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Complex or Not Written Description Is Evaluated Against Claims

by Connor M. Larson | Jan 23, 2025 | Patents

The US Court of Appeals for the Federal Circuit reversed a district court’s ruling of invalidity for lack of written description, finding that the district court erred in its analysis of written description because patents must be evaluated based on the claims themselves, not on their construction. In re Entresto, Case No. 23-2218 (Fed. Cir. Jan. 10, 2025) (Lourie, Prost, Reyna, JJ.)

Novartis owns an approved new drug application (NDA) for a combination therapy of valsartan and sacubitril that Novartis markets under the brand name Entresto®. The term “combination therapy” is used to describe pharmaceuticals where two or more active pharmaceutical ingredients are combined in a single method of treatment. Entresto® is protected by several patents, including the patent at issue. Several generic pharmaceutical manufacturers, including MSN, filed abbreviated new drug applications (ANDAs) seeking to market generic versions of Entresto® prior to the expiration of Novartis’ patent. Novartis sued for infringement.

A unique property of Entresto® is the specific form taken by the active pharmaceutical ingredients, valsartan and sacubitril. The valsartan and sacubitril in Entresto® are present in what is known as a “complex,” meaning the two drugs are bonded together by weak, noncovalent bonds. At issue before the district court was the construction of the claim term “wherein said [valsartan and sacubitril] are administered in combination.” The inquiry focused on whether “in combination” required the valsartan and sacubitril to be chemically separated molecules (not in the form of a complex). The district court adopted Novartis’ proposal to give the term its plain and ordinary meaning because the intrinsic record was silent as to whether the molecules must be separate and not complexed. The complexed form of valsartan and sacubitril was not developed until four years after the priority date of the patent.

After the district court declined to adopt MSN’s “complexed” claim construction, MSN stipulated to infringement. The case proceeded to a bench trial on the issue of validity. The district court found the patent not invalid for obviousness, lack of enablement, and indefiniteness. However, the district court ruled that because the patent did not disclose the complexed form of valsartan and sacubitril, it was invalid for lack of written description. Novartis appealed.

Novartis argued that a complex of valsartan and sacubitril was an after-arising invention that need not have been enabled or described. The Federal Circuit agreed, finding that because the patent did not claim the complexed form of valsartan and sacubitril, those complexes need not have been described. The Court cited its “long-recognized” rule that “the invention is, for purposes of the written description inquiry, whatever is now claimed.” All that was required to meet the written description requirement was a disclosure sufficient to show that the inventors possessed a pharmaceutical composition comprising valsartan and sacubitril administered in combination. The Federal Circuit found that by considering what the claims were “construed to cover,” the district court improperly conflated the distinct issues of patentability and infringement. The Federal Circuit reversed the district court’s finding of invalidity for lack [...]

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PTO Continues to Wave Wands in Assessing Enablement

by Christopher M. Bruno | Jan 18, 2024 | Patents

In light of the 2023 Supreme Court of the United States decision in Amgen Inc. v. Sanofi, the US Patent & Trademark Office (PTO) published guidelines for PTO employees to use, regardless of technology, to ascertain compliance with the enablement requirement under 35 U.S.C. § 112. (89 Fed. Reg. 1563 (Jan. 10, 2024).) Unsurprising to those familiar with the Amgen decision, the PTO hewed closely to existing practice.

The PTO collected the Supreme Court’s clarifications regarding the relationship between the enablement requirement and an amount of experimentation, namely that although particular disclosure of all embodiments is not required, claims are not enabled if they require more than reasonable experimentation. Regarding the “reasonable experimentation” requirement, the PTO explained that consistent with several post-Amgen US Court of Appeals for the Federal Circuit opinions, it would continue to apply the factors that the Federal Circuit announced in its 1988 In re Wands decision.

Although the PTO intends to continue to rely on pre-Amgen Federal Circuit Wands analyses as instructive, it found particular persuasive force since the Federal Circuit’s decision was affirmed by the Supreme Court in Amgen. There, according to the guidance, the Federal Circuit concluded that the genus claims were not enabled because of the amount of experimentation required to test whether antibodies satisfied certain functional limitations. Thus, because “the scope of the claims was far broader in functional diversity than the disclosed examples, … [and] the invention was in an unpredictable field of science with respect to satisfying the full scope of the functional limitations, … there was not adequate guidance in the specification.”

The PTO also noted that the Federal Circuit’s 2023 Baxalta v. Genentech decision, like Amgen, found claims directed to antibodies that contained certain functional limitations to be invalid. There, the Court, like the PTO, detected no appreciable difference between the reasonable experimentation standard as articulated in Wands and the standard as set forth in Amgen. The guidance canvassed other post-Amgen enablement decisions, all of which the PTO read to support continued reliance on Wands.

Practice Note: Although the PTO says that it will continue to apply the Wands factors as it has before, the Amgen decision may, as a practical matter, make establishing enablement of functional limitations more difficult. Whether examiners—especially those in life sciences technology areas—change the course of their review post-Amgen remains to be seen.

Beware Enablement of Genus Antibody Claims

by Jayita Guhaniyogi, PhD | Oct 5, 2023 | Patents

The US Court of Appeals for the Federal Circuit invalidated yet another set of antibody genus claims, finding the case “materially indistinguishable” from those in the 2023 Supreme Court of the United States case, Amgen v. Sanofi. The Federal Circuit concluded that patent claims covering a class of antibodies targeting functions of blood clotting factors were invalid for lack of enablement, echoing the reasoning followed by fellow Circuit Judge Dyk, who sat by designation in the district court. Baxalta Inc. and Baxalta GMBH v. Genentech, Inc., Case No. 2022-1461 (Fed. Cir. Sept. 20, 2023) (Moore, Clevenger, Chen, JJ.)

This case involves Baxalta’s patent covering antibody preparations that bind to blood clotting Factors IX/IXa and thereby increase the procoagulant activity of Factor IXa. This in turn activates another blood clotting factor, Factor X, that is useful to treat hemophilia, particularly in patients who develop inhibitors to blood clotting Factor VIII. The claim at issue recited “[a]n isolated antibody or antibody fragment thereof that binds Factor IX or Factor IXa and increases procoagulant activity of Factor IXa.”

Baxalta sued Genentech for infringement. In a prior appeal involving claim construction, the Federal Circuit vacated the district court’s grant of summary judgment of noninfringement and remanded for further proceedings. On remand, the district court granted Genentech’s motion for summary judgment for lack of enablement. Baxalta appealed.

Baxalta challenged the summary judgment of invalidity on enablement. Baxalta argued that a skilled artisan could make the full scope of the claimed antibodies without undue experimentation. With reference to the subject patent’s disclosure of using a prior art method known as the hybridoma technique for generating Factors IX/IXa antibodies, Baxalta argued that using routine screenings to find the antibodies exhibiting the claimed functions (i.e., those that bind Factors IX/IXa and increase procoagulant activity of Factor IXa) was within the skill of a skilled artisan without undue experimentation.

The Federal Circuit, citing Amgen, explained that the enablement standard under Section 112(a) requires that “the specification [] enable the full scope of the invention as defined by its claims,” allowing for “a reasonable amount of experimentation.” The Court explained that in Amgen, the patents at issue generically claimed all antibodies that bind to specific amino acid residues on a protein and blocked the protein from binding to LDL receptors. The Court observed that while the Amgen patent disclosed amino acid sequences of 26 antibodies, the claim scope could cover millions. Similarly, the Amgen patent disclosed a roadmap and another conservative substitution method for generating new antibodies and testing them for the claimed functions. In Amgen, the Supreme Court held that such methods were nothing more than “trial-and-error experimentation,” which, in the absence of “some general quality . . . running through the class that gives it a peculiar fitness for the particular purpose,” failed to enable the full scope in that case.

The Federal Circuit found the facts in this case “materially indistinguishable” from Amgen. Like the claims at issue in Amgen, Baxalta’s patent claims all [...]

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Holy Pulmonary Hypertension, Batman: Method of Treatment Not Constrained by Safety and Efficacy

by Nitya Anand | Aug 3, 2023 | Patents

The US Court of Appeals for the Federal Circuit affirmed a district court’s holding that the asserted method of treatment patent was valid and infringed because safety and efficacy are not patent concerns. The Federal Circuit also affirmed the district court’s holding that certain claims of the product-by-process patent were invalid because the claimed product was in the prior art, regardless of the process by which it was made. United Therapeutics Corporation v. Liquidia Technologies, Inc., Case Nos. 22-2217; 23-1021 (Fed. Cir. July 24, 2023) (Lourie, Dyk, Stoll, JJ.)

United Therapeutics is the maker of Tyvaso®, a treprostinil formulation approved for treating pulmonary hypertension. United Therapeutics asserted two patents covering Tyvaso® against Liquidia’s § 505(b)(2) new drug application (NDA) on Yutrepia™. One patent was a method of treatment patent claiming to treat pulmonary hypertension by administering a “therapeutically effective” dose of a treprostinil formulation, and the other was a product-by-process patent claiming a treprostinil composition with lowered levels of impurities made by a specific salt formation process.

The district court found that United Therapeutics showed that a single administration of treprostinil improves a patient’s hemodynamics, establishing that administration of Liquidia’s Yutrepia, comprising treprostinil, would directly infringe the method of treatment claims. The district court also concluded that even though Yutrepia’s label did not provide hemodynamic data, the label’s instructions would inevitably lead to the administration of a therapeutically effective single event dose. The court thus concluded that Liquidia would induce infringement of the method of treatment claims.

The district court further found that the asserted claims were not invalid for lack of enablement or written description. The court reasoned that a skilled artisan would not need to engage in undue experimentation to practice the full scope of the claimed treatment of pulmonary hypertension, despite potential safety concerns in treating certain patients, since the claims did not require safety and efficacy. The court found that the claims were not invalid for lack of written description, finding that a skilled artisan would, based on the specification, understand that treprostinil would effectively vasodilate the pulmonary vasculature, improve hemodynamics and treat a patient’s elevated pulmonary blood pressure.

Liquidia appealed on five issues: claim construction of the term “treating pulmonary hypertension,” enablement, written description, induced infringement and infringement of the product by process claims. United Therapeutics cross-appealed on anticipation of the product by process claims and non-infringement of those claims.

First, regarding the construction of “treating pulmonary hypertension,” the Federal Circuit affirmed that the term encompassed all recognized groups of pulmonary hypertension but noted that the claim language “treating pulmonary hypertension” did not import any additional efficacy limitations or safety limitations, even those in a group that would not benefit from the treatment. The Court declined to read any safety or efficacy requirements into the claims, explaining that absent incorporation into the claims, the safety and efficacy of a claimed treatment are the purview of the US Food & Drug Administration (FDA), not patent law.

Regarding enablement and written description, Liquidia argued that the method [...]

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Reaching New Lights: Inherent Upper Limit Enables Open-Ended Range

by Amol Parikh | Apr 27, 2023 | Patents

The US Court of Appeals for the Federal Circuit affirmed an International Trade Commission decision finding a § 337 violation. The Court concluded that the Commission correctly found that an open-ended claim was enabled since there was an inherent upper limit and correctly construed the term “a” to mean “one or more” in finding infringement. FS.com Inc. v. International Trade Commission, Case No. 22-1228 (Fed. Cir. Apr. 20, 2023) (Moore, Prost, Hughes, JJ.)

Corning Optical Communications owns several patents directed to fiber optic technology. Corning alleged that FS violated § 337 by importing high-density fiber optic equipment that infringed the patents. In assessing infringement, the Commission construed the claim term “a front opening” to mean “an opening located in the front side of a fiber optic module (e.g., the opening depicted in Figure 13 of the [asserted] patent as having dimensions H1 and W1”) and further concluded that the term encompassed one or more openings. The Commission found that FS’s products met this requirement and therefore infringed. FS argued that certain claims were invalid because they were not enabled. The claims at issue recited “a fiber optic connection density of at least ninety-eight (98) fiber optic connections per U space” or “a fiber optic connection of at least one hundred forty-four (144) fiber optic connections per U space.” FS argued that these open-ended density ranges were not enabled because the specification only enabled up to 144 fiber optic connections per U space. The Commission rejected FS’s invalidity argument. FS appealed.

The Federal Circuit affirmed the Commission’s enablement determination. The Court explained that open-ended claims are not inherently improper and may be enabled “if there is an inherent, albeit not precisely known, upper limit and the specification enables one of skill in the art to approach that limit.” The Court found that there was an inherent upper limit of about 144 connections per U space since skilled artisans would have understood that densities substantially above 144 connections per U space were technologically infeasible. The Court further found that the specification disclosed that the maximum density achievable was 144 connections per U space and expert testimony confirmed that, despite market pressure, no commercial product has achieved a density greater than 144 connections. Considering this evidence, the Court concluded that the Commission properly found that the open-ended claims had an inherent upper limit of about 144 connections per U space and the claimed open-ended range was therefore enabled.

The Federal Circuit also affirmed the Commission’s infringement determination. The Court explained that the terms “a” or “an” in a patent claim generally mean “one or more,” unless the patentee evinces a clear intent to limit “a” or “an” to “one.” FS argued that the recitation of “front openings” in an unasserted claim showed a clear intent to limit “a front opening” in the asserted claim to a single opening. The Court rejected that argument, finding that limiting an unasserted claim to multiple openings did not show an intent to limit the asserted claim to [...]

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Sleep Better: Amendments Proposed during IPR Deemed Proper and Valid

by Rodney Swartz, PhD | Nov 29, 2022 | Patents

The US Court of Appeals for the Federal Circuit affirmed the Patent Trial & Appeal Board’s (Board) finding that proposed amendments made during an inter partes review (IPR) are valid and proper despite the inclusion of changes not related to patentability issues raised in the petition. Nat’l Mfg., Inc. v. Sleep No. Corp., Case No. 21-1321 (Fed. Cir. Nov. 14, 2022) (Stoll, Schall, Cunningham, JJ.)

We’ve likely all seen the commercials promising a proven quality of sleep. Sleep Number is the owner of numerous patents, including several directed to methods for adjusting “the pressure in an air mattress ‘in less time and with greater accuracy’ than previously known.” The patents state this is achieved by taking pressure measurements at the valve enclosure and applying a pressure adjustment factor that is iteratively revised using an “adjustment factor error.” The patent states that this method allows for monitoring the pressure of the air mattress without the need to turn off the pumps.

American National Manufacturing challenged the validity of the patents in an IPR proceeding, claiming that most were rendered obvious by the prior art of Gifft in view of Mittal and Pillsbury and that six of the dependent claims requiring a “multiplicative pressure adjustment factor” would have been obvious in further view of Ebel. Gifft disclosed an air-bed system using valve assembly pressure to approximate the air chamber pressure and Mittal and Pillsbury both disclosed using additive offsets to improve accuracy. Ebel disclosed using both additive and multiplicative components to accurately measure the actual pressure in an inflating or deflating air bag.

The Board agreed with American National that it would have been obvious to combine Gifft, Mittal and Pillsbury and that the resulting combination rendered most of the claims obvious, but it also noted that the combination failed to show that a “skilled artisan would have applied Ebel’s multiplicative factors” to the prior art. However, in each proceeding Sleep Number filed a motion to amend the claims contingent on a finding that the challenged claims were unpatentable. The proposed claims included the “multiplicative pressure adjustment factor” that the Board had determined was not unpatentable along with other non-substantive changes.

American National took issue with these amendments, arguing they were legally inappropriate, non-enabled because of an error in the specification and lacked written description support. The Board disagreed. American National appealed. Sleep Number cross-appealed the Board’s finding of obviousness.

The Federal Circuit found that the proposed amendments were not improper even though some of the changes were non-substantive changes to address consistency issues. The Court pointed out that “once a proposed claim includes amendments to address a prior art ground in the trial, a patent owner also may include additional limitations to address potential § 101 or § 112 issues, if necessary.” The Court rejected American National’s argument that permitting such amendments creates an “asymmetrical” and “unfair” proceeding “by allowing the patent owner and the Board to address concerns that may be proper for [an] examination or reexamination proceeding, but that [...]

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Another Genus Claim Bites the Dust for Lack of Written Description

by Mandy H. Kim | Sep 9, 2021 | Patents

Addressing the issue of written description in the context of antibody-related genus claims, the US Court of Appeals for the Federal Circuit reversed a $1.2 billion jury verdict and found genus claims using functional language invalid for lack of written description. Juno Therapeutics, Inc. v. Kite Pharma, Inc., Case No. 20-1758 (Fed. Cir. Aug. 26, 2021) (Moore, J.)

Kite’s YESCARTA® is a therapy in which a patient’s T cells are engineered to express a chimeric antigen receptor (CAR) to target the antigen CD19. Juno sued Kite, alleging infringement of a patent relating to a nucleic acid polymer encoding a three-part CAR for a T cell. The three-part CAR comprises:

An intracellular domain of the CD3 ζ (zeta) chain, a signaling domain that is activated to create an initial immune response
A costimulatory region comprising of a specific amino acid sequence (here, a specific CD28 sequence) that, when activated, directs the T cells to multiply
A binding element that determines what target molecule or antigen the CAR can bind to, such as a single-chain antibody variable fragment (scFV).

Juno’s patent disclosed two scFVs (one that binds CD19 and another that binds PSMA) but did not disclose the amino acid sequence of either scFV.

After a two-week trial, the jury reached a verdict in Juno’s favor, finding in relevant part that Kite failed to prove that any of the asserted claims were invalid for lack of written description or enablement. The jury awarded damages amounting to a $585 million upfront payment and an almost 28% running royalty. The district court denied Kite’s motions for judgment as a matter of law and enhanced the total award to approximately $1.2 billion in addition to the 28% running royalty. Kite appealed.

The Federal Circuit reversed, concluding that no reasonable jury could find adequate written description because the patent disclosed neither representative species nor common structural features of the claimed scFV genus to identify which of the millions of billions of scFVs would function as claimed. Turning first to lack of representative species, the Court explained that the broadest asserted claims cover any scFV that binds to any target of clinical interest but fails to provide a representative sample of species within, or defining characteristics for, that expansive genus. The Court also disagreed that the two working embodiments in the patent were representative of the entire genus of vast number of possible scFVs that bind to an undetermined number of targets without more in the disclosure (such as the characteristics of the exemplary scFVs that allow them to bind to particular targets or nucleotide sequences). The Court stated that even if such scFVs were known as Juno argued, the specification provided no means of distinguishing which scFVs would bind to which targets.

Turning next to lack of structural features common to the claimed genus, the Federal Circuit held that general assertions that scFVs generally have a common structure in the context of the technology in this case were insufficient because an scFV with the [...]

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Knowledge of Patent, Evidence of Infringement Are Necessary, but Not Sufficient, to Establish Willfulness

by Paul Devinsky | Mar 11, 2021 | Patents

Addressing claim construction, enablement, damages and willfulness, the US Court of Appeals for the Federal Circuit found that evidence of a defendant’s knowledge of the asserted patent and proof of infringement were, by themselves, legally insufficient to support a finding of willfulness. Bayer Healthcare LLC v. Baxalta Inc., Case No. 19-2418 (Fed. Cir. Mar. 1, 2021) (Stoll, J.)

Bayer owns a patent on certain recombinant forms of human factor VII (FVIII), a protein that is critical for blood coagulation. Recombinant FVIII is useful as a treatment for coagulation disorders, primarily Hemophilia A. Natural FVIII has a short half-life, making therapeutic administration expensive and inconvenient. Adding polyethylene glycol (a process known as PEGylating) to FVIII at random sites was found to increase the protein’s half-life but reduce its function. Bayer invented FVIII that is PEGylated in a specific region (the B-domain) so that it retains its function and maintains the longer half-life.

After Baxalta developed a PEGylated FVIII therapeutic, Adynovate®, Bayer sued Baxalta for infringement of its patent. During claim construction, the district court construed the claim preamble “an isolated polypeptide conjugate” to mean “a polypeptide conjugate where conjugation was not random,” finding that Bayer had disclaimed conjugates with random PEGylation. The district court also construed “at the B-domain” to mean “attachment at the B-domain such that the resulting conjugate retains functional FVIII activity,” rejecting Baxalta’s proposal of “at a site that is not any amine or carboxy site in FVIII and is in the B-domain” because Bayer had not disclaimed PEGylation at amine or carboxy sites. Before trial, Baxalta moved for clarification of the term “random” in the construction of the preamble, but the district court “again” rejected Baxalta’s argument that Bayer defined “random” conjugation as “any conjugation at amines or carboxy sites.”

Before trial, Baxalta moved to exclude the testimony of Bayer’s damages expert regarding his proposed reasonable-royalty rate. The expert had defined a bargaining range and proposed to testify that the royalty rate should be the midpoint of the range based on the Nash Bargaining Solution. The district court permitted the expert to testify as to the bargaining range but excluded the opinions regarding the midpoint as insufficiently tied to the facts of the case.

After trial, the district court granted Baxalta’s pre-verdict motion for judgment as a matter of law (JMOL) of no willful infringement. Subsequently, the jury returned a verdict that the claims were infringed and not invalid for non-enablement, and awarded damages based on an approximately 18% royalty rate for the period for which the parties had presented sales information. Baxalta moved for JMOL or a new trial on infringement, enablement and damages. Bayer moved for pre-verdict supplemental damages for the period between the presented sales data and the date of judgment, and for a new trial on the issue of willfulness. The district court denied all of Baxalta’s motions and Bayer’s motion for new trial, but granted Bayer’s motion for supplemental damages, applying the jury’s ~18% rate to sales data for the later period. [...]

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