Full opinion text
SCHALL, Circuit Judge. This is a patent case. Amgen Inc. (“Amgen”) is the owner of U.S. Patent Nos. 5,441,868 (“the '868 patent”), 5,547,-933 (“the '933 patent”), 5,618,698 (“the '698 patent”), 5,756,349 (“the '349 patent”), and 5,955,422 (“the '422 patent”). The patents relate to the production of the protein erythropoietin (“EPO”) using recombinant deoxyribonucleic acid (“DNA”) technology. All five patents share a common specification and descend from Application No. 06/675,298 (“the '298 application”), which issued as now-expired U.S. Patent No. 4,703,008 (“the '008 patent”). In November of 2005, Amgen brought a declaratory judgment action against F. Hoffman-La Roche Ltd, Roche Diagnostics GMBH, and Hoffman-La Roche Inc. (“Roche”) in the United States District Court for the District of Massachusetts, alleging that Roche’s product, MIRCERA®, would infringe Amgen’s five patents if imported into the United States. Roche responded with affirmative defenses and counterclaims that Amgen’s asserted patents were invalid and not infringed. In October of 2008, following rulings of summary judgment and judgment as a matter of law (“JMOL”), and a jury trial, the court entered judgment that the '868, '933, '698, and '422 patents were infringed and not invalid, and that the '349 patent was neither invalid nor infringed. Amgen, Inc. v. F. Hoffman-La Roche Ltd., No. 05-12237-WGY, slip op. at 1-2 (D.Mass. Oct. 17, 2008) (“Final Judgment ”). Accordingly, the court granted Amgen declaratory relief and permanently enjoined Roche from marketing MIRCERA® in the United States. Id. Roche appeals from several rulings of the court. Specifically, Roche challenges the court’s rulings that none of the claims-in-suit were invalid for obviousness-type double patenting, Amgen, Inc. v. F. Hoffman-La Roche Ltd., 581 F.Supp.2d 160, 173, 186, 192 (D.Mass.2008); and that claim 1 of the '422 patent was neither anticipated nor indefinite and infringed, id. at 194, 198, 204. Roche also challenges the court’s rulings sustaining the jury’s verdict that claims 3, 7, and 8 of the '933 patent were neither anticipated nor indefinite; and that claims 3, 7, and 8 of the '933 patent, claims 1 and 2 of the '868 patent, and claims 6-9 of the '698 patent were literally infringed. Amgen cross-appeals from the court’s rulings that claim 7 of the '349 patent and claims 9,11, and 14 of the '933 patent were not infringed. Amgen also cross-appeals from the court’s ruling vacating the jury’s verdict that claim 12 of the '933 patent was infringed under the doctrine of equivalents (“DOE”). Id. at 205. We vacate the court’s grant of summary judgment and of JMOL to Amgen of no invalidity for obviousness-type double patenting of claims 3, 7, and 8 of the '933 patent; claim 1 of the '422 patent; and claim 7 of the '349 patent. We therefore remand to the district court for an obviousness-type double patenting analysis of those claims in light of this opinion. We also vacate the court’s grant of JMOL to Roche of non-infringement of claim 7 of the '349 patent and remand to the district for a new trial on infringement of that claim. We affirm the court’s judgment in all other respects. BACKGROUND I As noted, the patents at issue relate to the production of EPO using recombinant DNA technology. EPO, which is a naturally occurring protein (or polypeptide), stimulates the production of red blood cells through a process called erythropoiesis. Amgen, 581 F.Supp.2d at 168. The production of EPO is useful in treating blood disorders characterized by a low hematocrit, which is a low ratio of red blood cells to total blood cells. Id. One such blood disorder is anemia. In a clinical study performed in 1979-80, Dr. Eugene Goldwasser attempted to treat anemic patients with EPO isolated from human urine. Id. at 168. He had limited success, however, because the EPO recovered from urine was low-yield, of high impurity, and unstable. Id. at 168-69. Rather than attempting to obtain EPO from natural sources such as human urine, a team of Amgen researchers led by Dr. Fu-Kuen Lin identified a means of producing usable amounts of EPO via recombinant DNA technology. Id. at 169. The common specification of Amgen’s patents describes the production of recombinant EPO. To produce EPO, Dr. Lin made an expression vector carrying the human EPO DNA sequence he had discovered. See '422 patent col. 11 11.1-10. An expression vector is a circular piece of DNA that is inserted into a host cell to produce a protein. Id. col.2 11.36-54; figs.2 & 3. He then injected, or transfected, host Chinese hamster ovary (“CHO”) cells with the expression vector. Id. col. 1111.5-10 The transfected CHO cells use the EPO DNA sequence to form a protein with the 166 amino acid sequence of EPO shown in Figure 6 of the common specification of the patents. Id. fig.6. Prior to secretion of EPO from the cell, the final amino acid, or the C-terminal amino acid, of the 166 amino acid sequence is cleaved off, leaving a 165 amino acid protein. Amgen, 581 F.Supp.2d at 170. Also prior to secretion, carbohydrates are attached to certain sites on EPO in a process called glycosylation, which results in a glycoprotein. Id. Thus, Dr. Lin’s transfected CHO cells ultimately yield a glycoprotein with the 165 amino acid sequence of human EPO. Id. Recombinant EPO produced in this manner can bind to the EPO receptor and stimulate erythropoiesis. Id. at 169. On November 30, 1984, Amgen submitted to the United States Patent and Trademark Office (“PTO”) the '298 application, from which Amgen’s five patents descend. Id. at 180. The '298 application originally contained claims drawn to, inter alia, DNA sequences, host cells, processes of producing polypeptides, polypeptides, and pharmaceutical compositions. Id. In 1986, the PTO subjected Amgen’s '298 application to a restriction requirement, which identified claims drawn to DNA, cells, polypeptides, and pharmaceutical compositions as each directed to patentably distinct subject matter. Id. The PTO examiner stated that, under 35 U.S.C. § 121, restriction to one of the following inventions was required: I. Claims 1-13, 16, 39-41, 47-54, and 59, drawn to polypeptide, classified in Class 260, subclass 112. II. Claims 14, 15, 17-36, 58, and 61-72, drawn to DNA, classified in Class 536, subclass 27. III. Claims 37-38, drawn to plasmid, classified in Class 435, subclass 317. IV. Claims 42-46, drawn to cells, classified in Class 435, subclass 240. V. Claims 55-57, drawn to pharmaceutical composition, classified in Class 435, subclass 177. VI. Claim 60, drawn to assay, classified in Class 435, subclass 6. Id. In response, Amgen elected to prosecute Group II claims in the '298 applieation, which were drawn to DNA and host cells. Id. Ultimately, the '298 application issued on October 27, 1987, as the now-expired '008 patent entitled “DNA Sequences Encoding Erythropoietin.” The '008 patent claimed DNA sequences encoding EPO and host cells transformed or transfected with those DNA sequences. '008 patent col.40 11.17-68. On October 23, 1987, subsequent to the restriction requirement but before the '008 patent issued, Amgen prosecuted the claims withdrawn from the '298 application in continuation application 07/113,178 (“the '178 application”) and continuation application 07/113,179 (“the '179 application”). Amgen, 581 F.Supp.2d at 180. After a series of intervening continuation applications and interferences, the '933 patent eventually emerged from the '178 application, while the '422, '349, '868, and '698 patents eventually emerged from the '179 application. As a result, all five patents-in-suit (’933, '422, '349, '868, and '698) claim priority to the '298 application, share a common specification, and have the title “Production of Erythropoietin” or “Production of Recombinant Erythropoietin.” In broad strokes, the '933 patent claims recombinant EPO, a pharmaceutical composition comprising recombinant EPO, and methods of treating kidney dialysis patients by administering pharmaceutical compositions comprising recombinant EPO. '933 patent col.38 1.17-eol.40 1.11. The '422 patent claims a pharmaceutical composition comprising recombinant EPO. '422 patent col.38 1.37-41. Because the '933 and '422 patents both cover recombinant EPO and pharmaceutical compositions thereof, the parties refer to them collectively as the “product patents.” The '349 patent claims the process of producing recombinant EPO in vertebrate cells capable of producing EPO at a specific rate. '349 patent col.38 11.34-36. The '868 patent claims the process of producing recombinant EPO in mammalian cells, '868 patent col.38 11.24-37, while the '698 patent claims the process of producing recombinant EPO in cells comprised of amplified DNA encoding EPO, '698 patent col.38 11.50-65. Because the '868 and '698 patents both cover processes of producing recombinant EPO, the parties refer to them collectively as the “process patents.” Based on these patents, Amgen has developed two erythropoiesis-stimulating agent (“ESA”) drugs, EPOGEN® and Aranesp®, to treat anemia and anemia-related diseases. Amgen, 581 F.Supp.2d at 171. The key difference between these drugs is how frequently patients must take them. Id. The Food and Drug Administration (“FDA”) has approved EPOGEN for weekly dosing and Aranesp for biweekly dosing to anemic patients. Id. Roche sought to introduce into the United States market its own ESA drug, MIRCERA®, which it manufactures overseas. Id. at 172. The active ingredient of MIRCERA® is continuous erythropoietin receptor activator (“CERA”). CERA is formed via a chemical reaction that bonds polyethylene glycol (“PEG”) to recombinant EPO produced by CHO cells. Id. The attachment of one PEG molecule to EPO, also known as pegylation of EPO, results in the displacement of a single hydrogen atom from the amino acid lysine or from the beginning amino acid (i.e., the N-terminus) of EPO. Id. Pegylation of a therapeutic protein, such as EPO, can expand the drug’s life in the body and reduce levels of toxicity, allowing for extended dosing intervals. Id. As a result, MIRCERA® has received FDA approval for once-monthly dosing to anemic patients. Id. II Amgen sought a declaratory judgment that, if imported into the United States, MIRCERA® would infringe the '933, '422, '868, '698, and '349 patents. Specifically, Amgen alleged infringement of claims 3, 7-9, 11, 12, and 14 of the '933 patent, claim 1 of the '422 patent, claim 7 of the '349 patent, claims 1-2 of the '868 patent, and claims 6-9 of the '698 patent. Roche responded with affirmative defenses and counterclaims that Amgen’s asserted patents were invalid and not infringed. After discovery, the district court granted Amgen summary judgment of no obviousness-type double patenting of any of the asserted claims in the '933, '422, and '349 patents over the claims in the '008 patent based on the protection from such challenge afforded by 35 U.S.C. § 121. Amgen, 581 F.Supp.2d at 173. Over cross-motions for summary judgment, the district court also granted Amgen summary judgment that claim 1 of the '422 patent was infringed. Id. at 167, 204. The parties tried the remaining infringement and invalidity claims to a jury. After Roche presented its case-in-chief to the jury, the court granted Amgen JMOL that claim 1 of the '422 patent was not anticipated. Id. at 198. After conducting hearings outside the presence of the jury and reviewing the trial record, the court granted Amgen JMOL of no obviousness-type double patenting of (1) the asserted claims in the '933, '422, and '349 patents over the claims in the '868 and '698 patents, id. at 192, and (2) the asserted claims in the '868 and '698 patents over the claims in the '008 patent, id. at 186. The court also granted Roche JMOL that claims 9, 11, and 14 of the '933 patent and claim 7 of the '349 patent were not infringed. On October 23, 2007, the jury rendered a verdict in favor of Amgen, upholding the validity of all the claims-in-suit. The jury found that Roche literally infringed claims 3, 7, and 8 of the '933 patent; claims 1 and 2 of the '868 patent; and claims 6-9 of the '698 patent. Over Roche’s motions for renewed JMOL and a new trial, the court sustained these jury findings. The jury also found that claim 12 of the '933 patent was infringed under the DOE. Granting Roche’s motion for renewed JMOL relating to claim 12 of the '933 patent, the court vacated the jury verdict of infringement and entered judgment of non-infringement as to that claim. Id. at 205. Subsequently, the court granted Amgen a declaratory judgment and a permanent injunction, enjoining Roche from marketing MIRCERA® in the United States. Final Judgment, slip op. at 1-2. Roche appeals the described rulings and findings in favor of Amgen, while Amgen cross-appeals the described rulings in favor of Roche. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). DISCUSSION In this appeal, we are presented with issues involving obviousness-type double patenting, anticipation, indefiniteness, and infringement relating to the '933, '422, '349, '868, and '698 patents. I Obviousness-Type Double Patenting For purposes of explaining its rulings relating to obviousness-type double patenting, the district court grouped the '933, '422, and '349 patents, and the '868 and '698 patents separately. We shall do the same. A The court granted Amgen summary judgment of no obviousness-type double patenting of the asserted claims of the '933, '422, and '349 patents over the claims of the '008 patent. Amgen, 581 F.Supp.2d at 179. The court also granted Amgen JMOL of no obviousness-type double patenting of the asserted claims of the '933, '422, and '349 patents over the claims of the '868 and '698 patents. Id. at 192. The court arrived at these rulings after concluding that the '933, '422, and '349 patents were shielded from double patenting by 35 U.S.C. § 121. Id. Section 121, entitled “Divisional applications,” provides in its third sentence: A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application. 35 U.S.C. § 121. The third sentence of § 121 is a safe harbor provision that protects a divisional application, the original application, or any patent issued on either of them from validity challenges based on a patent issuing on an application subjected to a restriction requirement or on an application filed as a result of a restriction requirement. In effect, the third sentence of § 121 shields patents that issue on applications filed as a result of a restriction requirement from double patenting invalidation. See Applied Materials, Inc. v. Advanced Semiconductor Materials America, Inc., 98 F.3d 1563, 1568 (Fed.Cir.1996) (“[Wjhen two or more patents result from a PTO restriction requirement, whereby aspects of the original application must be divided into separate applications, § 121 insulates the ensuing patents from the charge of double patenting.”). The court concluded that the '933, '422, and '349 patents were entitled to the § 121 safe harbor because they had descended from the '178 and '179 applications, both of which had been filed in response to a PTO-imposed restriction requirement. The court observed that “[ajfter the PTO imposed the 1986 restriction requirement,” Amgen “filed two divisional applications, the '178 and '179, which ultimately issued as the '933, '422, and '349 patents.” Am-gen, 581 F.Supp.2d at 179. The court found that the “undisputed evidence show[ed] that both the '178 and '179 applications were filed as a result of the PTO’s 1986 restriction requirement.” Id. Thus, the court deemed the '933, '422, and '349 patents immune from a charge of obviousness-type double patenting over the '008, '868, and '698 patents. Id. at 182, 192. On appeal, Roche contends that the district court erroneously determined that § 121’s safe harbor insulates the '933 and '422 patents from obviousness-type double patenting invalidation over the '008, '868, and '698 patents. Roche’s Br. 34. Roche’s main contention is that § 121 cannot shield the '933 and '422 patents because they issued from solely continuation applications to which § 121 is inapplicable. Id. Roche contends that § 121 applies exclusively to divisional applications and patents issuing therefrom. Roche emphasizes that the statute, entitled “Divisional applications,” requires on its face that the later patent must issue from “a divisional application” or the “original application.” Id. at 35. Because the '933 and '422 patents issued from the '178 and '179 continuation applications, Roche contends they are not entitled to the § 121 safe harbor. Id. at 36. Amgen argues that the district court correctly held that § 121 protects the asserted claims of the '933 and '422 patents from obviousness-type double patenting invalidation over the claims of the '008, '868, and '698 patents. Amgen’s Br. 39. Am-gen relies on our decisions in Applied Materials, Inc. v. Advanced Semiconductor Materials Am., Inc., 98 F.3d 1563, 1568 (Fed.Cir.1996), and Symbol Technologies, Inc. v. Opticon, Inc., 935 F.2d 1569 (Fed. Cir.1991), for the proposition that patents that issue directly from continuation applications, as the '933 and '422 patents did, are eligible for § 121 protection so long as the other requirements of § 121 are met. Id. at 41. In Amgen’s view, the only § 121 requirement at issue is the “divisional application” requirement, and Amgen contends that the '178 and '179 applications meet that requirement. Id. Amgen urges the court to look to an application’s substance — not its designation — to determine whether it qualifies as a divisional application under § 121’s safe harbor. Id. at 42. In support of this approach, Amgen relies on the definition of “divisional application” in § 201.06 of the Manual of Patent Examining Procedure (“MPEP”), which provides: A later application for an independent or distinct invention, carved out of a pending application and disclosing and claiming only subject matter disclosed in the earlier or parent application, is known as a divisional application or “division.” MPEP § 201.06 (8th ed., July 2008 rev.). According to Amgen, the '178 and '179 applications were later applications, which were (1) carved out of a pending application (the '298 application), (2) contained claims to distinct and independent inventions, and (3) disclosed and claimed only subject matter disclosed in the earlier or parent application. Amgen’s Br. 41. Thus, Amgen argues, because the '178 and '179 applications, from which the '933 and '422 patents descend, conform to the PTO’s definition of a “divisional application” in MPEP § 201.06, the '933 and '422 patents are entitled to the § 121 safe harbor. Id. Amgen also noted at oral argument that Roche did not contest the no obviousness-type double patenting ruling relating to the '349 patent in its reply brief, even though Amgen cross-appealed the court’s ruling that the '349 patent was not infringed by MIRCERA®. See Oral Arg. 33:10-35, June 4, 2009, available at http:// oralarguments.cafc.uscourts.gov/ searchscript.asp (search case no.2009-1020). Amgen urges us to treat Roche’s omission as waiver. Id. We address this last point of Amgen’s first. Amgen correctly points out that Roche did not challenge the § 121 protection afforded to the '349 patent in its reply brief. When questioned at oral argument about this omission, counsel for Roche stated, “We won on non-infringement, so you can’t appeal when you win.” Oral Arg. 37:00-27. While a challenge to the no invalidity ruling of the '349 patent would have been a proper response to Amgen’s cross-appeal of the non-infringement ruling of the '349 patent, we do not deem Roche’s failure to raise this alternative ground for affirmance as waiver in this case. See Independence Park Apartments v. United States, 449 F.3d 1235, 1240 (Fed. Cir.2006) (explaining that appellees are in the position of defending a favorable judgment and, under certain circumstances, may not be “required to raise all possible alternative grounds for affirmance to avoid waiving any of those grounds”); cf. Harris Corp. v. Ericsson Inc., 417 F.3d 1241, 1251 (Fed.Cir.2005) (“An appellate court retains case-by-case discretion over whether to apply waiver.”). Therefore, given our ruling on infringement of the '349 patent, see infra Part Y.B, we will rule on whether the '349 patent is entitled to the § 121 safe harbor. B We review a district court’s grant of summary judgment without deference. See In re Metoprolol Succinate Patent Litig., 494 F.3d 1011, 1015 (Fed.Cir.2007). Summary judgment is appropriate if there are no genuine issues of material fact so that the moving party is entitled to judgment as a matter of law. See Fed.R.Civ.P. 56(c). In other words, the court properly grants summary judgment if no reasonable jury could return a verdict for the non-moving party. See Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986). In assessing the evidence, we draw all reasonable inferences in favor of the non-moving party. BMC Res., Inc. v. Paymentech, L.P., 498 F.3d 1373, 1378 (Fed.Cir.2007). We apply the standard of review for JMOL rulings used in the relevant regional circuit. DePuy Spine, Inc. v. Medtronic Sofamor Danek, Inc., 567 F.3d 1314, 1329 (Fed.Cir.2009). In this case, that is the First Circuit. In the First Circuit, a district court’s grant of JMOL is reviewed without deference. Id. (applying First Circuit law). Under First Circuit law, JMOL is warranted when, viewing the evidence in the light most favorable to the non-moving party, “there is no legally sufficient evidentiary basis for a reasonable jury to find for the [non-moving] party.” Guilloty Perez v. Pierluisi, 339 F.3d 43, 50 (1st Cir.2003) (quotation marks omitted). We review a court’s conclusion on double patenting without, deference because “double patenting is a matter of what is claimed, and therefore is treated like claim construction upon appellate review.” Georgia-Pacific Corp. v. U.S. Gypsum Co., 195 F.3d 1322, 1326 (Fed.Cir. 1999). “[Obviousness-type] double patenting is a judicially created doctrine adopted to prevent claims in separate applications or patents that do not recite the ‘same’ invention, but nonetheless claim inventions so alike that granting both exclusive rights would effectively extend the life of patent protection.” Perricone v. Medicis Pharm. Corp., 432 F.3d 1368, 1373 (Fed.Cir.2005). We conclude that, because the '178 and '179 applications were filed as continuation — rather than divisional — applications, the '933, '422, and '349 patents do not receive the benefit of § 121. We reach this conclusion in light of our opinion in Pfizer, Inc. v. Teva Pharmaceuticals USA Inc., 518 F.3d 1353 (Fed.Cir.2008). The Pfizer decision addressed whether a patent that issued from a continuation-in-part application — rather than a divisional application — could receive the protection of the § 121 safe harbor. 518 F.3d at 1358-62. Looking first to the statute, the court observed that § 121 on its face refers to “divisional applieation[s].” Id. at 1360. Turning to the legislative history, the court observed that a House Report also referred specifically to “divisional application^].” Id. Notably absent from the legislative history, in the court’s view, was a suggestion “that the safe-harbor provision was, or needed to be, directed at anything but divisional applications.” Id. at 1361. From there, the court “eonclude[d] 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.” Id. at 1362. Accordingly, the court decided that the § 121 safe harbor did not apply to the patent before it, which issued from a continuation-in-part application. Id. We are persuaded by the reasoning in Pfizer that the § 121 safe harbor provision does not protect continuation applications or patents descending from only continuation applications. The statute on its face applies only to divisional applications, and a continuation application, like a continuation-in-part application, is not a divisional application. See Gerber Garment Tech., Inc. v. Lectra Sys., Inc., 916 F.2d 683, 688 (Fed.Cir.1990) (“To gain the benefits of Section 121 there outlined, [the patentee] must have brought its case within the purview of the statute, i.e., it must have limited the claims in its divisional application to the non-elected invention or inventions.” (emphasis added)). We recognize that, unlike a continuation-in-part application, a continuation application can satisfy the definition of a “divisional application” in MPEP § 201.06. That is because a continuation-in-part application adds subject matter not disclosed in the earlier application, see MPEP § 201.08, whereas continuation and divisional applications are limited to subject matter disclosed in the earlier application, see MPEP §§ 201.06, 201.07. This distinction, however, does not justify departing from a strict application of the plain language of § 121, which affords its benefits to “divisional application[s].” See 35 U.S.C. § 121 (sheltering from attack “a divisional application or ... the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application” (emphases added)); see also Geneva Pharm., Inc. v. GlaxoSmithKline PLC, 349 F.3d 1373, 1382 (Fed.Cir.2003) (“Given the potential windfall [a] patent term extension could provide to a patentee, this court applies a strict test for application of § 121.” (footnote omitted)). Our conclusion that the § 121 safe harbor protects patents descending from divisional applications, but not from continuation applications exclusively, is consistent with our decisions in Applied Materials and in Symbol Technologies. In both of those cases, we affirmed § 121 protection of patents which issued directly from continuation applications. See Applied Materials, 98 F.3d at 1568-69; Symbol Technologies, 935 F.2d at 1579-81. In both cases, however, the continuation applications, from which the protected patents issued, descended from divisional applications that were filed as a result of restriction requirements. See Applied Materials, 98 F.3d at 1568; Symbol Technologies, 935 F.2d at 1580. Our decisions in Applied Materials and Symbol Technologies thus establish that a patent need not have issued directly from a divisional application to receive § 121 protection. In other words, intervening continuation applications do not render a patent ineligible for § 121 protection so long as they descended from a divisional application filed as a result of a restriction requirement. Unlike the patents at issue in Applied Materials and Symbol Technologies, the '933, '422, and '349 patents issued from continuation applications, which descended from continuation applications exclusively, and not from divisional applications. Thus, Applied Materials and Symbol Technologies are of no help to Amgen’s position that the '933, '422, and '349 patents deserve § 121 protection. Furthermore, Amgen has not presented us with any persuasive reason as to why we should deem the '178 and '179 continuation applications divisional applications for purposes of § 121. Amgen does not dispute that it denominated the '178 and '179 applications continuations, that it checked the continuation application box on the submitted form, or that its applications met the PTO’s definition of a continuation application in MPEP § 201.07. See Amgen’s Br. 38, 42. Instead, Amgen argues that, because the '178 and '179 continuation applications could have been filed as divisional applications, we should treat them as such for purposes of § 121. While this argument convinced the district court to regard the '178 and '179 continuation applications as divisional applications, we are not likewise convinced. We decline to construe “divisional application” in § 121 to encompass Amgen’s properly filed, properly designated continuation applications. Because the '178 and '179 applications were filed as continuation applications instead of divisional applications, we hold that the '933, '422, and '349 patents do not receive the protections afforded by § 121’s safe harbor. As a result, we vacate the grant of summary judgment and of JMOL of no obviousness-type double patenting of the '933, '422, and '349 patents and remand to the district court the question of whether the asserted claims of those patents are invalid for obviousness-type double patenting over the claims of the '008, '868, and '698 patents. In this context, we now address Roche’s contention that a new time frame for obviousness-type double patenting should apply in the district court on remand when it considers the validity of the '933, '422, and '349 patents, and in our review of the district court’s decision on the validity of the '868 and '698 patents. Roche finds support for the new time frame in our recent decision in Takeda Pharmaceutical Co. v. Doll, 561 F.3d 1372 (Fed.Cir.2009), which post-dates the district court’s decision in this case. C Takeda presented the situation where a patent applicant sought to overcome a double patenting rejection of a process patent over a product patent by presenting post-invention evidence of alternative processes of making the product. 561 F.3d at 1375-76. In 1974, Takeda Pharmaceutical Co. (“Takeda”) filed a Japanese patent application disclosing a product (cephem compounds) and the process for making the product. Id. at 1373. Takeda obtained a patent on the product in 1981, and a patent on the process in 1996, both of which claimed priority to the 1974 application. Id. at 1373-74. During reexamination of the process patent, the PTO examiner rejected the claims of the process patent as patentably indistinct over the claims of the product patent, and, therefore, invalid for double patenting, a ruling which the Board of Patent Appeals and Interferences affirmed. Id. at 1374. The District Court for the District of Columbia disagreed, however, based primarily on MPEP § 806.05(f), which provides that process and product claims are patentably distinct if “the product as claimed can be made by another materially different process.” Takeda Pharm. Co. v. Dudas, 511 F.Supp.2d 81, 96 (D.D.C.2007), vacated, Takeda, 561 F.3d at 1378. The district court held that, because viable, alternative processes for making the product existed in 2002 and 2005, the process and product were patentably distinct, and, therefore, not invalid for obviousness-type double patenting. Takeda, 511 F.Supp.2d at 97. The question on appeal to this court in Takeda was whether, when an issued patent claims a product and discloses, but does not claim, a process for making that product, the patentee, when later seeking a patent on the disclosed process, may present evidence of post-invention, alternative processes that produce the patented product, in order to show that the process and product are patentably distinct. 561 F.3d at 1375-76. The answer was a qualifled yes. We concluded that “the relevant time frame for determining whether a product and process are ‘patentably distinct’ should be at the filing date of the secondary application,” which is the later application for the process. Id. at 1377. We reasoned that “[t]he secondary application ... actually triggers the potential of an ‘unjustified extension of patent term,’ ” which is one of the “policies underlying the double patenting doctrine.” Id. That is because the patentee “essentially avers that the product and process are ‘patent-ably distinct’ ” upon filing of the secondary application. Id. Accordingly, Takeda could “rely on subsequent developments in the art up to January 8, 1990, the filing date of the secondary application, in order to show a patentable distinction between the [product and process for making the product].” Id. at 1378. We thus held that Takeda could rely on alternative processes that were in existence prior to January 8, 1990, the date of the application for the process patent. Id. It could not, however, rely on processes that came into existence after January 8, 1990, which eliminated processes existing in 2002 and 2005, which did not exist before January 8,1990. Id. Since the parties disputed whether alternative processes existed prior to the filing of the process patent, we remanded to the district court for a final obviousness-type double patenting decision. Id. Roche contends that Takeda changed the time frame for an obviousness-type double patenting analysis. Roche’s Resp. Ct. Req. 1. Roche hones in on the language in the Takeda opinion stating that “the relevant time frame for determining whether a product and process are ‘patent-ably distinct’ should be at the filing date of the secondary application.” Id. at 2 (quoting Takeda, 561 F.3d at 1377). Given this language, Roche argues that it should be able to rely on evidence up to the filing date of “secondary application[s]” to show a lack of patentable distinctiveness in this case. Id. Roche contends that interpreting Takeda’s holding so that only patentees can take advantage of post-invention developments to show a patentable distinction is manifestly unfair. Id. at 4. In Roche’s view, if the patentee is to benefit from art that arises after the invention date, then an accused infringer is likewise benefitted. Id. In other words, Roche contends, Takeda must be a two-way street, benefiting the patentee and patent challenger alike. Thus, Roche argues that evidence arising up to the time of filing of the “secondary applieation[s]” (June 7, 1995, for the '933 patent; August 2,1993, for the '422 patent; and June 6, 1995, for the '349 patent) should be considered (1) by the district court on remand in its obviousness-type double patenting analysis of the claims of the '933, '422, and '349 patents over the claims of the '008, '868, and '698 patents, and (2) by this court in its review of the obviousness-type double patenting analysis of the '868 and '698 patents over the '008 patent. Amgen responds that Takeda did not change the time frame of the obviousness-type double patenting inquiry in all cases. Amgen’s Resp. Ct. Req. 1. Amgen reads Takeda to only allow the patentee an opportunity to rely on post-invention evidence. Id. Under this reading, Takeda permits Amgen to show post-invention developments in the art that confirm patentable distinctiveness. Id. at 2. Amgen contends that, if § 121 does not shield the '933, '422, and '349 patents from obviousness-type double patenting invalidation, then Takeda permits Amgen to present evidence of alternative processes for making the products claimed in the '933, '422, and '349 patents up to the filing dates of those patents. Id. at 5. In short, Amgen contends, Takeda is a one-way street, benefitting only the patentee. Roche’s view that Takeda changed the time frame of the obviousness-type double patenting inquiry in all cases collides with 35 U.S.C. § 120. Section 120, entitled “Benefit of earlier filing date in the United States,” recites in pertinent part: An application for patent for an invention disclosed in the manner provided by the first paragraph of section 112 of this title in an application previously filed in the United States, ... which is filed by an inventor or inventors named in the previously filed application shall have the same effect, as to such invention, as though filed on the date of the prior application, if filed before the patenting or abandonment of or termination of proceedings on the first application or on an application similarly entitled to the benefit of the filing date of the first application and if it contains or is amended to contain a specific reference to the earlier filed application. 35 U.S.C. § 120 (emphases added). In short, § 120 provides that a qualifying “application for patent for an invention ... shall have the same effect ... as though filed on the date of the prior application.” This court has “repeatedly recognized [the] principle” that the “plain and unambiguous meaning of section 120 is that any application fulfilling the requirements therein ‘shall have the same effect’ as if filed on the date of the application upon which it claims priority.” Transco Prods. Inc. v. Performance Contracting, Inc., 38 F.3d 551, 556 (Fed.Cir.1994). “The ‘effect’ described in section 120 is the benefit of the earlier filing date — i.e., the benefit for purposes of priority and section 112....” Cooper Techs. Co. v. Dudas, 536 F.3d 1330, 1342 (Fed.Cir.2008). Thus, § 120 requires continuation applications to receive, at the very least, the benefits provided by the earlier filing date. We cannot read Takeda in the manner for which Roche advocates without violating the plain language of 35 U.S.C. § 120. Section 120 requires that all five of Amgen’s asserted patents (’933, '422, '349, '868, and '698) benefit from the effect of having been filed on the filing date of the '298 application, which is November 30, 1984. That means that Amgen’s patents cannot be invalidated based on art arising after November 30, 1984. Consequently, we must reject Roche’s contention that it should be able to show patentable indistinctiveness by relying on evidence up to the filing date of “secondary application[s].” Therefore, on remand, Roche may not rely on developments in the art subsequent to November 30, 1984, but pri- or to the filing dates of the '933 patent (June 7, 1995), '422 patent (August 2, 1993), and '349 patent (June 6, 1995), to show that that the '933, '422, and '349 patents are patentably indistinct over the '008 patent. The question of impairment of a patentee’s rights under § 120, as applied to foreign applicants via 35 U.S.C. § 119, did not arise in Takeda. Rather, the Takeda decision conferred upon the patentee an additional benefit outside the mandate of § 120. Nevertheless, the Takeda court understood the interrelationship between § 120 and the timing rule it created. It recognized that the rule it crafted could “provide the patentee with the best of both worlds: the applicant can use the filing date as a shield, enjoying the earlier priority date in order to avoid prior art, and rely on later-developed alternative processes as a sword to defeat double patenting challenges.” Takeda, 561 F.3d at 1377. Because of § 120, we read Takeda to stand for the limited proposition that an applicant can only rely on subsequent developments in the art up to the filing date of the “secondary application” in order to show that alternative processes to make the product render the product and the process for making that product patentably distinct. The claims of the '933 and '422 product patents, which we hold are not protected by the § 121 safe harbor, are related to the claims of the '868 and '698 process patents, although not in precisely the same way the claims of the product and process patents were related in Takeda. That is to say, the '933 and '422 patents claim products which are made by processes claimed in the '868 and '698 patents. The '349 patent differs, however, from the '933 and '422 patents in its relationship to the '868 and '698 patents because it, like the '868 and '698 patents, claims a process of producing recombinant EPO. The relationship between the '933 and '422, but not the '349, claims and the '868 and '698 claims implicates the principle applied in Takeda, 561 F.3d at 1375, that “double patenting is not sustainable when the product can be fabricated by processes other than that secured by the issued process patent.” In re Cady, 22 C.C.P.A. 1190, 77 F.2d 106, 109 (1935) (quotation marks omitted); see also MPEP § 806.05(f). On remand, Talceda will permit Amgen, if it wishes to do so, to rely on alternative processes for making the products claimed in the '933 and '422 patents up to their filing dates to prove that the claims of those patents and the claims of the '868 and '698 patents are patentably distinct. If Amgen pursues that course, Roche will be free to rely on subsequent developments in the art up to the filing dates of the '933 and '422 patents to prove that any alternative processes put forth by Amgen do not render the claims of the '933 and '422 patents and the claims of the '868 and '698 patents patentably distinct. In other words, Takeda is a two-way street within its own confines. D Turning now to the process patents, the court granted Amgen JMOL that claims 1 and 2 of the '868 patent and claims 6-9 of the '698 patent are not invalid for obviousness-type double patenting over claim 27 of the '008 patent. Amgen, 581 F.Supp.2d at 186. Since the parties had agreed that the § 121 safe harbor did not apply to these claims, the court engaged in an obviousness-type double patenting analysis. Id. at 182-83. The court first construed the claims in the '008, '868, and '698 patents and then determined that there were patentable differences. Id. The relevant claim of the '008 reference patent is claim 27, which depends from claims 7, 8, 11, and 23-25. Those claims recite as follows: 7. A purified and isolated DNA sequence consisting essentially of a DNA sequence encoding a polypeptide having an amino acid sequence sufficiently duplicative of that of erythropoietin to allow possession of the biological property of causing bone marrow cells to increase production of reticulocytes and red blood cells, and to increase hemoglobin synthesis or iron uptake. 8. A cDNA sequence according to claim 7. 11. A genomic DNA sequence according to claim 7. 23. A procaryotic or eucaryotic host cell transformed or transfected with a DNA sequence according to claim 7, 8, or 11 in a manner allowing the host cell to express said polypeptide. 24. A transformed or transfected host cell according to claim 23 which host cell is capable of glycosylating said polypeptide. 25. A transformed or transfected mammalian host cell according to claim 24. 27. A transformed or transfected CHO cell according to claim 25. '008 patent col.40 11.18-25, 30, 56-64, 67-68. In short, claim 27 recites a CHO cell — a mammalian cell capable of glycosylating EPO — transfected with a DNA sequence encoding a polypeptide having an amino acid sequence sufficiently duplicative of that of EPO to allow possession of the stated biological properties. The asserted claims of the '868 patent are independent claim 1 and dependent claim 2, which recite as follows: 1. A process for the production of a glycosylated erythropoietin polypeptide having the in vivo biological property of causing bone marrow cells to increase production of reticulocytes and red blood cells comprising the steps of: (a) growing, under suitable nutrient conditions, mammalian host cells transformed or transfected with an isolated DNA sequence encoding human erythropoietin; and (b) isolating said glycosylated erythropoietin polypeptide therefrom. 2. The process according to claim 1 wherein said host cells are CHO cells. '868 patent col.40 11.24-37. In short, claims 1 and 2 cover a process of producing EPO that involves (a) growing mammalian (CHO in claim 2) cells transfected with DNA encoding EPO and (b) isolating from those cells glycosylated EPO having the stated biological properties in vivo (i.e., in live animals). The asserted claims of the '698 patent are independent claim 6 and dependent claims 7-9, which recite as follows: 6. A process for the production of a glycosylated erythropoietin polypeptide having the in vivo biological property of causing bone marrow cells to increase production of reticulocytes and red blood cells comprising the steps of: a) growing, under suitable nutrient conditions, vertebrate cells comprising amplified DNA encoding the mature erythropoietin amino acid sequence of FIG. 6; and b) isolating said glycosylated erythropoietin polypeptide expressed by said cells. 7. The process of claim 6 wherein said vertebrate cells further comprise amplified marker gene DNA. 8. The process of claim 7 wherein said amplified marker gene DNA is Dihydrofolate reductase (DHFR) gene DNA. 9. The process according to claims 2, 4 and 6 wherein said cells are mammalian cells. '698 patent col.38 11.50-64. Claims 6-9 of the '698 patent are similar to claims 1 and 2 of the '868 patent, but with an additional limitation that the host cells comprise amplified DNA (which includes a marker gene in claim 7 that is DHFR in claim 8). The district court determined that the asserted claims in the '868 and '698 patents were patentably distinct from claim 27 of the '008 patent. The court identified the following differences between the asserted claims of the '868 and '008 patents: “Unlike the asserted claims of the '868 patent, none of the '008 claims require: (1) that the recited host cell actually express any EPO polypeptide; (2) that the recited host cell actually express a glycosylated EPO polypeptide; (3) that the host cell be capable of producing an isolatable amount of a glycosylated EPO polypeptide; and (4) that any glycosylated EPO isolated from cells grown in culture have the stated in vivo function.” Amgen, 581 F.Supp.2d at 184 (quoting Pi’s Mem. Supp. No Obviousness-Type Double Patenting [Doc. 1310] at 41). Citing the declaration testimony of Amgen’s expert, Dr. Harvey F. Lodish, the court deduced that “[s]imply having the starting material (which is reflected in the '008 patent) and knowing that, in theory, it can be used to create proteins is not the equivalent of having an actual process that successfully does so.” Amgen, 581 F.Supp.2d at 184. For similar reasons, the court concluded that claims 6-9 of the '698 patent were also patentably distinct over the claims of the '008 patent. Id. at 186. It determined that “[t]o be able to produce [a glycosylated, in vivo biologically active EPO product] from cells containing multiple copies of EPO DNA would have been novel to one skilled in the art at the time of the invention (even if the skilled artisan had possession of the product claimed in the '008 patent).” Id. The court also noted that the “PTO found the '868 and '698 claims patentably distinct from those in the '008 patent.” Id. From there, the court concluded: “The credible evidence shows, and the Court so finds, that each invention claimed in the '868 and '698 asserted claims is patentably distinct from each invention claimed in the '008 patent.” Id. On appeal, Roche contends that claims 1 and 2 of the '868 patent and claims 6-9 of the '698 patent are obvious over claim 27 of the '008 patent. Roche’s Br. 28. Roche characterizes claim 27 of the '008 patent as drawn to host cells capable of expressing a glycosylated EPO polypeptide that “allowls] possession” of in vivo biological EPO activity. Id. In turn, it characterizes claims 1 and 2 of the '868 patent and claims 6-9 of the '698 patent as drawn to processes for producing in host cells EPO “having” that stated activity. Id. Roche argues that this difference — “having” rather than “allowing] possession” of the stated activity — is not a patentable distinction. Id. In Roche’s view, “having” in vivo activity is obvious if the originally claimed host cells “allow possession” of such activity. Id. Roche also argues that claim 27 of the '008 patent created a reasonable expectation that an ordinarily skilled artisan could successfully practice the processes described in the asserted claims of the '868 and '698 patents. Id. at 31. Claim 27 of the '008 patent evidences on its face a reasonable expectation of success, according to Roche, because it “allow[s] possession” of biologically active EPO' — the invention recited in the asserted claims of the '868 and '698 patents. Roche’s Reply Br. 8. In addition, Roche argues that Dr. Lodish’s testimony demonstrates that an ordinarily skilled artisan would have had a reasonable expectation of success of producing biologically active EPO in CHO cells. Id. Specifically, Roche highlights Dr. Lodish’s testimony that a person of ordinary skill in the art could use claim 27’s host cells to express a functional protein “without any difficulty.” Id. (quoting Trial Tr. vol. 2, 109, Oct. 4, 2007). Lastly, Roche points to Dr. Lin’s admission that he expected that the claim 27 host cells would have in vivo activity. Id. at 9-11 (citing Trial Tr. vol 12, 1884, Sept. 27, 2007). Amgen responds that claim 27 of the '008 patent does not render obvious claims 1 and 2 of the '868 patent or claims 6-9 of the '698 patent. Amgen’s Br. 25. Amgen argues that, contrary to Roche’s contention, the host cells recited in claim 27 of the '008 patent do not inevitably produce the biologically active EPO required by the asserted claims of the '868 and '698 patents. Id. Amgen emphasizes that it is not the host cells that “allow possession of’ the stated biological activities; rather, it is the amino acid sequence encoded by the DNA recited in claim 27. Id. at 28. This distinction is critical, in Amgen’s view, because there is a vast difference between a CHO cell equipped to produce a polypeptide whose amino acid sequence may permit possession of certain biological activity, and a process that produces a human glycoprotein that actually possesses that activity. Id. at 29. In other words, Amgen argues that while an EPO polypeptide sequence might be necessary, it alone would not be sufficient to produce an EPO product with the stated biological activities. Id. Amgen also argues that an ordinarily skilled artisan in 1983-84 would not have reasonably expected the host cells in claim 27 of the '008 patent to produce the isolatable, biologically active EPO required by the asserted claims of the '868 and '698 patents. Id. at 32. According to Amgen, before 1984, it was not known whether any recombinant cell — including non-human CHO cells — could be engineered to produce a human EPO glycoprotein with in vivo biological activity. Id. Amgen points out that Dr. Lodish testified at trial that, before 1984, no one had successfully produced any recombinant human glycoprotein where the carbohydrate structures were required for biological activity. Id. at 38 (citing Trial Tr. vol. 2, 83, 102-103, Oct. 4, 2007). As a result, Amgen contends, skilled artisans could not have reasonably expected CHO cells to produce a biologically active EPO glycoprotein. Id. We agree with the district court that claims 1 and 2 of the '868 patent and claims 6-9 of the '698 patent are not invalid for obviousness-type double patenting over claim 27 of the '008 patent. The obviousness-type double patenting analysis entails two steps: (1) construction of the claims in the earlier patent and the claim in the later patent to identify any differences, and (2) determination of whether the differences in subject matter between the claims render the claims patentably distinct. See Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 968 (Fed.Cir. 2001). Accordingly, we begin our obviousness-type double patenting analysis, as the district court’s analysis began, by construing the claims and identifying any differences. As mentioned, claim 27 of the '008 patent recites a CHO cell — a mammalian cell capable of glycosylating EPO — transfected with a DNA sequence encoding a polypeptide having an amino acid sequence sufficiently duplicative of that of EPO to allow possession of the stated biological properties. Claims 1 and 2 of the '868 patent and claims 6-9 of the '698 patent recite processes of producing EPO that involve (a) growing mammalian cells transfected with DNA encoding EPO and (b) isolating from those cells glycosylated EPO having the stated biological properties. In essence, claim 27 of the '008 patent recites the starting materials necessary to execute the processes recited in the asserted claims of the '868 and '698 patents. The cells described in claim 27 are “capable of glycosylating” EPO and are transfected with DNA encoding a polypeptide “having an amino acid sequence sufficiently duplicative of that of erythropoietin to allow possession” of the stated biological activities. Neither of these limitations in claim 27, however, requires that the cells actually produce isolatable amounts of glycosylated EPO having the stated in vivo bioactivity. In contrast, the asserted claims of the '868 and '698 patents do require actual production of isolatable amounts of the in vivo biologically active EPO glycoprotein. In addition to possessing the transfected CHO cells recited in claim 27 of the '008 patent, an ordinarily skilled artisan practicing the asserted claims of the '868 and '698 patents would need to grow those cells and isolate from them glycosylated EPO having the stated in vivo biological properties. Thus, the main difference between claim 27 of the '008 patent and the asserted claims of the '868 and '698 patents is the actual production of isolatable glycosylated EPO having the stated in vivo biological activities. Next, we must determine whether this difference renders claims 1 and 2 of the '868 patent and claims 6-9 of the '698 patent patentably distinct over claim 27 of the '008 patent. In so doing, we ask whether the identified difference renders the claims of the '868 and '698 patents non-obvious to a person of ordinary skill in the art in light of the prior art. See In re Kaplan, 789 F.2d 1574, 1580 (Fed.Cir. 1986). This part of the obviousness-type double patenting analysis is analogous to an obviousness analysis under 35 U.S.C. § 103, except that the '008 patent is not considered prior art. See In re Longi, 759 F.2d 887, 892 n. 4 (Fed.Cir.1985) (“[A] double patenting of the obviousness type rejection is analogous to [a failure to meet] the non-obviousness requirement of 35 U.S.C. § 103, except that the patent principally underlying the double patenting rejection is not considered prior art.” (quotation marks omitted)). An obviousness determination requires that a skilled artisan would have perceived a reasonable expectation of success in making the invention in light of the prior art. See In re Kubin, 561 F.3d 1351, 1360 (Fed.Cir.2009) (“[S]tated in the familiar terms of this court’s longstanding case law, the record shows that a skilled artisan would have had a resoundingly ‘reasonable expectation of success’ in deriving the claimed invention in light of the teachings of the prior art.”); In re O’Farrell, 853 F.2d 894, 904 (Fed.Cir.1988) (“For obviousness under § 103, all that is required is a reasonable expectation of success.”); see also Longi, 759 F.2d at 896-97 (holding that a patent application was properly rejected for obviousness-type double patenting where the prior art references indicated a reasonable expectation of success). At trial, Roche had the burden of showing by clear and convincing evidence that a person of ordinary skill in the art in possession of the transfected CHO cells would have had a reasonable expectation of success in producing a recoverable amount of in vivo biologically active EPO. See PharmaStem Therapeutics, Inc. v. Viacell, Inc., 491 F.3d 1342, 1360 (Fed.Cir.2007) (“[T]he burden falls on the patent challenger to show by clear and convincing evidence that a person of ordinary skill in the art would have had reason to ... carry but the claimed process, and would have had a reasonable expectation of success in doing so.”). Whether an ordinarily skilled artisan would have reasonably expected success in practicing the asserted claims of the '868 and '698 patents is measured as of the date of the inventions described in those patents. See Life Techs., Inc. v. Clontech Labs., Inc., 224 F.3d 1320, 1326 (Fed.Cir.2000) (measuring reasonable expectation of success from the perspective of a person of ordinary skill in the art at the time the invention was made). In our view, the identified difference between the asserted claims of the '868 and '698 patents and claim 27 of the 'Ó08 patent renders the claims patentably distinct. We conclude that the actual production of glycosylated EPO having the stated in vivo biological activities would not have been obvious to an ordinarily skilled artisan in possession of the transfected CHO cells described in claim 27. That is because one of ordinary skill in the art would not have reasonably expected to successfully produce isolatable quantities of glycosylated EPO having the stated biological activities in transfected CHO cells. Put most simply, CHO cells transfected with the EPO DNA sequence and the production of recombinant, in- vivo biologically active EPO glycoprotein are patentably distinct inventions. We reach this conclusion in light of Dr. Lodish’s declarations and testimony at trial, which demonstrate that an ordinarily skilled artisan would not have reasonably expected success in producing recombinant, in vivo biologically active EPO in CHO cells. According to Dr. Lodish, there are at least two reasons why, prior to Dr. Lin’s inventions, a person of ordinary skill in the art would not have had a reasonable expectation of practicing the asserted claims of the '868 and '698 patents: (1) an ordinarily skilled artisan would not have known which, if any, host cells would produce EPO with the carbohydrate structures necessary for its in vivo function; and (2) no one had successfully produced any recombinant glycoprotein with in vivo bioactivity where the carbohydrate structures were important for biological activity. Trial Tr. vol. 2, 83, 102-04, Oct. 4, 2007. As a result, Dr. Lodish testified, an ordinarily skilled artisan would have had “great uncertainty in the ability to make recombinant EPO with carbohydrate chains for in vivo biological activity.” Trial Tr. vol. 2, 96, Oct. 4, 2007. According to this testimony and declarations to the same effect, we conclude, like the district court concluded, that a person of ordinary skill in the art would not have reasonably expected to successfully isolate from transfected CHO cells recombinant EPO glycoprotein having the stated biological activities. Roche has pointed to no prior art reference or testimony that demonstrates that an ordinarily skilled artisan would have reasonably expected to successfully produce in CHO cells an in vivo biologically active glycoprotein, much less EPO, where the carbohydrate structures matter for biological activity. Instead, Roche emphasizes Dr. Lin’s personal expectation and Dr. Lodish’s testimony that claim 27’s host cells would and do express glycosylated EPO having the stated biological properties. Neither piece of evidence persuades us that an ordinarily skilled artisan would have reasonably expected such results. First, Dr. Lin’s personal expectations are not conclusive of an ordinarily skilled artisan’s reasonable expectations. See Standard Oil Co. v. Am. Cyanamid Co., 774 F.2d 448, 454 (Fed.Cir.1985) (“[0]ne should not go about determining obviousness under § 103 by inquiring into what patentees (i.e., inventors) would have known or would likely have done, faced with the revelations of references.”). Second, Dr. Lodish’s observation that the transfected CHO cells recited in claim 27 do produce glycosylated EPO having the stated biological activity is one of hindsight, not of reasonable expectation of success at the time of the invention. See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 421, 127 S.Ct. 1727, 167 L.Ed.2d 705 (2007) (“A factfinder should be aware ... of the distortion caused by hindsight bias and must be cautious of arguments reliant upon ex post reasoning.”). Therefore, the district court did not erroneously conclude that