypeptides. The polypep-
 tides fold into three-dimensional structures that impart
 structural and functional characteristics to the antibodies.
      Structurally, each antibody (including IgG1) consists of
 four chains of amino acids: two identical “heavy chains”
 and two identical “light chains,” arranged in a Y-shape. All
 four chains in the antibody contain two different segments:
 a constant region (denoted by CH for the heavy chain con-
 stant region and CL for the light chain constant region) and
 a variable region (VH for the heavy chain variable region
 and VL for the light chain variable region). The variable
 regions are segments of the antibody that determine
 whether, and how effectively, an antibody will bind to a
 given antigen. The constant regions, on the other hand,
 interact with other components of the immune system
 through “domains”—areas of the protein that have a spe-
 cific structure and can serve a specific function. The light
 chain constant region consists of the CL domain. The
 heavy chain constant region includes the CH1, the hinge,
 CH2, and CH3 domains.
      The human immune system also contains cytokines—
 cell signaling proteins that effectuate a variety of immune
 responses. Tumor necrosis factor (“TNF”) is one type of cy-
 tokine produced in the human body. It is associated with
 autoimmune inflammatory diseases such as rheumatoid
 arthritis. TNF binds to TNF receptors (“TNFRs”), trans-
 membrane receptors that contain three distinct regions:
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 IMMUNEX CORP.   v. SANDOZ, INC.                            5

 intracellular, transmembrane, and extracellular. There
 are two types of TNFRs, p55 (a 55 kDa protein) and p75 (an
 approximately 75 or 80 kDa protein). The extracellular re-
 gion of TNFRs binds to TNF. This region can be split off to
 make a soluble protein that binds to TNF, allowing for re-
 moval or neutralizing of excess TNF from the body.
     Etanercept—a fusion of the extracellular region of p75
 and the hinge-CH2-CH3 portion of the constant region of
 the IgG1 heavy chain—binds to excess TNF and neutral-
 izes it. In this way, it reduces the autoimmune inflamma-
 tory response in patients with rheumatoid arthritis.
     The claims of the ’182 patent are directed to etanercept,
 and the claims of the ’152 patent are directed to methods of
 making etanercept. Both patents-in-suit claim priority to
 European Patent Application No. 90116707.2 (“the EP ’707
 Application”), filed on August 31, 1990, and U.S. Applica-
 tion No. 07/580,013 (“the ’013 Application”), filed on Sep-
 tember 10, 1990. Roche, the party that originally filed the
 applications in this patent family, abandoned the ’013 Ap-
 plication, but filed a continuation, U.S. Application No.
 08/965,640 (“the ’640 Application”) on July 21, 1993. This
 application was subject to a restriction requirement by the
 United States Patent and Trademark Office (“USPTO”).
 As a result of the restriction requirement, on May 19, 1995,
 Roche filed two divisional applications claiming priority to
 the ’640 application. These applications matured into the
 ’182 and ’152 patents, which issued on November 22, 2011
 and April 24, 2012, respectively.
                B. License Agreements Between
                     Immunex 3 and Roche
     To understand the parties’ arguments on appeal, a
 basic understanding of the historical relationship between

     3  For simplicity, we refer to the licensee of the pri-
 mary agreement at issue as “Immunex,” because all rights
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 6                             IMMUNEX CORP.   v. SANDOZ, INC.

 Immunex and Roche, as well as certain licenses between
 them, is necessary. By 1990, both Roche and Immunex
 Corp. were separately engaged in researching TNF and in-
 vestigating whether targeting this molecule could provide
 any therapeutic benefits. In April 1990, Roche published
 the complete amino acid sequence of the p55 TNFR. In
 May 1990, Immunex Corp. published an article containing
 the full amino acid sequence of the p75 TNFR. And, in July
 1990, Roche published the complete amino acid sequence
 of p75, along with part of its encoding DNA. As noted
 above, it was Roche that filed the priority application for
 the patents-in-suit in 1990, as well as the applications for
 the patents-in-suit in 1995.
     Immunex Corp., working independently on TNFR-IgG
 fusion proteins, obtained FDA approval of Enbrel® in 1998.
 Almost a year later, Immunex Corp. and Roche entered
 into a license (the “Immunex-Roche agreement”), effective
 as of the approval date of Enbrel®, pursuant to which Im-
 munex obtained a license to, inter alia, the EP ’707 Appli-
 cation and the ’013 Application, and all patents that issue
 from those applications. J.A. 25867. Immunex agreed to
 pay Roche royalties on the sales of Enbrel®. J.A. 25876–
 80.
     In 2002, non-party Amgen, Inc. acquired Immunex
 Corp. Subsequently, in 2004, Amgen, Inc., Immunex Corp.,
 Roche, and non-party Wyeth entered into an “Accord & Sat-
 isfaction” agreement concerning the same patent family.
 J.A. 25836. The purpose of the agreement was “to elimi-
 nate the continuing obligations to pay royalties to Roche”
 pursuant to the Immunex-Roche agreement. Id.

 initially granted to the original licensee, Amgen, Inc., and
 its affiliates were ultimately consolidated in Immunex
 Corp.
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 IMMUNEX CORP.   v. SANDOZ, INC.                            7

     Under the terms of the Accord & Satisfaction, Im-
 munex has a paid-up, irrevocable, exclusive license to the
 U.S. patent family for the patents-in-suit. It has the sole
 right to grant sublicenses, to make, have made, use, sell,
 offer for sale and import products covered by the patent
 family. J.A. 25839. With respect to patent prosecution,
 Immunex has the exclusive right to prosecute patent appli-
 cations in the U.S. patent family. J.A. 25840. Thus, as of
 2004, Immunex controlled the prosecution of the patents-
 in-suit.
      Under the terms of the agreement, Immunex has the
 first right to rectify any suspected infringement of the li-
 censed patent family at its sole expense and under its sole
 control, by instituting suit or by sublicense. And, Immunex
 may retain the entirety of any award of damages or lost
 profits resulting from such an infringement suit. Roche is
 obligated to cooperate in any such suit, including by partic-
 ipating as a party to the extent required by the court in
 order to bring suit. Id. Immunex also has the right to an
 assignment of the patents-in-suit upon request and upon
 the payment of $50,000. Id. (“If requested . . . Roche shall
 execute an assignment of” the patents). 4
      Under the terms of the Accord & Satisfaction, Roche is
 required to cooperate with Immunex regarding prosecution
 and enforcement of the patents-in-suit, including by
 providing evidence and testimony in connection with any
 proceeding affecting the validity of the patents-in-suit. Id.
 Roche also retains the right to practice the patents for in-
 ternal, non-clinical research only. In addition, Roche re-
 tains the secondary right, but not obligation, to sue if
 Immunex fails to rectify infringement or initiate an action
 for such infringement within 180 days after written notifi-
 cation by Roche. The agreement further provides that,

     4  By contrast, non-party Wyeth obtained an assign-
 ment of the European patents in the patent family.
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 8                              IMMUNEX CORP.    v. SANDOZ, INC.

 once Roche’s secondary right to sue is triggered, Roche
 may, at its sole expense and under its sole control and di-
 rection, initiate suit and may retain the entirety of any
 award of damages or lost profits as a result of such suit.
 J.A. 25841.
                    C. Procedural History
      In February 2016, Immunex, together with Roche, filed
 this patent infringement action against Sandoz under the
 BPCIA. The district court held a two-week bench trial in
 September 2018. Sandoz did not contest infringement of
 the ’182 and ’522 patents. Accordingly, the only issues be-
 fore the district court at trial were the validity of the as-
 serted claims of the patents-in-suit. Specifically, the
 district court considered whether claims 11–12 and 35–36
 of the ’182 patent, and claims 3, 8, and 10 of the ’522 patent
 were invalid for lack of written description and enable-
 ment; obvious in light of certain asserted prior art refer-
 ences; and invalid for obviousness-type double patenting.
     On August 9, 2019, in a detailed opinion, the district
 court issued its findings of fact and conclusions of law, hold-
 ing that Sandoz had not proven that the patents-in-suit
 were invalid. Immunex Corp. v. Sandoz Inc., 395 F. Supp.
3d 366, 374 (D.N.J. 2019). The court entered final judg-
 ment for Immunex and Roche on October 8, 2019. Sandoz
 timely appeals. We have jurisdiction pursuant to 28 U.S.C.
 § 1295(a).
                        II. DISCUSSION
     On appeal, Sandoz argues that the patents-in-suit are
 invalid for (1) obviousness-type double patenting; (2) fail-
 ure to meet the written description requirement; and (3)
 obviousness. We address each issue in turn.
                   A. Standards of Review
     Following a bench trial, we review a district court’s con-
 clusions of law without deference and its findings of fact for
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 IMMUNEX CORP.   v. SANDOZ, INC.                             9

 clear error. Ferring B.V. v. Watson Labs., Inc.-Fla., 764
F.3d 1401, 1406 (Fed. Cir. 2014). “A factual finding is
 clearly erroneous if, despite some supporting evidence, we
 are left with the definite and firm conviction that a mistake
 has been made.” Id.
          B. Obviousness-Type Double Patenting
      Obviousness-type double patenting is a judicially-cre-
 ated doctrine aimed at preventing claims in separate pa-
 tents that claim obvious variants of the same subject
 matter where “granting both exclusive rights would effec-
 tively extend the life of patent protection.” In re Hubbell,
 709 F.3d 1140, 1145 (2013) (quotations omitted); Eli Lilly
 and Co. v. Barr Labs., Inc., 251 F.3d 955, 967 (Fed. Cir.
 2001) (“The judicially-created doctrine of obviousness-type
 double patenting . . . prohibit[s] a party from obtaining an
 extension of the right to exclude through claims in a later
 patent that are not patentably distinct from claims in a
 commonly owned earlier patent.”). The doctrine applies to
 all commonly-owned patents, even in cases where the obvi-
 ous variants are invented by different inventors. In re
 Longi, 759 F.2d 887, 895 (Fed. Cir. 1985). As we have pre-
 viously recognized, there are two justifications for this doc-
 trine: (1) to prevent timewise extension of the right to
 exclude; and (2) to prevent multiple infringement suits by
 different assignees. Hubbell, 709 F.3d at 1145. “[T]he ul-
 timate conclusion that a patent is invalid under the doc-
 trine of obviousness-type double patenting is reviewed de
 novo.” Novartis Pharm. Corp. v. Breckenridge Pharm. Inc.,
 909 F.3d 1355, 1361 (Fed. Cir. 2018). “[P]redicate findings
 of fact” are reviewed for clear error. Eli Lilly & Co. v. Teva
 Parenteral Medicines, Inc., 689 F.3d 1368, 1376 (Fed. Cir.
 2012).
     At trial, Sandoz asserted that the patents-in-suit are
 invalid for obviousness-type double patenting over several
 patents filed by Immunex Corp. in the years leading up to
 and shortly after the approval of Enbrel®. The district
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 10                             IMMUNEX CORP.    v. SANDOZ, INC.

 court rejected Sandoz’s contentions, finding in favor of Im-
 munex on several layers of analysis: (1) that Sandoz’s pro-
 posed test for common-ownership does not apply; (2) even
 if that test applies, the patents-in-suit and the asserted
 double-patenting reference patents are not commonly
 owned; (3) even if they are commonly owned, the two-way,
 rather than the one-way test for obviousness-type double
 patenting applies as to some of the double-patenting refer-
 ences; and (4) the patents-in-suit are patentably distinct
 from each of the asserted double patenting references. On
 appeal, Sandoz limits its arguments to two patents, U.S.
 Patent Nos. 7,915,225 (“Finck ’225”) and 5,605,690 (“Ja-
 cobs ’690”) (collectively, the “Immunex Patents”). It con-
 cedes that it must prevail at each step of the district court’s
 analysis to garner a reversal of the court’s decision regard-
 ing obviousness-type double patenting; losing at any one of
 these steps is fatal to Sandoz’s arguments. Oral Arg. at
 1:23–54, available at http://oralarguments.cafc.uscourts.g
 ov/default.aspx?fl=2020-1037.mp3) (“[Counsel for Appel-
 lant:] I agree that there are multiple steps that we would
 ask this court to take.”).
     As to the first step of the court’s analysis, in a novel
 theory of common ownership, Sandoz argues that, even
 though the patents-in-suit are assigned to Roche, Immunex
 effectively owns both the Immunex Patents and the pa-
 tents-in-suit because all substantial rights in the patents-
 in-suit transferred to Immunex pursuant to the Accord &
 Satisfaction. Borrowing from our 35 U.S.C. § 281 case law,
 Sandoz argues that an agreement that conveys “all sub-
 stantial rights” in a patent is tantamount to an assignment
 of ownership. Appellants’ Br. 27–28 (citing Morrow v. Mi-
 crosoft Corp., 499 F.3d 1332, 1340 (Fed. Cir. 2007)). In
 Sandoz’s view, this “all substantial rights” test—to date
 used only to determine who may sue for infringement as a
 “patentee” pursuant to 35 U.S.C. § 281—should apply in
 the obviousness-type double patenting context as well.
 And, Sandoz contends, the relevant agreement here
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 IMMUNEX CORP.   v. SANDOZ, INC.                            11

 transferred all substantial rights in the patents-in-suit to
 Immunex.
     As discussed below, although we agree with Sandoz
 that the “all substantial rights” test can be informative in
 determining common ownership in the obviousness-type
 double patenting context, we conclude that the agreement
 at issue here did not transfer all substantial rights from
 the assignee, Roche, to the exclusive licensee, Immunex.
 Accordingly, we need not address the other layers of the
 district court’s detailed analysis on obviousness-type dou-
 ble patenting.
             1. The All Substantial Rights Test
      Under Sandoz’s theory of common ownership, if a party
 is the effective patentee for purposes of the ability to bring
 an infringement suit, then it is also an effective patentee
 for purposes of obviousness-type double patenting. Sandoz
 contends that a contrary rule would allow circumvention of
 patent term limitations by simply reclassifying an assign-
 ment as a license. Appellants’ Br. 28–29. And, Sandoz ar-
 gues, if a party acquires all substantial rights in a patent
 application, including the right to control prosecution, then
 obviousness-type double patenting should apply to prohibit
 issuance of claims that are not patentably distinct from
 claims in patents already owned by that party. Appellants’
 Reply Br. 9.
     Immunex responds that common ownership-based ob-
 viousness-type double patenting arises only where the rel-
 evant inventions were owned by the same entity at the time
 of the invention. Appellees’ Br. 36. Immunex cites to the
 Manual of Patent Examining Procedure (“MPEP”), which
 states that “[a]pplications or patents are ‘commonly owned’
 pursuant to 35 U.S.C. 102(b)(2)(C) or pre-AIA 35 U.S.C.
 103(c)(1) if they were wholly or entirely owned by the same
 person(s), or organization(s)/business entity(ies), at the
 time the claimed invention was filed or made, respec-
 tively.” Id. at 37 (quoting MPEP § 804.03(II)). In
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 12                             IMMUNEX CORP.   v. SANDOZ, INC.

 Immunex’s view, this test applies because common owner-
 ship in the obviousness-type double patenting context “ex-
 ists to fill a narrow statutory gap,” created by the Patent
 Law Amendments of 1984, Pub. L. No. 98-622, § 104, 98
 Stat. 3383 (“the 1984 Act”). Id. at 37–38 (citing 1984 Act
 (codified in 35 U.S.C. § 103(c))). Prior to the 1984 Act, Im-
 munex argues, the USPTO recognized that common own-
 ership-based      double     patenting     rejections   were
 unnecessary, because examiners could simply use anticipa-
 tion or obviousness rejections to avoid issuing multiple pa-
 tents claiming the same invention or obvious variants. Id.
 at 37 (citing Commissioner’s Notice on Double Patenting,
 834 O.G. 1615, 1616 (Jan. 9, 1967)). But the 1984 Act pro-
 hibited rejections based on prior art owned by the same
 person or subject to an obligation of assignment to the same
 person. Id. at 37–38 (citing 1984 Act). Immunex argues
 that Congress expected double patenting to fill the gap
 where the USPTO could no longer rely on §§ 102 and 103
 to avoid issuing multiple patents on the same invention in
 cases involving common ownership. Id. at 37–38. Accord-
 ing to Immunex, the MPEP’s test for common ownership is
 “narrowly tailored to close the gap created by the 1984 Act.”
Id. at 39.
     We have previously rejected Immunex’s reading of the
 history of the 1984 Act. See In re Longi, 759 F.2d 887, 893
 (Fed. Cir. 1985). In Longi, rejecting the argument that ob-
 viousness-type double patenting should not apply to com-
 monly-owned applications with different inventive entities,
 we ruled that such a broad proposition was inconsistent
 with recent legislation, i.e., the 1984 Act. Id. We explained
 that we have never endorsed the Commissioner’s Notice on
 which Immunex now relies because the notice was merely
 a procedural memorandum and, importantly, was incon-
 sistent with many of our predecessor court’s decisions. Id.
 at 894. Indeed, directly refuting Immunex’s arguments is
 our express acknowledgement in Longi that common own-
 ership-based obviousness-type double patenting existed
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 even before 1984. Id. at 893; see also In re Rogers, 394 F.2d
566, 569 (C.C.P.A. 1968). Examining the very 1984 Act
 that, in Immunex’s view, created a “statutory gap” that
 common ownership-based obviousness-type double patent-
 ing is designed to close, we said that the Act seemed “not
 intended to affect the doctrine of double patenting, but
 seem[ed] rather to reaffirm its viability.” Longi, 759 F.2d
 at 895. Thus, we have already considered and rejected Im-
 munex’s argument that common ownership-based obvious-
 ness-type double patenting is a narrow gap-filling rule in
 response to the 1984 Act.
     Immunex’s “time of invention” test is also inconsistent
 with more recent case law. For example, we have applied
 common ownership-based obviousness-type double patent-
 ing where a party “merged with the original assignees of”
 the double-patenting references at issue. Geneva Pharm.,
 Inc. v. GlaxoSmithKline PLC, 349 F.3d 1373, 1377, 1386
 (Fed. Cir. 2003). And, although the Board of Patents Ap-
 peals and Interferences (“BPAI”), predecessor to the Patent
 Trial and Appeals Board, applied the MPEP definition of
 “common ownership” (from the 35 U.S.C. § 103(c) context)
 to double patenting cases, it expressly did not do so with
 respect to the timing of the invention. Ex Parte Maurice,
 No. 2005-2463, 2005 WL 4779419, at *2 (B.P.A.I. Sept. 19,
 2005). In Ex Parte Maurice, while accepting that “com-
 monly owned” for double patenting purposes must be read
 to be consistent with common ownership in the context of
 35 U.S.C. § 103(c), the BPAI clarified that “[b]y ‘consistent,’
 appellants presumably mean consistent with regard to the
 required interest of each co-owner, and not necessarily con-
 sistent in terms of the time frame in which ownership is
 considered.” Id.
      We see no justification for applying Immunex’s “time of
 filing” requirement in the obviousness-type double patent-
 ing context. Indeed, adopting Immunex’s rule might lead
 to the absurd result where, even if originally applied for by
 inventors working under an obligation of future
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 14                              IMMUNEX CORP.   v. SANDOZ, INC.

 assignment to an employer, patents may not be considered
 “commonly owned” because, at the “time of invention,” the
 assignment had not been effectuated. Such a result would
 effectively eviscerate common ownership-based obvious-
 ness-type double patenting. Accordingly, we conclude that
 Immunex’s “time of filing” test for common ownership does
 not apply.
     By contrast, Sandoz’s proposed test for common owner-
 ship—determining whether a party controlling prosecution
 was the “effective patentee” under the “all substantial
 rights” test—appears consistent with both principles un-
 derlying obviousness-type double patenting, namely, pre-
 venting unjustified patent term extensions and preventing
 harassment from multiple suits. Applying Sandoz’s test
 would prevent an effective patentee from unjustifiably ex-
 tending its patent term by using the nominal label of licen-
 see. The second consideration underlying obviousness-type
 double patenting—preventing harassment through multi-
 ple infringement suits by different assignees asserting es-
 sentially the same patented invention—also undergirds
 our 35 U.S.C. § 281 jurisprudence. See Hubbell, 709 F.3d
 at 1145; see also Lone Star Silicon Innovations LLC v.
 Nanya Tech. Corp., 925 F.3d 1225, 1233 (Fed. Cir. 2019).
      We are mindful, however, of the existing complexities
 in applying the equitable doctrine of obviousness-type dou-
 ble patenting and see no reason to import into this judi-
 cially-created doctrine the entirety of our body of law
 analyzing who is a statutory “patentee” pursuant to 35
 U.S.C. § 281. We conclude only that where one of the rights
 transferred is the right to prosecute the patent at issue, iden-
 tification of the effective “patentee” is informative in eval-
 uating whether the patents are “commonly owned” for
 purposes of obviousness-type double patenting. Where, as
 here, a party ultimately controls prosecution of both sets of
 patents, the “all substantial rights” test aids in preventing
 the unjustifiable issuance of claims that are patentably in-
 distinct from claims already owned by that party. Under
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 these circumstances, looking to the “all substantial rights”
 test achieves the proper balance between deterring games-
 manship in prosecution, on the one hand, and avoiding any
 chilling effect on routine collaborations and licensing be-
 tween parties working in the same field of research, on the
 other.
           2. The Accord & Satisfaction Did Not
           Transfer All Substantial Rights in the
               Patents-in-Suit to Immunex
     We now turn to the agreement at issue, and whether,
 as Sandoz argues, it is effectively an assignment because it
 transferred all substantial rights in the patents-in-suit to
 Immunex. “To determine whether an exclusive license is
 tantamount to an assignment, we must ascertain the in-
 tention of the parties to the license agreement and examine
 the substance of what was granted.” Alfred E. Mann
 Found. v. Cochlear Corp., 604 F.3d 1354, 1359 (2010) (al-
 terations and quotations omitted); see also Vaupel Textil-
 maschinen KG v. Meccanica Euro Italia S.P.A., 944 F.2d
870, 874 (Fed. Cir. 1991). The focus is on the substance of
 what was granted. Id. We have recently reaffirmed that
 “we examine the ‘totality’ of the agreement to determine
 whether a party other than the original patentee has es-
 tablished that it obtained all substantial rights in the pa-
 tent.” Lone Star, 925 F.3d at 1229; Prima Tek II, LLC v.
 A-Roo Co., 222 F.3d 1372 (Fed. Cir. 2000). Although we
 have “never purported to establish a complete list of the
 rights [that can] . . . render an exclusive licensee the owner
 of a patent,” Alfred E. Mann, 604 F.3d at 1360, “we have
 often focused on two salient rights: enforcement and alien-
 ation,” Lone Star, 925 F.3d at 1231. Thus, we have consid-
 ered factors such as the scope of the licensee’s right to
 sublicense, the nature of license provisions regarding re-
 version of rights, the duration of the license grant, and the
 nature of any limits on the licensee’s right to assign its in-
 terests in the patent.” Alfred E. Mann, 604 F.3d at 1360–
 61.
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 16                             IMMUNEX CORP.    v. SANDOZ, INC.

      As a threshold matter, the parties dispute the applica-
 ble standard of review. Sandoz argues that de novo review
 applies to this determination, whereas Immunex main-
 tains that also at issue is the district court’s factual deter-
 mination of the parties’ intent, which should be reviewed
 deferentially. Appellants’ Reply Br. 11–12; Appellees’ Br.
 47–48. As we explained in Alfred E. Mann, the substance
 of what was granted is determined by interpreting the li-
 cense. 604 F.3d at 1359. Here, the contract is governed by
 Delaware law, which provides that the district court’s in-
 terpretation presents a question of law to be reviewed de
 novo. In re Viking Pump, Inc., 148 A.3d 633, 643–44 (Del.
 2016). As to the question of whether the provisions effec-
 tuated a transfer of all substantial rights such that Im-
 munex, not Roche, is the “patentee,” that is a legal question
 we review de novo under our own law. Prima Tek, 222 F.3d
 at 1377. But, to the extent determining the intention of the
 parties requires evaluation of parol evidence, that “evalua-
 tion presents a question of fact that we review deferen-
 tially.” Alfred E. Mann, 604 F.3d at 1359.
      The district court treated this as a two-part inquiry,
 looking first to the parties’ intent and then to the agree-
 ment provisions to determine “the substance of what was
 granted.” Immunex, 395 F. Supp. 3d at 415–17. The court
 found that Roche and Immunex “specifically intended for
 the Accord & Satisfaction to be a license such that Roche
 would remain the owner of the patents-in-suit.” Id. at 415.
 It looked to “the face of the [agreement] itself,” which calls
 the grant to Immunex a “license.” Id. at 416. The court
 also relied on the testimony of an Amgen corporate witness
 to conclude that the parties intended for the agreement to
 be a license. Id.
     Absent ambiguous provisions, however, there is no
 need to resort to parol evidence to determine the parties’
 intent. The court did not find that the Accord & Satisfac-
 tion was ambiguous. Accordingly, it should not have made
 any factual determinations regarding the intent of the
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 IMMUNEX CORP.   v. SANDOZ, INC.                             17

 parties as shown by witness testimony. 5 As to the fact that
 the agreement is called a “license,” we have clarified that
 “whether a transfer of a particular right or interest under
 a patent is an assignment or a license does not depend upon
 the name by which it calls itself, but upon the legal effect of
 its provisions.” Lone Star, 925 F.3d at 1230 (emphasis in
 original) (quoting Waterman v. Mackenzie, 138 U.S. 252,
 256 (1891)). Here, it does not matter that the grant to Im-
 munex was titled a “license”—what matters is the effect of
 the agreement on the parties’ respective rights. Indeed, in
 arguing for a deferential standard of review, Immunex
 cites to no cases where we have looked beyond the contract
 at issue to determine the parties’ intent. We therefore look
 only to the substance of what was transferred under the
 Accord & Satisfaction, which we review de novo.
      Review of the 2004 Accord & Satisfaction reveals the
 following: Section 3.5 of the agreement gives Immunex the
 first right to rectify any suspected infringement, at Im-
 munex’s sole expense and under its sole control, by insti-
 tuting suit or by sublicensing the patents. J.A. 25840.
 Immunex may retain the entirety of any award of damages
 or lost profits as a result of such suit. Roche is required to
 cooperate in any Immunex-initiated infringement suit, in-
 cluding by participating as a party only to the extent re-
 quired by the court in order to bring suit. But, under
 Section 3.6, Roche retains the secondary right to sue if Im-
 munex fails to rectify any infringement within 180 days af-
 ter written request by Roche. J.A. 25841. After this 180-
 day notice period, Roche may, at its sole expense and under
 its sole control and direction, initiate suit. Id. Roche may

     5   The dissent likewise points to witness testimony in
 support of its conclusion that Roche transferred all sub-
 stantial rights in the patents-in-suit to Immunex. Dissent
 Op. at 5–6. We do not think the analysis in this case should
 be guided by parol evidence.
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 18                             IMMUNEX CORP.    v. SANDOZ, INC.

 retain the entirety of any award of damages or lost profits
 as a result of a Roche-initiated suit. Immunex further has
 a duty to cooperate in such a Roche-initiated suit. Notably,
 “the right to rectify infringement under . . . Section 3.6 is
 solely with” Roche. Id. As to alienation rights, under Sec-
 tion 11.4, neither party may assign its rights to third par-
 ties without the written consent of the other. J.A. 25849.
     On appeal, Sandoz argues that these provisions, taken
 together, effectuated a transfer of all substantial rights
 from Roche to Immunex. Sandoz points to Immunex’s
 “paid-up, irrevocable, exclusive license” and “first right to
 rectify any alleged infringement” on the one hand, and
 Roche’s loss of control over licensing and litigation activi-
 ties on the other, to argue that Roche was “stripped of any
 of the traditional attributes of ownership.” Appellants’ Br.
 31–32. Sandoz also contends that Immunex’s ability to
 drive the prosecution of the patents is another indication
 that Roche transferred all substantial rights.
     Immunex responds that Roche is still the effective pa-
 tentee because it retained several key rights under the Ac-
 cord & Satisfaction. Immunex points to: (1) Roche’s
 secondary right to sue; (2) Roche’s right to practice the pa-
 tents for internal, non-clinical research; (3) Immunex’s op-
 tion to convert the license into an assignment by paying an
 additional consideration of $50,000; and (4) Roche’s right
 to veto the assignment of Immunex’s interest under the
 agreement to any unrelated party. Appellees’ Br. 49–53.
      The enforcement and alienation rights under the Ac-
 cord & Satisfaction make clear that Roche did not transfer
 all substantial rights in the patents to Immunex. We have
 explained that the nature and scope of the licensee’s right
 to sue, together with the nature of the licensor’s retained
 right to sue, is “[f]requently . . . the most important consid-
 eration.” Alfred E. Mann, 604 F.3d at 1361. Here, alt-
 hough Immunex obtained the first right to sue, Roche
 retained the secondary right to sue. Like the license at
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 issue in Alfred E. Mann, although Roche’s “right to choose
 to sue an infringer does not vest until [Immunex] chooses
 not to sue that infringer, [that right] is otherwise unfet-
 tered.” Id. at 1362. Once Roche’s secondary right to sue
 vests, the ability to rectify infringement is “solely” with
 Roche, and may not pass to Immunex. After the 180-day
 notice period, Roche can decide “whether or not to bring
 suit, when to bring suit, where to bring suit, what claims
 to assert, what damages to seek, [and] whether to seek in-
 junctive relief.” Id. Retention of “such broad right[s]” is
 “thoroughly inconsistent” with a conclusion that the pa-
 tents-in-suit were effectively assigned to Immunex. See id.
      Sandoz cites Speedplay, Inc. v. Bebop, Inc., 211 F.3d
1245 (Fed. Cir. 2000), for the proposition that Roche’s sec-
 ondary right to sue is “illusory” because Immunex can “un-
 dercut Roche’s ability to sue by granting a royalty-free
 sublicense to an alleged infringer.” Id. at 33–35 (citing
 Speedplay, 211 F.3d at 1251). In Speedplay, we concluded
 that the licensor’s retained right to sue was illusory be-
 cause the licensee could render that right nugatory by
 granting the alleged infringer a royalty-free sublicense.
211 F.3d at 1251. Sandoz argues that, here, because the
 license is fully paid-up, there are no pass-through royalties,
 just like in Speedplay, rendering the secondary right to sue
 illusory. But, as we have explained, “Speedplay . . . held
 that a licensee’s right to grant royalty-free sublicenses to
 defendants sued by the licensor rendered illusory the licen-
 sor’s right to sue.” Alfred E. Mann, 604 F.3d at 1362 (em-
 phasis added).       That is precisely what the licensee
 Immunex cannot do here: under Section 3.6 of the agree-
 ment, once Roche’s secondary right to sue is triggered, Im-
 munex no longer has any right to rectify any infringement
 and cannot frustrate a Roche-initiated suit by granting a
 royalty-free sublicense to defendants sued by Roche, and
 Roche retains the entirety of any award of damages. We
 reject Sandoz’s contention that Section 3.6 “does not modify
 Immunex’s sublicensing rights.” Appellants’ Reply Br. 13.
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 20                             IMMUNEX CORP.   v. SANDOZ, INC.

 Thus, unlike the licensor in Speedplay, Roche’s secondary
 right to sue is not illusory. 6
      Roche’s right to veto any assignment of Immunex’s in-
 terest in the patents-in-suit also weighs in favor of the con-
 clusion that all substantial rights were not transferred. We
 have previously made clear that restrictions on the ability
 to transfer patent rights are inconsistent with a transfer of
 all substantial rights. Lone Star, 925 F.3d at 1222–23; see
 also Abbott Labs. v. Diamedix Corp., 47 F.3d 1128, 1132
 (Fed. Cir. 1995). Here, under Section 11.4 of the agree-
 ment, Immunex may not assign its rights in the patents-
 in-suit to a third party without Roche’s written consent.
 This restriction on alienation of rights is a further indica-
 tion that Roche transferred less than all substantial rights
 in the patents-in-suit.
     We reject Sandoz’s argument—also relied upon by the
 dissent—that Immunex’s ability to convert the license into
 an assignment upon payment of $50,000 somehow evinces
 a transfer of all substantial rights. See Appellants’ Br. 17;
 Dissent Op. at 5. This option to purchase the patents-in-

      6   Adopting Sandoz’s arguments, the dissent urges
 that “[t]he focus of the Speedplay inquiry is whether a li-
 censee can nullify a licensor’s secondary right to sue, pre-
 or post-suit.” Dissent Op. at 7. But like Sandoz, the dissent
 fails to account for our decision in Alfred E. Mann, where
 we explained that the holding in Speedplay turned on the
 licensee’s ability to frustrate a licensor-initiated suit. See
 Alfred E. Mann, 604 F.3d at 1362. We also highlighted the
 importance of the licensor’s ability to control litigation
 “[o]nce its right to sue an infringer activates.” Id. The dis-
 sent’s singular focus on Immunex’s ability to prevent
 Roche’s secondary right to sue from vesting is, therefore,
 misguided. The proper inquiry must account for the par-
 ties’ respective rights once Roche’s secondary right to sue
 activates.
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 IMMUNEX CORP.   v. SANDOZ, INC.                            21

 suit is merely one provision in the “totality of the transfer
 agreement” that guides our inquiry. See Lonestar, 925 F.3d
 at 1231. The Accord & Satisfaction makes clear that the
 purpose of the agreement was “to eliminate the continuing
 obligations to pay royalties to Roche” pursuant to the Im-
 munex-Roche agreement. J.A. 25836. Under the terms of
 the Accord & Satisfaction, Immunex paid Roche tens of mil-
 lions of dollars as consideration. The additional considera-
 tion for an outright assignment should be viewed in the
 context of the entirety of the agreement. 7
     Given the totality of the Accord & Satisfaction, we hold
 that Roche did not transfer all substantial rights in the pa-
 tents-in-suit to Immunex. As such, the Immunex Patents
 and the patents-in-suit are not “commonly owned,” and ob-
 viousness-type double patenting does not apply. Accord-
 ingly, we decline to address Sandoz’s remaining arguments
 regarding obviousness-type double patenting. 8 We thus af-
 firm the district court on this point. 9

     7    We are likewise unpersuaded by Sandoz’s argu-
 ment that Roche cannot terminate the agreement once it
 has received payment. Appellants’ Br. 17; see also Dissent
 Op. at 5. This argument overlooks the fact that Immunex’s
 ability to terminate the agreement is also restricted. Even
 though Immunex has the right to terminate the Accord &
 Satisfaction, several provisions of the agreement survive
 any such termination, including § 3.6, which governs
 Roche’s secondary right to sue.
     8    We note, however, that contrary to the dissent’s
 view that the record here demonstrates “gamesmanship in
 prosecution,” Dissent Op. at 3, we see no clear error in the
 district court’s finding that Immunex “acted in good faith
 to diligently prosecute” the patents-in-suit. Immunex, 395
F. Supp. 3d. at 421.
     9    To the extent the district court considered parol ev-
 idence, we consider this harmless error.
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 22                               IMMUNEX CORP.   v. SANDOZ, INC.

                     B. Written Description
     “Written description is a question of fact, judged from
 the perspective of one of ordinary skill in the art as of the
 relevant filing date.” Falko-Gunter Falkner v. Inglis, 448
F.3d 1357, 1363 (Fed. Cir. 2006). The written description
 test involves “an objective inquiry into the four corners of
 the specification from the perspective of a person of ordi-
 nary skill in the art. Based on that inquiry, the specifica-
 tion must describe an invention understandable to that
 skilled artisan and show that the inventor actually in-
 vented the invention claimed.” Ariad Pharm., Inc. v. Eli
 Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010). As a
 question of fact, written description is “to be reviewed un-
 der the clearly erroneous standard.” Vas-Cath Inc. v. Ma-
 hurkar, 935 F.2d 1555, 1563 (Fed. Cir. 1991).
      On appeal, Sandoz argues that the district court erred
 in concluding that the priority application for the patents-
 in-suit disclosed possession of the claimed invention. Spe-
 cifically, Sandoz argues that the priority application did
 not include written description support for (1) the full-
 length p75 DNA sequence; and (2) the claimed p75-IgG1
 fusion protein. We disagree with Sandoz on both points.
                1. The ’013 Application Disclosed
                         Full-Length p75
     According to Sandoz, the ’013 Application described a
 fusion protein based on the truncated/mutated p75 DNA
 sequence disclosed in Figure 4 of the patent, not the full-
 length p75 sequence used in etanercept. Appellants’ Br.
 50–52. Sandoz contends that the fact that the full-length
 p75 sequence was known in the prior art is of no moment
 because the real issue is exactly which p75 sequence Roche
 had in its possession as of the time of the filing of the pri-
 ority application. Id. at 57. In Sandoz’s view, the district
 court’s finding of adequate written description impermissi-
 bly rests on information outside the patent.
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 IMMUNEX CORP.   v. SANDOZ, INC.                            23

     Immunex responds that sequence identification num-
 bers for p75 are mentioned in the specification, and, as its
 witness testified, those sequences would have led a person
 of skill (“POSA”) to the complete p75 sequence using Gen-
 Bank, a well-known genetic sequence database that houses
 a collection of all publicly available DNA sequences. Ap-
 pellees’ Br. 63–64. Immunex further points to the refer-
 ence in the specification to the Smith 1990 publication,
 which, in its view, would have directed a skilled artisan to
 the full-length p75 sequence.
      We agree with Immunex. It is well-established that a
 patent specification need not re-describe known prior art
 concepts. See Capon v. Eshhar, 418 F.3d 1349, 1357 (Fed.
 Cir. 2005) (“The ‘written description’ requirement must be
 applied in the context of the particular invention and the
 state of the knowledge.”); see also Zoltek Corp. v. United
 States, 815 F.3d 1302, 1308 (Fed. Cir. 2016) (“The written
 description need not include information that is already
 known and available to the experienced public.”)). Operat-
 ing under the guidance of these principles, the district
 court properly concluded that the inventors possessed the
 full-length p75 DNA sequence. The specification identifies
 both p55 and p75 TNFRs. And, as the district court noted,
 it “embraces allelic variants and DNA sequences resulting
 from deletions, substitutions, and additions of one or more
 nucleotides of the sequences provides in Figures 1 and/or
 Figure 4.” Immunex, 395 F. Supp. 3d. at 382 (citing ’182
 patent, 4:1–5:24). Example 6 of the specification explains
 that the inventors isolated the 75 kDa full-length p75
 TNFR. Id. at 385 (citing ’182 patent, 15:30–39). We see no
 error in the district court’s reliance on these disclosures to
 conclude that the inventors possessed full-length p75, not
 just the truncated p75 disclosed in Figure 4.
     Importantly, the district court also found that the p75
 sequence was known to a POSA at the time of the inven-
 tion. Id. According to the district court, the Smith 1990
 article, referenced in the priority application, shows that a
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 24                              IMMUNEX CORP.   v. SANDOZ, INC.

 POSA would have known the entire p75 sequence at the
 time of the invention. The Smith 1990 article guided a
 POSA that the “entire nucleotide sequence is available
 upon request and has been deposited with GenBank, acces-
 sion number M32315.” Id. (citing J.A. 26980). And, the
 district court pointed to a July 1990 Roche publication, the
 Dembic article, which also disclosed the entire p75 amino
 acid sequence. Id. The court also credited the testimony of
 Immunex’s expert, who opined that a POSA would have
 been encouraged from the disclosure in the priority appli-
 cation to look to Smith, and therefore, the full-length p75
 protein. Id. at 384. The district court also pointed to the
 two C-terminus and N-terminus p75 sequences disclosed in
 the specification and concluded that, in addition to Figure
 4 and the reference to Smith 1990, these two disclosed se-
 quences would have directed a POSA to the full p75 se-
 quence at the time of the invention. Although Sandoz
 criticizes this finding, the district court credited expert tes-
 timony that a POSA would be led to the complete p75 se-
 quence using these disclosures. Id. Thus, Sandoz’s
 argument that the district court erred by looking outside
 the four corners of the specification or engaged in an “obvi-
 ousness-based” written description analysis is without
 merit. The district court properly considered how a POSA
 would understand the specification.
     As to Sandoz’s arguments that later amendments show
 that the Roche inventors did not have possession of the full
 p75 sequence at the time of invention, the district court cor-
 rectly noted that actual reduction to practice is not re-
 quired to show possession. Immunex, 395 F. Supp. 3d. at
 387–88. The court rejected Sandoz’s arguments that these
 amendments added new matter. We see no error in these
 findings.
     Accordingly, we conclude that the district court did not
 err in finding that the priority application disclosed and
 demonstrated possession of full-length p75.
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 IMMUNEX CORP.   v. SANDOZ, INC.                          25

          2. The ’013 Application Demonstrates
         Possession of the Claimed Fusion Protein
     Sandoz also argues that the priority application did not
 adequately demonstrate possession of the claimed p75-
 IgG1 fusion protein. Sandoz repeats its arguments that the
 Figure 4 truncated sequence was “preferred,” and points
 out that to arrive at the claimed invention, a POSA would
 have had to select the “never-referenced” full Smith se-
 quence. Appellants’ Br. 58–59. Sandoz also argues that
 the specification disclosed a range of immunoglobulin clas-
 ses, and even if the IgG1 and exon-encoded hinge were de-
 scribed as possible options, the priority application
 provided no “blaze marks” that would have led a POSA to
 their selection. Id. at 59. Sandoz’s primary argument is
 that the district court relied on the claims themselves as
 evidence of the “required blaze marks.” Id. at 60.
     Immunex responds that the specification identified
 four preferred fusion proteins, including the claimed p75-
 IgG1 fusion protein, and that Example 11 provided the
 steps required to make these fusion proteins. Appellees’
 Br. 68. And Immunex points to the reference in the speci-
 fication to deposited vectors, which is an adequate descrip-
 tion of the precise IgG1 sequence to be used in the claimed
 fusion proteins. Id. We again agree with Immunex.
     Contrary to Sandoz’s arguments, the district court’s
 written description analysis was not premised on the lan-
 guage of the issued claims. The district court correctly
 noted that the specification refers to the use of deposited
 vectors that contain DNA sequences encoding the exon-de-
 fined hinge-CH2-CH3 region of the human IgG1 heavy
 chain. Immunex, 395 F. Supp. 3d at 386–87. And, the court
 noted that Example 11 teaches how to fuse a soluble TNF-
 binding fragment directly to that hinge-CH2-CH3 region.
Id. at 385 (citing ’182 patent, 9:3–8). Citing expert testi-
 mony, the court concluded that Example 11 discloses this
 concept with p55, and a POSA would have followed that
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 26                             IMMUNEX CORP.   v. SANDOZ, INC.

 example to create etanercept based on the claims and spec-
 ification. Id. Finally, the court noted that “the IgG1 hinge-
 CH2-CH3 was also known in the prior art as of August
 1990.” Id. at 386.
      The district court’s findings are supported by the as-
 filed specification and are not based on the language of the
 issued claims. First, the district court noted that the claim
 language “identifies the requisite elements of the subject
 invention,” but at the same time it concluded that the ex-
 amples further demonstrate that the Roche inventors had
 possession. Id. Second, as Immunex correctly points out,
 the as-filed patent claims included claim 19, which claimed
 a fusion protein of a TNF-binding protein and IgG1 or
 IgG3. Appellees’ Br. 69 (citing J.A. 25129).
     Accordingly, we conclude that the district court’s writ-
 ten description analysis is not clearly erroneous.
                       C. Obviousness
     Obviousness is a question of law reviewed de novo, with
 underlying factual questions reviewed for clear error. Hon-
 eywell Int’l, Inc. v. United States, 609 F.3d 1292, 1297 (Fed.
 Cir. 2010). “The presence or absence of a motivation to
 combine references in an obviousness determination is a
 pure question of fact.” Novartis AG v. Torrent Pharm. Ltd.,
 853 F.3d 1316, 1327 (Fed. Cir. 2017).
      Sandoz appeals the district court’s obviousness analy-
 sis, arguing that (1) the district court’s motivation to com-
 bine analysis erroneously focused on the inventors’
 subjective motivation rather than the claims’ objective
 reach; and (2) the district court’s analysis regarding objec-
 tive indicia of non-obviousness was legally erroneous. As
 explained below, we do not find Sandoz’s arguments per-
 suasive.
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 IMMUNEX CORP.   v. SANDOZ, INC.                           27

                  1. Motivation to Combine
      Sandoz challenges the district court’s finding that a
 POSA would not have been motivated to either select p75
 or to combine it with an immunoglobulin. Appellants’ Br.
 62. The district court concluded that a POSA would be de-
 terred from pursuing the claimed combination by concerns
 of stimulating inflammation and aggregation, the opposite
 effect from that needed to treat inflammatory conditions
 like rheumatoid arthritis. According to Sandoz, this was
 legal error because the claims are not directed to treatment
 of any disease or condition, and because it was known that,
 in addition to any therapeutic benefits, TNFRs and
 TNFR/IgG fusion proteins were useful as diagnostic and
 research tools as well. Sandoz also points out that the spec-
 ification does not mention rheumatoid arthritis or contain
 any data regarding treatment efficacy. Appellants’ Br. 62.
 Sandoz argues that this contravenes the teachings of KSR
 Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007) that “neither
 the particular motivation nor the avowed purpose of the
 patentee controls. What matters is the objective reach of
 the claim.” Id. (citing KSR, 550 U.S. at 419).
      Immunex responds that it was Sandoz’s burden to
 prove motivation to combine, and at trial, Sandoz focused
 on these therapeutic goals as evidence of motivation to
 combine. Appellees’ Br. 71–72. Immunex points to
 Sandoz’s trial arguments that focused on the use of TNFR-
 IgG1 fusion proteins for treatment of autoimmune disor-
 ders. Id. According to Immunex, this focus on therapy
 made sense, because certain asserted claims cover pharma-
 ceutical compositions, not “research tools.” Id. at 73. Im-
 munex argues that the district court properly focused on
 the evidence presented and found that a POSA would not
 have been motivated to select the components of etaner-
 cept. Id. at 73–74. We agree with Immunex that the dis-
 trict court’s analysis was not legally erroneous.
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 28                             IMMUNEX CORP.   v. SANDOZ, INC.

     Although Sandoz and the amici criticize the district
 court’s focus on the therapeutic anti-inflammatory effect of
 TNFR binding proteins, that focus was a result of the ar-
 guments and evidence presented at trial and in the parties’
 post-trial submissions. For example, in its post-trial brief,
 Sandoz presented the dispute about motivation as limited
 to the following question: “Would a person of ordinary skill
 in the art in August 1990 have been motivated to construct
 a fusion protein of the p75 extracellular region fused to the
 hinge-CH2-CH3 of a human IgG1—i.e., etanercept?” J.A.
 60195. Sandoz’s own post-trial “findings of fact” focused on
 the fact that, at the time of the invention, several diseases
 were associated with overactive TNF, and that there was a
 tremendous interest in studying TNF activity and inhibi-
 tion to provide a therapeutic benefit. J.A. 60081–84 (“To a
 POSA [prior art] references provide a strong incentive to
 identify TNF inhibitors that may have therapeutic use.”).
 Likewise, Sandoz emphasized that a POSA would have
 considered fusing soluble receptors (like the p75 extracel-
 lular domain) advantageous for many reasons, including
 extending the half-life of the soluble receptor to prevent it
 from being rapidly lost from the patient’s blood stream into
 the urine. J.A. 60084–86. Finally, Sandoz focused on the
 primary asserted prior art reference (Immunex’s ’760 pa-
 tent) to argue that a POSA would have been motivated to
 modify the disclosures of that reference to create etaner-
 cept. J.A. 60086–97.
     In its post-trial submissions, Sandoz addressed the fact
 that the prior art “suggests using TNF-binding proteins as
 a tool in ‘diagnostic assays for TNF.’” See, e.g., J.A. 60083.
 It also noted that “the asserted claims are not directed to
 any specific treatment or in vivo effects and only require
 the fusion protein to, at most, specifically bind TNF . . .
 Such fusion protein would indisputably be useful for in
 vitro testing and diagnostics at a minimum.” J.A. 60123.
 And, Sandoz noted that the claims at issue do not require
 any therapeutic effect.       J.A. 60137–38.       But these
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 IMMUNEX CORP.   v. SANDOZ, INC.                           29

 arguments were presented in response to Immunex’s argu-
 ments that a POSA would be discouraged from creating a
 TNFR-human IgG1 fusion protein because of concerns of
 aggregation and effector functions. The focus of Sandoz’s
 motivation to combine argument remained the therapeutic
 benefits of the claimed invention, and it was not error for
 the district court to frame its analysis accordingly.
      We conclude that the district court’s analysis regarding
 motivation to combine was not legally erroneous because
 the treatment of illnesses that involve TNF is a stated ob-
 jective of the claimed invention; the arguments at trial
 were focused on therapeutic effects of the claimed inven-
 tion (and not on their benefits as diagnostic and research
 tools); and at least two of the asserted claims are directed
 to pharmaceutical compositions. On this record, the dis-
 trict court properly weighed the evidence presented and
 concluded as a matter of fact that a POSA would be dis-
 suaded from selecting or combining the components as
 claimed. We identify no clear error in this finding.
          2. Objective Indicia of Non-Obviousness
     Sandoz argues that the district court incorrectly ana-
 lyzed the required nexus between the claims and the objec-
 tive indicia of non-obviousness, such as clinical success,
 long-felt need, and failure of others. Appellants’ Br. 63–64.
 Sandoz further argues that the court did not properly con-
 sider evidence of simultaneous invention, as shown by ear-
 lier patents claiming etanercept, including Immunex’s
 Jacobs ’690 patent. Id. Sandoz’s arguments are without
 merit.
      As Immunex correctly argues, “there is a presumption
 of nexus for objective considerations when the patentee
 shows that the asserted objective evidence is tied to a spe-
 cific product and that product is the invention disclosed
 and claimed in the patent.” WBIP, LLC v. Kohler Co., 829
F.3d 1317, 1329 (Fed. Cir. 2016) (quotations omitted); Ap-
 pellees’ Br. 75–76. Nexus is appropriately presumed in this
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 30                             IMMUNEX CORP.   v. SANDOZ, INC.

 case where the court concluded that the claims are directed
 to the active ingredient in Enbrel® and its method of man-
 ufacture. The district court found that there was a suffi-
 cient nexus between the claimed invention and the various
 objective indicia of non-obviousness. Immunex, 395 F.
 Supp. 3d at 401–05. Sandoz failed to rebut the presump-
 tion of nexus.
     As to simultaneous invention, Immunex correctly notes
 that the district court found that three of the alleged in-
 stances of “simultaneous invention” were directed to differ-
 ent fusion proteins, not etanercept. Id. at 407; see also
 Appellees’ Br. 76. As to invention by Immunex, the court
 properly noted that the “patent applications were already
 pending when Immunex created etanercept in November
 or December 1990. Immunex’s subsequent decision to li-
 cense the Patents-in-Suit from Roche demonstrates etaner-
 cept’s inventive nature and undermines an obviousness
 finding.” Id. at 408. Finally, as we have discussed above,
 the district court correctly concluded that the Jacobs ’690
 patent does not cover etanercept, but is directed to fusion
 proteins with an unmodified constant region. It also issued
 from a continuation-in-part filed two years after the origi-
 nal applications for the patents-in-suit.        At bottom,
 Sandoz’s arguments regarding objective indicia are merely
 disagreements with the district court’s weighing of the ev-
 idence. We see no clear error in the district court’s findings
 regarding the objective indicia of non-obviousness.
                       III. CONCLUSION
      We have considered the parties’ remaining arguments
 and find them unpersuasive. For the foregoing reasons, we
 affirm the district court’s judgment that Sandoz has not
 shown that the patents-in-suit are invalid.
                         AFFIRMED
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    United States Court of Appeals
        for the Federal Circuit
                   ______________________

         IMMUNEX CORPORATION, AMGEN
           MANUFACTURING, LIMITED,
               Plaintiffs-Appellees

                HOFFMANN-LA ROCHE INC.,
                       Plaintiff

                             v.

  SANDOZ INC., SANDOZ INTERNATIONAL GMBH,
                SANDOZ GMBH,
               Defendants-Appellants
              ______________________

                         2020-1037
                   ______________________

     Appeal from the United States District Court for the
 District of New Jersey in No. 2:16-cv-01118-CCC-MF,
 Judge Claire C. Cecchi.
                  ______________________

 REYNA, Circuit Judge, dissenting.
      The majority determines that obviousness-type double-
 patenting does not apply here because appellee Immunex
 is not a common owner of the patents-in-suit. The major-
 ity’s common ownership determination hinges on its inter-
 pretation of the 2004 Accord & Satisfaction between
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 2                              IMMUNEX CORP.   v. SANDOZ, INC.

 Roche 1, the licensor of the patents-in-suit, and Immunex,
 the exclusive licensee. Because I interpret the 2004 Accord
 & Satisfaction as an effective assignment of the patents-in-
 suit to Immunex, I would hold that Immunex is a common
 owner for obviousness-type double patenting purposes. I
 would also hold that Immunex’s patents-in-suit are invalid
 for obviousness-type double patenting in view of Im-
 munex’s previously issued U.S. Patent No. 7,915,225 (“the
 ’225 patent”) under the one-way test. For this reason and
 the reasons discussed below, I respectfully dissent.
      I also provide additional views concerning the applica-
 bility of the one-way test for ODP purposes.
                    I. Common Ownership
      Obviousness-type double-patenting (“ODP”) is a judi-
 cially created doctrine designed to prevent a party from ex-
 tending its right to exclude through claims in a later-filed
 patent that are patentably indistinct from claims in a com-
 monly-owned earlier filed patent. In re Longi, 759 F.2d
887, 892 (Fed. Cir. 1985). A preliminary step for determin-
 ing whether the doctrine of ODP applies is whether the pa-
 tents at issue are commonly owned. See Eli Lilly & Co. v.
 Barr Labs., Inc., 251 F.3d 955, 968 (Fed. Cir. 2001); see also
 Longi, 759 F.2d at 895. The parties dispute whether ap-
 pellee Immunex is a common owner of the patents-in-suit
 such that the doctrine of ODP would be triggered.
     Here, the majority accepts appellant Sandoz’s novel
 theory that the “all substantial rights” test from the Sec-
 tion 281 context can be used to determine common owner-
 ship for ODP purposes. Maj. Op. at 11. Specifically, the
 majority explains that:

     1  Roche was a party in the district court litigation
 but has not entered its appearance in this appeal.
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 IMMUNEX CORP.   v. SANDOZ, INC.                              3

     [w]here, as here, [Immunex] ultimately controls
     prosecution of both sets of patents, the “all substan-
     tial rights” test aids in preventing the unjustifiable
     issuance of claims that are patentably indistinct
     from claims already owned by that party. Under
     these circumstances, looking to the “all substantial
     rights” test achieves the proper balance between
     deterring gamesmanship in prosecution, on the one
     hand, and avoiding any chilling effect on routine
     collaborations and licensing between parties work-
     ing in the same field of research, on the other.
Id. at 14–15 (emphasis added).
    While I commend the majority for adopting the “all sub-
 stantial rights” test, the majority’s adoption of that test
 was for naught. In applying the test, the majority permits
 the type of gamesmanship it sought to prevent—games-
 manship in prosecution which could result in unjustified
 extension of patent rights. Here, under the 2004 Accord &
 Satisfaction, Roche transferred to Immunex the sole right
 to control prosecution, an exclusive license, the absolute
 right to exclude Roche from commercializing the claimed
 inventions, the first right to sue, and the right to nullify
 any Roche-initiated suit by issuing a royalty-free license.
 Specifically, Immunex’s sole right to control prosecution is
 significant in the ODP context, since the doctrine of ODP
 is meant to prevent applicants from receiving patents that
 extend the life of their existing patents. See In re Hubbell,
 709 F.3d 1140, 1145 (Fed. Cir. 2013). The facts here reveal
 why.
     When under Roche’s control for almost ten years, the
 applications from which the patents-in-suit issued did not
 claim the etanercept fusion protein, but rather a different
 fusion protein and a mutated version of etanercept. How-
 ever, once Immunex retained control of prosecution, Im-
 munex amended the applications to claim etanercept,
 which Immunex itself had claimed in its own patents and
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 4                              IMMUNEX CORP.   v. SANDOZ, INC.

 which was an active ingredient in Immunex’s Enbrel®
 product. Thus, thanks to its prosecution efforts, Immunex
 has effectively extended to 2029 its right to exclude public
 use of the etanercept fusion protein via the patents-in-suit
 (which Immunex effectively owns in all material respects).
 Given this backdrop, I would hold that Immunex effectively
 owns the patents-in-suit for ODP purposes.
    The majority, however, reasons that Roche remains the
 true owner for ODP purposes because under the 2004 Ac-
 cord & Satisfaction, Roche retained a secondary right to
 sue and a right to veto an Immunex-initiated assignment.
 See Maj. Op. at 18–20. However, as explained below,
 Roche’s retained rights are illusory, and, thus, do not inter-
 fere with Immunex’s control to practice and enforce the pa-
 tents-in-suit.
     “[L]abels given by the parties do not control” the all-sub-
 stantial-rights inquiry. A123 Sys., Inc. v. Hyrdo-Quebec,
 626 F.3d 1213, 1218 (Fed. Cir. 2010). Rather, the court
 looks to the “substance” of the written agreement “rather
 than formalities or magic words.” Lone Star Silicon Inno-
 vations LLC v. Nanya Tech. Corp., 925 F.3d 1225, 1229
 (Fed. Cir. 2019). Specifically, if the licensor’s only remain-
 ing rights in the patents-in-suit are “illusory,” then the li-
 censor has effectively transferred all substantial rights to
 the licensee. See Speedplay, Inc. v. Bebop, Inc., 211 F.3d
1245, 1251 (Fed. Cir. 2000). A licensor’s right is illusory if
 it “would not hinder [the licensee’s] enjoyment of the patent
 rights in any meaningful way.” Id. In other words, the li-
 censor’s right is illusory for ownership purposes if it does
 not meaningfully interfere with the licensee’s control and
 enforcement of the patents at issue. See id.
    Here, Roche’s two retained rights, i.e., a secondary right
 to sue and a right to veto an Immunex-initiated assign-
 ment, are illusory because these rights do not prevent Im-
 munex from enjoying the patents-in-suit in any meaningful
 way. Id. Specifically, pursuant to the 2004 Accord &
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 IMMUNEX CORP.   v. SANDOZ, INC.                            5

 Satisfaction, Immunex can at any time nullify Roche’s
 rights by ordering Roche to assign the patents-in-suit to
 Immunex upon payment of $50,000. J.A. 25840. Once Im-
 munex forces Roche’s hand, Roche has no choice but to as-
 sign the patents-in-suit to Immunex, leaving Roche with no
 rights at all. Id. (“If requested . . . Roche shall execute
 an assignment of [the patents].” (emphasis added)). Roche
 cannot terminate this arrangement for any reason.
 J.A. 25848 (“Roche will have no right to terminate this [Ac-
 cord & Satisfaction] for any reason.”). Thus, if Immunex
 disagrees with Roche’s decision to initiate suit or Roche’s
 decision to veto an assignment, Immunex can undo Roche’s
 decisions by simply obtaining official ownership of the pa-
 tents-in-suit.
     Additionally, the record shows that Immunex’s pay-
 ment of $50,000 to Roche does not meaningfully hinder Im-
 munex’s enjoyment of the patents-in-suit but rather is a
 self-executing formality. First, the evidence shows Roche
 did not value its retained rights. During negotiations for
 Immunex’s “license,” Roche was willing to formally assign
 the patents-in-suit at no additional cost. Specifically,
 Roche’s former Senior Counsel, who drafted and negotiated
 the Roche-Immunex 2004 Accord & Satisfaction on behalf
 of Roche, testified that “Roche wouldn’t have had a problem
 if [Immunex] had asked for an assignment [and] not to
 charge them the $50,000 from day one.” J.A. 28335. Yet,
 Roche included the $50,000 clause at the insistence of Im-
 munex. Second, that Immunex would have to pay Roche
 $50,000 is not a meaningful hinderance to Immunex’s en-
 joyment of the patents-in-suit. Speedplay, 211 F.3d at
 1251. The record shows that $50,000 is a de minimis
 amount for Immunex. Consider that Immunex paid ap-
 proximately $45 million for its alleged “license.” Addition-
 ally, etanercept, the fusion protein claimed by the patents-
 in-suit, earned $1.9 billion in revenue in 2004, the year Im-
 munex received its “license.” Thus, it is unreasonable to
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 6                              IMMUNEX CORP.   v. SANDOZ, INC.

 conclude that $50,000 represents a meaningful hinderance
 to Immunex’s effective ownership over the patents-in-suit.
     Roche’s secondary right to sue is rendered illusory for
 an additional, separate reason. Pursuant to the 2004 Ac-
 cord & Satisfaction, Roche’s “right” to commence a civil ac-
 tion for infringement is subject to Immunex’s approval.
 Specifically, under Section 3.6 of the 2004 Accord & Satis-
 faction, Roche must notify Immunex of any infringement in
 a written request. Under Sections 3.1 and 3.5, Immunex
 may nullify Roche’s right to sue by issuing a royalty-free
 sublicense to the alleged infringer. The sleight of hand
 here is that Immunex retains full control over whether
 Roche can initiate suit. To stop Roche from pursuing an
 infringement action, Immunex need only issue a royalty-
 free sublicense. See Speedplay, 211 F.3d at 1251 (noting
 that the licensor’s secondary right to sue was “illusory” be-
 cause the licensee “can render [it] nugatory by granting the
 alleged infringer a royalty-free sublicense”). Thus, “[e]ven
 though [Roche] retained the right to sue, that right would
 not hinder [Immunex’s] enjoyment of the patent rights in
 any meaningful way.” Id.
     The majority reasons that Immunex’s sublicensing
 right does not render Roche’s secondary right to sue illu-
 sory. See Maj. Op. at 19–20. The majority’s sole reason for
 concluding as much is that this case is different from
 Speedplay. The majority notes that Speedplay “held that a
 licensee’s right to grant royalty-free sublicenses to defend-
 ants sued by the licensor rendered illusory the licensor’s
 right to sue.” Id. (quoting Alfred E. Mann Found. for Sci.
 Research v. Cochlear Corp., 604 F.3d 1354, 1362 (Fed. Cir.
 2010)) (emphasis in majority opinion). 2 The majority

     2   The majority asserts that the dissent “fails to ac-
 count” for the decision in Alfred E. Mann, “where we ex-
 plained that the holding in Speedplay turned on the
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 IMMUNEX CORP.   v. SANDOZ, INC.                               7

 reasons that Speedplay does not apply because Immunex
 cannot issue a sublicense once Roche initiates suit, unlike
 the Speedplay licensee. Id.
     That the Speedplay licensee could issue a sublicense
 post-suit does not render Roche’s secondary right to sue
 any less illusory. The focus of the Speedplay inquiry is
 whether a licensee can nullify a licensor’s secondary right
 to sue, pre- or post-suit. See Speedplay, 211 F.3d at 1251
 (making no distinction as to the timing of issuance of a roy-
 alty-free sublicense); see also Lone Star, 925 F.3d at 1231;
 AsymmetRx, Inc. v. Biocare Med., LLC, 582 F.3d 1314, 1320
 (Fed. Cir. 2009); Intellectual Prop. Dev., Inc. v. TCI Cablevi-
 sion of Cal., Inc., 248 F.3d 1333, 1343 (Fed. Cir. 2001).
 Here, Immunex can issue a royalty-free sublicense within
 180 days of receiving Roche’s written request to correct in-
 fringement and can thus prevent Roche’s secondary right
 to sue from even vesting. If Roche ultimately sues, it is
 only because Immunex allowed Roche to do so. As in

 licensee’s ability to frustrate a licensor-initiated suit.” Maj.
 Op. at 20. I respectfully disagree. The majority reads Al-
 fred E. Mann too narrowly. In Alfred E. Mann, we
 acknowledged the Speedplay licensee’s “ability to settle li-
 censor-initiated litigation by granting royalty-free subli-
 censes to the accused infringers.” Alfred E. Mann, 604 F.3d
 at 1361. However, like in Speedplay, we did not hold that
 a secondary right to sue is rendered illusory only when a
 licensee can issue a royalty-free sublicense post-suit. Ra-
 ther, we explained that the illusory inquiry should be flex-
 ible, looking broadly to the “nature and scope of the
 licensor’s retained right to sue.” Id. Contrary to the ma-
 jority opinion, the key inquiry here should be whether a li-
 censee can issue a royalty-free sublicense, regardless of
 whether the sublicense issued pre- or post-suit. For once
 the licensee issues this unfettered sublicense, the licensee
 nullifies the licensor’s secondary right to sue.
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 8                               IMMUNEX CORP.   v. SANDOZ, INC.

 Speedplay, Roche’s secondary right to sue is subject to neu-
 tralization and thus illusory. Speedplay, 211 F.3d at 1251.
     In sum, because Roche’s two retained rights in the pa-
 tents-in-suit are illusory, I would hold that Immunex
 owned the patents-in-suit for ODP purposes.
                     II. Additional Views
      Although the majority does not reach this issue, I
 briefly address the second prong to the ODP inquiry—
 whether the patents-in-suit are patentably indistinct from
 Immunex’s previously issued ’225 patent. Here, the dis-
 trict court alternatively determined that the doctrine of
 ODP does not apply because the patents-in-suit were pa-
 tentably distinct from Immunex’s previously issued ’225
 patent under the “two-way” test. I would hold that the dis-
 trict court legally erred in applying the “two-way” test ra-
 ther than the “one-way” test.
      The “two-way” test is a “narrow exception to the gen-
 eral rule of the one-way test,” and it is only appropriate
 “where (1) a second-filed application issues prior to a first-
 filed application, and (2) the PTO is solely responsible for
 the delay in the issuance of the first-filed application.” In
 re Janssen Biotech, Inc., 880 F.3d 1315, 1325 (Fed. Cir.
 2018) (internal quotation marks omitted) (emphasis
 added); see also In re Basell Poliolefine Italia S.P.A., 547
F.3d 1371, 1376 (Fed. Cir. 2008) (noting that the two-way
 test is appropriate in “the unusual circumstance that the
 PTO is solely responsible for the delay” (emphasis added)).
 Whether the one-way test or two-way test applies is a ques-
 tion of law. See In re Emert, 124 F.3d 1458, 1460 (Fed. Cir.
 1997).
     Here, the district court noted that both the PTO and
 Roche/Immunex contributed to the delay in prosecution of
 the patents-in-suit yet concluded that the PTO was “solely
 responsible” for the delay. This was legal error. Our case
 law is clear that if the applicant’s “actions, or inactions, had
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 IMMUNEX CORP.   v. SANDOZ, INC.                            9

 a direct effect on the prosecution,” the PTO is not “solely”
 responsible for the delay, and, thus, the “two-way test . . .
 does not apply.” In re Basell, 547 F.3d at 1376; see also In
 re Fallaux, 564 F.3d 1313, 1316 (Fed. Cir. 2009); Eli Lilly,
251 F.3d at 968 n.7; In re Emert, 124 F.3d at 1461. Thus,
 both Roche’s and Immunex’s contribution to the delay in
 prosecution—mainly, their requests for extensions and
 Roche’s delay in filing the etanercept claims during prose-
 cution of the patents-in-suit—should have, as a matter of
 law, triggered the application of the one-way test. See In
 re Basell, 547 F.3d at 1376; see also Eli Lilly, 251 F.3d at
 968 n.7.
     There is no serious dispute that under the one-way
 test—which asks whether the asserted patent claim is ob-
 vious over or anticipated by the earlier-issued patent claim,
 see In re Hubbell, 709 F.3d at 1149—Immunex’s patents-
 in-suit are patentably indistinct from Immunex’s ’225 pa-
 tent. Thus, Immunex’s patents-in-suit are invalid for ODP
 in view of Immunex’s ’225 patent.
    I respectfully dissent.