- Merck Sharp & Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Oct 15, 2026 · PGR2025-00030 · APJ Susan L C Mitchell · PGR · Final written decision
Claims 1, 2, and 6–30 are unpatentable under §112(a) for lack of written description and lack of enablement; the §103 ground was not reached.
RulingsFinal written decision- Additional discoveryAdditional discovery, deniedDenied
“Patent Owner filed a Motion for Additional Discovery (Paper 42), Petitioner opposed the motion (Paper 44), and the Board denied the motion (Paper 47).” slip op. at 3
- Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)Term construed board ownOther
“of the ’758 patent supports an understanding that some activity is required for a polypeptide to be a “modified PH20 polypeptide,” and it is the enzymatic activity of hyaluronidase specifically that is the most frequently identified activity recited in the Definitions section of the ’758 patent. Indeed, both the definitions of “PH20” and “modified PH20 polypeptide” require hyaluronidase activity. See Ex. 1001, 45:54–55, 50:39–41 (“PH20 refers to a type of hyaluronidase that . . . is neutral-active” and “neutral active refers to the ability . . . to enzymatically catalyze the cleavage of hyaluronic acid at neutral pH”); 48:43–46 (“A modified PH20 polypeptide can have up to 150 amino acid replacements so long as the resulting modified PH20 polypeptide exhibits hyaluronidase activity.”). Similar language is used later in the definition of a “conjugate” to explain that even when the modified PH20 polypeptide is linked to another polypeptide or chemical moiety it “retains hyaluronidase activity.” Id. at 63:39–46. In contrast, the discussion regarding the potential use of “modified PH20 polypeptides that are inactive” as antigens in contraception vaccines appears only in non-definitional sections of the ’758 patent. Id. at 72:63–65, 75:60–62. Accordingly, we find that this disclosure does not modify the definition’s explicit requirement that the claimed “modified PH20 polypeptide” exhibit hyaluronidase activity. Id. at 48:38–46.” slip op. at 21
- Skill levelOther
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 9
- Expert testimonyPetitioner expert creditedPatent owner expert discountedDecided for petitioner
“this testimony to at most describe a research plan (i.e., a “tool to engage in further modification”16) for finding the recited polypeptides rather than demonstrating the inventors were in possession of the full scope claimed. This is particularly so given the limits of the then-available analytical tools noted above and the fact that the structural connections and three dimensional modeling Patent Owner’s experts attempt to make (see, e.g., Ex. 2070 ¶¶ 129–213; Ex. 2068 ¶¶ 123–125) do not appear in the written description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. See Ex. 1133 ¶¶ 111–251 (identifying problems with the approaches proposed by Patent Owner’s experts). For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple mutants retained hyaluronidase activity, even with the single substitution data provided by the ’758 patent.” slip op. at 56
Patent outcomesUS 12,054,758 unpatentableClaim construction§ 103 obviousness§ 112 disclosurecites Phillips · KSR · GrahamPatents in suitUS 12,054,758 - Merck Sharp & Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Oct 15, 2026 · PGR2025-00024 · APJ Susan L C Mitchell · PGR · Final written decision
Claims 1, 2, 6–15, and 17–30 are unpatentable under §112(a) for lack of written description and enablement; the §103 ground was not reached.
RulingsFinal written decision- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“this testimony to at most describe a research plan (i.e., a “tool to engage in further modification”16) for finding the recited polypeptides rather than demonstrating the inventors were in possession of the full scope claimed. This is particularly so given the limits of the then-available analytical tools noted above and the fact that the structural connections and three dimensional modeling Patent Owner’s experts attempt to make (see, e.g., Ex. 2070 ¶¶ 129–213; Ex. 2068 ¶¶ 123–125) do not appear in the written description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. See Ex. 1133 ¶¶ 111–250 (identifying problems with the approaches proposed by Patent Owner’s experts). For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple mutants retained hyaluronidase activity, even with the single substitution data provided by the ’590 patent.” slip op. at 56
- Disclosure Requirements (§112) › Enablement (Wands, Amgen full scope)Not enabledUnpatentable
“6. Analysis Petitioner has the burden to identify how the Specification allegedly” slip op. at 75
- Obviousness (§103) › Motivation to combine / reasonable expectation of successNot reached
“4. Analysis Based on the evidence of record, we agree with Patent Owner that Petitioner has not provided any persuasive reason to particularly target the leucine at position 307 of a PH20 polypeptide for modification as recited in claim 1 of the ’590 patent. It is undisputed that neither of the cited prior art references, the ’429 patent or Chao, specifically identifies or discusses position 307 of the PH20 polypeptide. See, e.g., Pet. 88‒109; PO Resp. 86‒ 93. We are not persuaded by Petitioner’s argument that multiple sequence alignments identify amino acids that are tolerated at particular positions (see Pet. 99‒109), because tolerance is not a positive reason to make a substitution. “It is not enough, even after KSR, to support a determination of obviousness that a reference includes a broad generic disclosure and a common utility to that in the claims and other prior art references—there must be some reason to select a species from the genus.” Knauf Insulation, Inc. v. Rockwool Int’l A/S, 788 F. App’x 728, 733 (Fed. Cir. 2019). Dr. Park identified 379 positions in PH20 (i.e., ~85% of the protein) with evolutionary variation, that is, where “homologous proteins have tolerated different amino acids at those positions.” Ex. 1004 ¶ 31. Dr. Park distributes the twenty standard amino acids into four categories depending on their roles in forming secondary structure such as alpha helices or beta sheets, with each category having a minimum of six members. See id. ¶ 70. Nothing in the prior art or Dr. Park’s analysis directs the ordinary artisan to position 307 itself. Although Dr. Hecht asserts that the ’429 patent suggests conservative mutations generally, Petitioner did not point us to any specific teaching or” slip op. at 126
- Additional discoveryAdditional discovery, deniedDenied
“Patent Owner filed a Motion for Additional Discovery (Paper 41), Petitioner opposed the motion (Paper 43), and the Board denied the motion (Paper 46).” slip op. at 3
Patent outcomesUS 12,060,590 unpatentable§ 103 obviousness§ 112 disclosurecites Phillips · KSR · GrahamPatents in suitUS 12,060,590 - Merck Sharp & Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Oct 2, 2026 · PGR2025-00046 · APJ Jeffrey N Fredman · PGR · Final written decision
Claims 1, 2, 5, and 7–33 are unpatentable because the Petitioner proved lack of written description and lack of enablement; the Board did not find the claims obvious.
RulingsFinal written decision- Skill levelSkill level petitioner adoptedDecided for petitioner
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 8
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“been able to use the data in the Specification to make reasonable predictions about the effect of multiple modifications on hyaluronidase activity, we view this testimony to at most describe a research plan (i.e., a “tool to engage in further modification”15) for finding the recited polypeptides rather than demonstrating the inventors were in possession of the full scope claimed. This is particularly so given the limits of the then-available analytical tools noted above and the fact that the structural connections and three dimensional modeling Patent Owner’s experts attempt to make (see, e.g., Ex. 2070 ¶¶ 129–213; Ex. 2068 ¶¶ 123–125) do not appear in the written description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. See Ex. 1133 ¶¶ 111–230 (identifying problems with the approaches proposed by Patent Owner’s experts). For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple” slip op. at 54
- Disclosure Requirements (§112) › Enablement (Wands, Amgen full scope)Not enabledUnpatentable
“6. Analysis Petitioner has the burden to identify how the Specification allegedly” slip op. at 74
- Obviousness (§103) › Graham factors (scope of art, differences, level of skill)Not shown unpatentableNot shown unpatentable
“E. Ground III - Obviousness 1. Principles of Law The Supreme Court in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398” slip op. at 117
Patent outcomesUS 12,091,692 unpatentable§ 103 obviousness§ 112 disclosurecites Phillips · KSR · GrahamPatents in suitUS 12,091,692 - Merck Sharp & Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Oct 1, 2026 · PGR2025-00052 · APJ Cynthia M Hardman · PGR · Final written decision
Claims 1–17 are unpatentable for lack of written description, lack of enablement, and indefiniteness; the Board did not find them unpatentable as obvious.
RulingsFinal written decision- Skill levelOther
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 7
- Claim Construction › Intrinsic evidence (Phillips canons) › Plain and ordinary meaning to a POSITATerm construed board ownDecided for petitioner
“Specification of the ’345 patent supports an understanding that some activity is required for a polypeptide to be a “modified PH20 polypeptide,” and it is the enzymatic activity of hyaluronidase specifically that is the most frequently identified activity recited in the Definitions section of the ’345 patent. Indeed, the definitions of “PH20” and “modified PH20 polypeptide” both require hyaluronidase activity. See Ex. 1001, 44:20–21, 49:4–7 (“PH20 refers to a type of hyaluronidase that . . . is neutral-active” and “neutral active refers to the ability . . . to enzymatically catalyze the cleavage of hyaluronic acid at neutral pH”); 47:8–11 (“A modified PH20 polypeptide can have up to 150 amino acid replacements so long as the resulting modified PH20 polypeptide exhibits hyaluronidase activity.”). Similar language is used later in the definition of a “conjugate” to explain that even when the modified PH20 polypeptide is linked to another polypeptide or chemical moiety it “retains hyaluronidase activity.” Id. at 61:60–67. In contrast, the discussion regarding the potential use of “modified PH20 polypeptides that are inactive” as antigens in contraception vaccines appears only in non-definitional sections of the ’345 patent. Id. at 71:16-18, 74:11–13. Accordingly, we find that this disclosure does not modify the definition’s explicit requirement that the claimed “modified PH20 polypeptide” exhibit hyaluronidase activity. Id. at 47:3–11.” slip op. at 20
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“description (see Capon, 418 F.3d at 1357–58), Patent Owner is trying to extend that to include that which is at most obvious from the prior art, as opposed to what is actually described. That is, it may have been obvious to a POSA to align PH20 sequences with other known hyaluronidase enzymes and to use the crystal structure of a different hyaluronidase (Hyal-1) in SWISS-MODEL to generate a three-dimensional structure, but none of that is described in the common disclosure itself. “[A] description that merely renders the invention obvious does not satisfy the [written description] requirement.” Ariad, 598 F.3d at 1352. While a POSA might be able to embark on their own research program to try to find suitable multiply-modified PH20 polypeptides, the four corners of the written description do not demonstrate possession of such. See id. at 1356‒57 (recognizing that “[p]erhaps one of ordinary skill could discover this information, but this does not alter our conclusion that the description . . . just represent[s] a wish or arguably a plan for future research”) (internal quotation omitted).” slip op. at 66
- Disclosure Requirements (§112) › Enablement (Wands, Amgen full scope)Not enabledUnpatentable
“instances of epistasis are “rare” and an inactive PH20 polypeptide “will stay inactive . . . absent intentional ‘rescue’ mutations.” See Sur-reply 12–14. But the claims encompass far more than combinations of just two substitutions, and even Dr. Petsko concedes there are “billions” of sequences within the recited sequence space that will not properly fold. See Ex. 2070 ¶ 347; see also Ex. 1133 ¶ 237 (“While some [residues critical to protein structure] can be predicted (e.g., highly conserved positions), many others cannot without experimentation.”). Accordingly, we find Petitioner’s position more persuasive than Patent Owner’s competing position and evidence.” slip op. at 108
Patent outcomesUS 12,264,345 unpatentableClaim construction§ 103 obviousness§ 112 disclosurecites Phillips · KSR · Graham · NautilusPatents in suitUS 12,264,345 - Merck Sharp And Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Sep 25, 2026 · PGR2025-00039 · APJ Michael A Valek · PGR · Final written decision
Claims 1–4 and 7–11 are unpatentable because the challenged claims lack written-description support and are not enabled.
RulingsFinal written decision- Adverse judgmentAdverse judgmentOther
“1 Although the Petition was directed to claims 1–11 of the ’185 patent, Patent Owner filed a statutory disclaimer of claims 5 and 6 prior to institution, leaving just claims 1–4 and 7–11 at issue. See Ex. 2003.” slip op. at 2
- Skill levelOther
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 9
- Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)Other
“B. Claim Construction In a post-grant review, we interpret a claim “using the same claim” slip op. at 11
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“For these reasons, we find that a preponderance of the evidence” slip op. at 59
Patent outcomesUS 12,104,185 unpatentableClaim construction§ 103 obviousness§ 112 disclosurecites KSR · GrahamPatents in suitUS 12,104,185 - Merck Sharp And Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Sep 25, 2026 · PGR2025-00033 · APJ Michael A Valek · PGR · Final written decision
Claims 1, 2, and 6–29 are unpatentable for lack of written description and enablement; the Board did not find them obvious over the ’429 patent and Chao.
RulingsFinal written decision- Expert testimonyPetitioner expert creditedDecided for petitioner
“structural connections and three-dimensional modeling Patent Owner’s experts attempt to make (see, e.g., Ex. 2070 ¶¶ 126–212, 297–342; Ex. 2068 ¶¶ 123–125, 245, 294–313, 318) do not appear in the written description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. See Ex. 1133 ¶¶ 111–230 (identifying problems with the approaches proposed by Patent Owner’s experts). For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple mutants retained hyaluronidase activity, even with the single substitution data provided by the ’652 patent.” slip op. at 58
- Skill levelOther
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 8
- Claim Construction › Intrinsic evidence (Phillips canons) › Lexicography (patentee as own lexicographer)Decided for petitioner
“exclude the use of modified PH20 polypeptides as contraceptives—the only other possible utility described in the ’652 patent—is unavailing. Resp. 39. First, “[t]he fact that a patent asserts that an invention achieves several objectives does not require that each of the claims be construed as limited to structures that are capable of achieving all of the objectives.” Phillips, 415 F.3d at 1327 (citing Liebel–Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 908 (Fed. Cir. 2004)). Second, unlike the definitions of “PH20” and “modified PH20 polypeptide” in the “Definitions” section of the Specification, the passages describing possible contraceptive use do not contain any characteristics suggesting they are definitional in nature. See Alnylam, 138 F.4th at 133 (enumerating “characteristics” such as the fact that the text appears in the “Definitions” section, sets the term off in quotation marks, and uses phrases like “refer to” that indicate that specification language is definitional in nature). Accordingly, the statement that “[a]lso provided are modified PH20 polypeptides that are inactive, and that can be used, for example, as antigens in contraception vaccines” (Ex. 1001, 75:56–58), does not redefine the term, nor otherwise void the definitional language in the Specification stating that a “modified PH20 polypeptide can have up to 150 amino acid replacements, so long as the resulting modified PH20 polypeptide exhibits hyaluronidase activity.” Id. at 48:47–49 (emphasis added).” slip op. at 26
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“1352. While a POSA might be able to embark on their own research program to try to find the genus of multiply-modified PH20 polypeptides recited in the challenged claims, the four corners of the written description here do not demonstrate the inventors were in possession of such. See id. at 1356–57 (recognizing that “[p]erhaps one of ordinary skill could discover this information, but this does not alter our conclusion that the description . . . just represent a wish or arguably a plan for future research”) (internal quotation omitted).” slip op. at 68
Patent outcomesUS 12,049,652 unpatentableClaim construction§ 103 obviousness§ 112 disclosurecites Phillips · KSR · GrahamPatents in suitUS 12,049,652 - Charles River Laboratories, Inc. v. Seikagaku CorporationAll claims unpatentablePTAB · Sep 8, 2026 · PGR2025-00023 · APJ Per Curiam · PGR · Final written decision
Claims 1–9 are unpatentable as anticipated by the ’629 publication; the claims are not entitled to the 2013 priority date.
RulingsFinal written decision- Skill levelSkill level board ownOther
“We find that a rigid requirement as to the subject of a POSITA’s doctoral degree (e.g., biochemical engineering, enzymology), or experience working specifically with horseshoe crab proteins, is not consistent with the evidence of record. See, e.g., Ex. 1067, 20:23–21:2 (Dr. Schaefer testifying that the fact the “name of [his] Ph.D. is immunology . . . does not change the fact that the core of [his] thesis training was really in molecular biology”), 22:3–15 (explaining that “the fact that the production of proteins recombinantly is mostly species agnostic”); Ex. 1069, 45:20–47:17 (Dr. Morris testifying that whether a person is a POSITA depends on the person’s “experience, [ ] publications,” and work done for the Ph.D. rather than the name of the Ph.D. program). We also find that evidence of record supports Petitioner’s assertion that, for purposes of defining a POSITA, “[m]ore education could substitute for experience, and vice versa.” See, e.g., Pet. 22; Ex. 1065, 99:14–100:3. Accordingly, based on the entirety of the trial record, we find a POSITA with respect to the claims of the ’109 patent would have had a two years of experience with cloning genes, expressing cloned genes as proteins, and/or characterizing such cloned genes and proteins, with more education being able to substitute for experience, and vice versa. A POSITA may also have collaborated with others, including those with specific experience in utilizing or assessing horseshoe crab Factor C for endotoxin detection and quantitation.” slip op. at 9
- Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther
“Neither party proposes an express construction of any claim term. See Pet. 22–23 (not proposing any constructions); PO Resp. 23 (“Patent Owner agrees that the terms can be afforded their plain and ordinary meaning.”). However, Patent Owner states that some of Petitioner’s arguments implicitly construe claim 1 in an erroneous manner. PO Resp. 23–28. “For example, Petitioner argues that ‘an adequate written description would have to either disclose representative examples of the possible working cascades of various proteins or some accurate structural feature of the claimed proteins that allow them to function in the claimed assay as a whole.’” Id. at 23 (quoting Pet. 35). Patent Owner argues that, contrary to what Petitioner’s argument allegedly implies, “Claim 1 is directed to a method for producing an endotoxin assay agent” and does not require the use – Owner that claim 1 does not require the use of endotoxin assay agent. However, the claimed endotoxin assay agent must be capable of performing the assay, as counsel for Patent Owner acknowledged. Tr. 83:5–9.” slip op. at 10
- BurdenNot shown unpatentable
“In this case, to show that the claims of the ’109 patent are unpatentable for lack of written description, Petitioner would have needed to show that the specification as filed (i.e., the ’420 application) fails to reasonably convey to those skilled in the art that Patent Owner had possession of the claimed subject matter as of the July 3, 2023, filing date. Petitioner did not. Pet. 23–24. Nor does Petitioner’s declarant offer testimony that could support such a showing. See Ex. 1003 ¶50 (“I have been asked to provide my opinions as to the state of the art in this field for purposes of determining what the inventors disclosed as their invention as of December 10, 2013.”), ¶51 (“Whenever I offer an opinion in this declaration about the knowledge of a POSA, the manner in which a POSA would have understood the claims of the ’109 patent or its description, the manner in have been led to do based on the prior art, I am referencing the December 10, 2013 timeframe.”). In our Institution Decision, we stated: Although the ’420 application is essentially identical to the ’767 application, the person of ordinary skill in 2013 is not the same as in 2023. See Ariad, 598 F.3d at 1351 (“[T]he [written description] test requires an objective inquiry into the four corners of the specification from the perspective of a person of ordinary skill in the art.” (emphasis added)). Thus, the information presented in the Petition, which is limited to the perspective of a 2013 POSITA, does not demonstrate that it is more likely than not that at least 1 of the claims challenged in the Petition is unpatentable for lack of written description. Inst. Dec. 12 (alterations in original). During trial, Petitioner did not present any further arguments in support of Ground 1. See generally Pet. Reply. Petitioner has failed to prove that claims 1–9 are unpatentable for failing to meet the written description requirement set forth in 35 U.S.C. § 112(a).” slip op. at 12
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateNot shown unpatentable
“Although the evidence before us shows that, in 2013, a POSITA knew how to recombinantly express genes in expression systems such as CHO or HEK-293 cell lines, the evidence shows that this was true only for genes whose genetic sequences were known or readily available. See, e.g., Ex. 1069, 34:11–22 (“Q. Okay. So you would agree that the creation of the recombinant protein requires the underlying sequence of, as you said, the original animal? A. Of course.”) Because it is undisputed that, in 2013, the genetic sequence for Limulus polyphemus Factor C was unknown, or least not publicly available, Falko-Gunter does not support a finding of adequate written description here. See, e.g., Tr. 48:18–19 (“Patent Owner agrees that there had not been, as of 2013, the full length cDNA sequence for Limulus polyphemus Factor C published.”).” slip op. at 23
Patent outcomesUS 11,959,109 unpatentableClaim construction§ 102 anticipation§ 112 disclosurePatents in suitUS 11,959,109 - Charles River Laboratories, Inc. v. Seikagaku CorporationAll claims unpatentablePTAB · Sep 8, 2026 · IPR2025-00440 · APJ Tawen Chang · IPR · Final written decision
Claim 21 is unpatentable as obvious over Mizumura with either the ’498 PCT or McClymont; the Revised Contingent Motion to Amend proposing claim 22 is denied.
RulingsFinal written decision- Skill levelSkill level patent owner adoptedDecided for patent owner
“overlap to a significant degree, i.e., a person with a Ph.D. in a discipline related to biological sciences and having had at least two years of work experience. However, the parties’ proposals differ slightly in the specific subjects in which a POSA would have had a doctoral degree, and whether the person’s work experience must have been directly related to horseshoe crab Factor C. As an initial matter, we find that a rigid requirement as to the subject of a POSA’s doctoral degree (e.g., biochemical engineering, enzymology), or experience working specifically with horseshoe crab proteins, is not consistent with the evidence of record. See, e.g., Ex. 1067, 20:23–21:2 (Dr. Schaefer testifying that the fact the “name of [his] Ph.D. is immunology . . . does not change the fact that the core of [his] thesis training was really in molecular biology”), 22:3–15 (explaining “the fact that the production of proteins recombinantly is mostly species agnostic”); Ex. 1069, 45:20–47:17 (Dr. Morris testifying that whether a person is a POSA depends on the person’s “experience, [ ] publications,” and work done for the Ph.D. rather than the name of the Ph.D. program). We also find that evidence of record supports Petitioner’s assertion that, for purposes of defining a POSA, “[m]ore education could substitute for experience, and vice versa.” See, e.g., Pet. 19; Ex. 1065, 99:14–100:3. with respect to the claims of the ’318 patent would have had a Ph.D. in molecular biology, biochemistry, or a related discipline, and about two years of experience with cloning genes, expressing cloned genes as proteins, and/or characterizing such cloned genes and proteins, with more education being able to substitute for experience, and vice versa. A POSA may also have collaborated with others, including those with specific experience in utilizing or assessing horseshoe crab Factor C for endotoxin detection and quantitation.” slip op. at 13
- Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther
“C. Claim Construction The parties agree that “the terms in claim 21 can be afforded their plain and ordinary meaning for purposes of this proceeding” without further construction. Pet. 19–20; PO Resp. 11. Because express claim construction is not needed to resolve the issues in this case, we need not, and do not, construe expressly any claim term for purposes of this Decision. See Realtime Data, LLC v. Iancu, 912 F.3d 1368, 1375 (Fed. Cir. 2019) (“The Board is required to construe ‘only those terms . . . that are in controversy, and only to the extent necessary to resolve the controversy.’”) (quoting Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999)).” slip op. at 14
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateNot entitled to earlier dateDecided for petitioner
“Carrying Out the Invention section, that “[t]he Factor C of the present invention is a Factor C derived from a horseshoe crab,” and states later in the same section that “[e]xamples of the horseshoe crab include . . . Limulus polyphemus.” Ex. 1006, 40. However, none of the remaining portions of ’767 application cited by Patent Owner relate directly to L. polyphemus; instead, the remaining portions of ’767 application cited by Patent Owner are directed to other species, in particular the Japanese horseshoe crab T. tridentatus. Further, Patent Owner’s witness, Dr. Schaefer, conceded that the ’767 application does not contain Factor C sequence information for L. polyphemus. See, e.g., Ex. 1067, 44:25–45:23. Although “[n]o length requirement exists for a disclosure to adequately describe an invention,” Falko-Gunter, 448 F.3d at 1365–1366, we are persuaded that a POSA would not, based on the totality of the above disclosures, reasonably understand that the inventors were in possession of the claimed HEK-293 recombinant L. polyphemus Factor C protein, in view of the state of the art as of December 10, 2013. In this regard, we note that adequate written description of a biological molecule, such as a HEK293 recombinant L. polyphemus Factor C protein, requires “more than a mere statement that it is part of the invention and reference to a potential method for isolating it”; instead, what is required is “‘a precise definition, such as by structure, formula, chemical name, or physical properties,’ not a mere wish or plan for obtaining the claimed chemical invention.” The Regents of the” slip op. at 21
- Obviousness (§103) › Motivation to combine / reasonable expectation of successMotivation foundReasonable expectation foundDecided for petitioner
“Pfizer, Inc. v. Apotex, Inc., 480 F.3d 1348, 1364 (Fed. Cir. 2007). Neither do we see Petitioner’s arguments regarding the December 10, 2013 priority date to be “mutually opposed” as Dr. Schaefer testified. Ex. 1067, 216:4– 24. Instead, we credit evidence of record, including Dr. Jain’s testimony and the February 22, 2018 Mizumura Declaration, that existence of the full sequence would permit a more complete analysis and that such an analysis would provide a POSA with a reasonable expectation that the claimed L. polyphemus recombinant protein would have a residual activity within the claimed range. See, e.g., Ex. 1029, 2–5; Ex. 1010, 48; Ex. 1065, 117:14– 130:24 (explaining that comparison of partial sequences in the Tokunaga 1991 publication showed “difference around the cleavage site” between T. tridentatus and L. polyphemus but comparison of the full sequence revealed that “the catalytic triad of histidine, serine, aspartate . . . to be more similar between Tachypleus and Limulus”). Patent Owner asserts that “Petitioner’s reliance on a statement made by Dr. Mizumura in a declaration submitted during prosecution of the ’767 Application fails to fill the gap in the analysis” regarding reasonable expectation of success, because the declaration “offers no evidence of the percentage of conserved amino acid substitutions that exist to support the conclusion that a POSA would have expected residual activity to be maintained between Tachypleus tridentatus and Limulus polyphemus” PO Resp. 47. However, as noted above, Dr. Mizumura provides an alignment of Factor C proteins from the two different species of horseshoe crab, determines that the similarity between the amino acid sequence is 99.5%, states that the amino acid residues that can undergo N-type sugar chain that L. polyphemus, like T. tridentatus, would also be less susceptible to inhibition by ions. Ex. 1029, 4–5. For the reasons discussed above, we also disagree with Patent Owner’s assertion that Petitioner’s reasonable expectation of success argument is “nothing more than conclusory assertions with no support.” PO Resp. 46. Rather, we find Petitioner has shown, by a preponderance of the evidence, that a POSA would have had reason to combine the teachings of Mizumura and the ’498 PCT, with a reasonable expectation of success in arriving at the Factor C protein recited in claim 21.” slip op. at 38
Patent outcomesUS 11,236,318 unpatentableClaim construction§ 103 obviousness§ 112 disclosurecites KSR · GrahamPatents in suitUS 11,236,318 - Merck Sharp & Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Sep 1, 2026 · PGR2025-00017 · APJ Jeffrey N Fredman · PGR · Final written decision
Claims 1, 2, 6–15, and 17–30 are unpatentable because the challenged claims lack written-description support and are not enabled.
RulingsFinal written decision- Skill levelSkill level petitioner adoptedDecided for petitioner
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 9
- Expert testimonyPetitioner expert creditedPatent owner expert discountedDecided for petitioner
“been able to use the data in the Specification to make reasonable predictions about the effect of multiple modifications on hyaluronidase activity, we view this testimony to at most describe a research plan (i.e., a “tool to engage in further modification”14) for finding the recited polypeptides rather than demonstrating the inventors were in possession of the full scope claimed. This is particularly so given the limits of the then-available analytical tools noted above and the fact that the structural connections and three dimensional modeling Patent Owner’s experts attempt to make (see, e.g., Ex. 2070 ¶¶ 129–213; Ex. 2068 ¶¶ 123–125) do not appear in the written description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. See Ex. 1133 ¶¶ 111–230 (identifying problems with the approaches proposed by Patent Owner’s experts). For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple” slip op. at 53
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“been able to use the data in the Specification to make reasonable predictions about the effect of multiple modifications on hyaluronidase activity, we view this testimony to at most describe a research plan (i.e., a “tool to engage in further modification”14) for finding the recited polypeptides rather than demonstrating the inventors were in possession of the full scope claimed. This is particularly so given the limits of the then-available analytical tools noted above and the fact that the structural connections and three dimensional modeling Patent Owner’s experts attempt to make (see, e.g., Ex. 2070 ¶¶ 129–213; Ex. 2068 ¶¶ 123–125) do not appear in the written description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. See Ex. 1133 ¶¶ 111–230 (identifying problems with the approaches proposed by Patent Owner’s experts). For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple” slip op. at 53
- Disclosure Requirements (§112) › Enablement (Wands, Amgen full scope)Not enabledUnpatentable
“an enzyme has folded,” Dr. Naismith states, “there would need to be additional evidence to justify a conclusion that the folded enzyme is sufficiently stable to retain its folded state” and “a POSA would not believe an enzyme had ‘properly folded’ if it did not maintain activity over a meaningful period or if it formed aggregates within a short period.” Id. ¶ 59.” slip op. at 78
Patent outcomesUS 12,110,520 unpatentable§ 103 obviousness§ 112 disclosurecites Phillips · KSR · GrahamPatents in suitUS 12,110,520 - Merck Sharp & Dohme LLC v. Halozyme, Inc.All claims unpatentablePTAB · Jun 24, 2026 · PGR2025-00009 · APJ Susan L C Mitchell · PGR · Final written decision
Claims 1, 2, 6–14, and 16–29 are unpatentable based on written description, enablement, and obviousness grounds.
RulingsFinal written decision- Director reviewDirector review, deniedDenied
“Following institution, Patent Owner filed a Director Review Request (Paper 33), and Petitioner filed an Authorized Response (Paper 37), and the then-Acting Director issued a denial of the Director Review Request. Paper 40.” slip op. at 3
- Additional discoveryAdditional discovery, deniedDenied
“(Paper 46, “PO Resp.”), Petitioner filed a Reply to Patent Owner’s Response (Paper 71, “Pet. Reply”), and Patent Owner filed a Sur-reply (Paper 84, “PO Sur-reply”). Patent Owner filed a motion for additional discovery (Paper 62), Petitioner opposed the Motion for Discovery (Paper 63), and the Board denied the Motion for Discovery (Paper 77).” slip op. at 3
- Skill levelSkill level petitioner adoptedDecided for petitioner
“II. ANALYSIS A. Level of Ordinary Skill in the Art We consider the grounds of unpatentability in view of the” slip op. at 8
- Disclosure Requirements (§112) › Written description (Ariad)Written description inadequateUnpatentable
“description itself. To the extent the experts disagree on this point, we credit the testimony of Petitioner’s experts over that of Patent Owner’s. For these reasons, we find that a preponderance of the evidence of record better supports a finding that in the 2011–2012 timeframe, it would have been unpredictable to identify which multiple mutants retained hyaluronidase activity, even with the single substitution data provided by the ’035 patent.” slip op. at 53
Patent outcomesUS 12,123,035 unpatentable§ 103 obviousness§ 112 disclosurecites Phillips · KSR · GrahamPatents in suitUS 12,123,035
Holdings, summaries, rulings, issues, outcomes, winners and claim constructions shown for a decision were generated by a large language model reading the opinion. They are a guide to the decision, not the decision. Confirm every one against the court's own text before relying on it. Outcomes read from the patent owner’s side. Party names are extracted from the decision and are missing on about 900 short Director denials and scans, which carry the trial number instead.