All posts by Holman

The Use of Mandated Public Disclosures of Clinical Trials as Prior Art Against Study Sponsors

By Chris Holman

Salix Pharms., Ltd. v. Norwich Pharms. Inc., 2024 WL 1561195 (Fed. Cir. Apr. 11, 2024)

Human clinical trials play an essential role in the discovery, development, and regulatory approval of innovative drugs, and federal law mandates the public disclosure of these trials. Pharmaceutical innovators are voicing concern that these disclosures are increasingly being used as prior art to invalidate patents arising out of, or otherwise relating to, these trials, in a manner that threatens to disincentivize investment in pharmaceutical innovation. A recent Federal Circuit decision, Salix Pharms., Ltd. v. Norwich Pharms. Inc., illustrates the concern.  In Salix, a divided panel upheld a district court decision to invalidate pharmaceutical method of treatment claims for obviousness based on a clinical study protocol published on the website. The case garnered amicus curiae briefs filed by several innovative pharmaceutical companies in support of the patent owner, Salix Pharmaceuticals. (more…)

When is the use of a product a “substantial noninfringing use” for purposes of Section 271(c)?

By Chris Holman

Sections 271(b) and 271(c) of the Patent Act form the statutory basis for the two forms of indirect patent infringement, induced and contributory, respectively. Section 271(c) explicitly provides that sale of a material that is “suitable for substantial noninfringing use” is not contributory infringement (note that this proviso does not apply to induced infringement under 271(b)). In a recent post, Dennis pointed out that in H. Lundbeck A/S v. Lupin Ltd. the Federal Circuit “somewhat controversially” states that:

[S]ubstantial noninfringing use in section 271(c) refers to uses that do not infringe the patent in question, not other patents. The text is clear: to support liability, the accused infringer must sell a material part of an invention or an article for use in practicing a patented process “knowing the same to be especially made or especially adapted for use in an infringement of such patent.” 35 U.S.C. § 271(c) (emphasis added). “Such patent” is in the singular and refers to a specific patent—the asserted patent.

Taken on its face, the statement seems overbroad and potentially problematic for the reason set forth by another Federal Circuit panel in Lucent Techs., Inc. v. Gateway, Inc., 580 F.3d 1301, 1320 (Fed. Cir. 2009):

One example illustrates the problem with Microsoft’s approach. Consider a software program comprising five—and only five—features. Each of the five features is separately and distinctly patented using a method claim. That is, the first feature infringes a method claim in a first patent, the second feature infringes a method claim in a second patent, and so forth. Assume also that the company selling the software doesn’t provide specific instructions on how to use the five features, thus taking potential liability outside the realm of § 271(b). In this scenario, under Microsoft’s position, the software seller can never be liable for contributory infringement of any one of the method patents because the entire software program is capable of substantial noninfringing use. This seems both untenable as a practical outcome and inconsistent with both the statute and governing precedent.

The dicta from Lucent seems to support the proposition that in determining whether there has been contributory infringement with respect to a first patent, a use of the product should not be deemed a “substantial noninfringing use” negating a finding of contributory infringement if that use would infringe a second patent, at least under some circumstances. But under what circumstances should this be permitted. For example, would it be proper for a court to assume that the second patent would be infringed by an alleged “substantial noninfringing use” without allowing the alleged infringer an opportunity to challenge the validity of the second patent and participate in a formal construction of the relevant claims?

This issue arose in the context of calculating lost profit damages in a 1995 decision of the en banc Federal Circuit, Rite-Hite Corp. v. Kelley Co., 56 F.3d 1538 (Fed. Cir. 1995). In that case, the district court identified essentially the same concern expressed by the Federal Circuit in Intel, stating that its decision to award lost profit damages for lost sales of a product not covered by the infringed patent “avoid[ed] the ‘whip-saw’ problem, whereby an infringer could avoid paying lost profits damages altogether by developing a device using a first patented technology to compete with a device that uses a second patented technology and developing a device using the second patented technology to compete with a device that uses the first patented technology.” In a split decision, the Federal Circuit affirmed, explaining that:

the only Panduit factor that arguably was not met in the present fact situation is the second one, absence of acceptable non-infringing substitutes. Establishment of this factor tends to prove that the patentee would not have lost the sales to a non-infringing third party rather than to the infringer[.]  Here, the only substitute for the patented device was the ADL–100, another of the patentee’s devices. Such a substitute was not an “acceptable, non-infringing substitute” within the meaning of Panduit because, being patented by Rite–Hite, it was not available to customers except from Rite–Hite. Rite–Hite therefore would not have lost the sales to a third party. The second Panduit factor thus has been met. If, on the other hand, the ADL–100 had not been patented and was found to be an acceptable substitute, that would have been a different story, and Rite–Hite would have had to prove that its customers would not have obtained the ADL–100 from a third party in order to prove the second factor of Panduit.

Writing in dissent, Judge Nies pointed out the potential problem with the majority’s approach:

[T]he one or more patents on technology used in the ADL–100 were never asserted against Kelley, and the validity of those patents is untested. If those patents are invalid, the majority’s analysis collapses.… Given that Kelley has had no legal basis for bringing a declaratory judgment action challenging the unlitigated patents (never having been charged with their infringement), the majority imposes liability and overlooks the unfairness in its theory. If the unlitigated patents are significant to damages, Kelley deserves an opportunity to defend against them. A clearer denial of due process is rarely seen.

On a related note, in Eli Lilly & Co. v. Actavis Elizabeth LLC, 435 F. App’x 917 (Fed. Cir. 2011), the Federal Circuit held that the use of a drug that has not been approved by the FDA does not constitute a “substantial noninfringing use” for purposes of 271(c). The accused infringer in this Hatch-Waxman case argued that up to 29% of the total use of the drug in question was off-label and noninfringing, and the patent owner conceded that this noninfringing off-label use was possibly as high as 8%. But the Federal Circuit found this used to be irrelevant for purposes of 271(c), holding that “unauthorized activity does not avoid infringement by a product that is authorized to be sold solely for the infringing use.” See also Grunenthal GMBH v. Alkem Lab’ys Ltd., 919 F.3d 1333, 1340 (Fed. Cir. 2019)(“In a pharmaceutical case, the noninfringing use must be in accordance with the use for which the product is indicated.” citing Eli Lilly and Co. v. Actavis Elizabeth LLC).

Based on my review of reported decisions, contributory infringement has not played a significant role in pharmaceutical patent litigation, and is redundant in view of the availability of an action for induced infringement. There are many decisions in which an alleged infringer is found liable for both induced infringement and contributory infringement, and also a significant number of decisions in which the alleged infringer has been found liable for inducing infringement but not contributory infringement. See, e.g., Vanda Pharms. Inc. v. W.-Ward Pharms. Int’l Ltd., 887 F.3d 1117 (Fed. Cir. 2018) and In re Depomed Pat. Litig., 2016 WL 7163647 (D.N.J. Sept. 0, 2016).  However, I have searched of case law and failed to find a reported decision involving and FDA-authorized pharmaceutical in which the court found contributory infringement but held that there was not induced infringement. I found a single district court decision in which the court found that contributory infringement had been proven and did not make a finding with respect to induced infringement, declaring the issue moot in view of its finding of contributory infringement.  Alcon Rsch., Ltd. v. Apotex Inc., 790 F. Supp. 2d 868 (S.D. Ind. 2011).

A Question of First Impression: What Happens When the PTAB Fails to Meet the Statutory Deadline for Issuing a Final Written Decision?

By Chris Holman

Purdue Pharma L.P. v. Collegium Pharm., Inc., 2023 WL8043047 (Fed. Cir. Nov. 21, 2023)

Section 326(a)(11) of Title 35 (the Patent Act) provides that the PTO “shall prescribe regulations… requiring that the final determination in any post-grant review be issued not later than 1 year after [institution],” and that the time can be extended by up to six months for good cause or in the case of joinder (emphasis added).  On its face, the statute seems to establish a statutory deadline of 18 months from institution (one year plus the six-month extension) for the PTAB to issue its Final Written Decision in a post-grant review (“PGR”) proceeding.  In Purdue Pharma L.P. v. Collegium Pharm., Inc., the Federal Circuit answered a question that the court characterized as one of first impression, i.e., what recourse do the parties have if the PTAB fails to meet the statutory deadline? The Federal Circuit concluded that, because the statute does not specify any means for enforcing the PTAB’s compliance with the statutory deadline, the only recourse lies in a petition for a writ of mandamus.

The PTAB’s apparently unprecedented failure to issue its Final Written Decision within 18 months arose out of some unusual circumstances, including Purdue’s filing of a Notice of Bankruptcy Filing and Imposition of Automatic Stay and the Board’s resulting decision to stay the PGR, as well as some turnover on the panel that heard the case. In any event, after the PTAB issued its Final Written Decision finding Purdue’s claims to be unpatentable, Purdue appealed to the Federal Circuit, arguing that the Board lacked the authority to issue a Final Written Decision because it had failed to meet the 18 month deadline.

But the Federal Circuit sided with Collegium Pharma and the PTO, holding that the PTAB has authority to issue a Final Written Decision even after the deadline proscribed in the statute has passed.  The court cited Supreme Court precedent for the proposition that “if a statute does not specify a consequence for non-compliance with statutory timing provisions, the federal courts will not in the ordinary course impose their own coercive sanction.” Responding to Purdue’s argument that the use of “shall” and “requiring” in section 326(a)(11) deprives the Board of authority to issue a Final Written Decision after the deadline, the Federal Circuit noted that in Brock v. Pierce Cnty. the Supreme Court held the “requirement that the Secretary ‘shall’ take action within 120 days does not, standing alone, divest the Secretary of jurisdiction to act after that time.”

The court found it significant that other provisions of the AIA use quite different language to bar action after the passage of a deadline. Section 315(b), for example, contains explicit language denying agency power after a time deadline, saying “[a]n inter partes review may not be instituted if the petition requesting the proceeding is filed more than 1 year after the date on which the petitioner … is served with a complaint alleging infringement of the patent.” (emphasis added).  See also section 321(c) (“A petition for a postgrant review may only be filed not later than the date that is 9 months after the date of the grant of the patent or of the issuance of a reissue patent” (emphasis added)). The Federal Circuit concluded that “[h]ad Congress meant to deprive the agency of power in section 326(a)(11), it knew how to do it, and, significantly, it did not use language in section 326(a)(11) similar to that used in other sections.”

The court found further support in the AIA’s legislative history, noting that “[i]f the Board could not issue a Final Written Decision, the parties would be forced to pursue the issue in district court litigation. This is the exact opposite of the purpose of the AIA, which is meant to create a more efficient alternative to district court litigation.”

The Federal Circuit goes on to state that Purdue’s appropriate remedy would have been a petition for writ of mandamus, which “is available immediately upon the deadline’s expiring, assuming that the other requirements for issuance of the writ are satisfied. There is no requirement to show unreasonable delay in the issuance of the decision—only that the deadline has passed.”

It remains to be seen whether the Federal Circuit’s decision will result in more Final Written Decisions being issued after the expiration of the 18 month statutory deadline, and whether mandamus will prove an effective remedy.

Further Thoughts on Patent Eligibility and Predictability

By Chris Holman

I enjoyed reading the recent article by Professors Rantanen and Datzov, and was not surprised by their conclusion that the courts are generally applying the Supreme Court’s patent eligibility precedent in a relatively predictable manner. I have not conducted such a systematic review of patent eligibility decisions, but over the years I have read quite a few of them, and for some time I have felt that I can usually predict which way the court will go in deciding these cases.

The two-part Alice/Mayo framework for assessing the patent eligibility of method claims, which formally involves determining whether a patent claim is “directed towards” one of the judicial exceptions (law of nature, natural phenomenon, or abstract idea), and if so, to determine whether there is “enough” additional “inventive concept” to render the claim a patent eligible “application” of that judicial exception, seems quite indeterminate on its face. But Alice provides some important clarifying language:

[Petitioner’s method claims do not] purport to improve the functioning of the computer itself. Nor do they effect an improvement in any other technology or technical field. Instead, the claims at issue amount to nothing significantly more than an instruction to apply the abstract idea of intermediated settlement using some unspecified, generic computer. Under our precedents, that is not “enough ” to transform an abstract idea into a patent-eligible invention.

The message I have taken from this paragraph is that technological innovations, including software that “improve[s] the functioning of [a] computer,” generally remain patent eligible. And I have found that, when reading judicial decisions addressing the patent eligibility of method claims relating to computers and computer programs , if it looks and feels like the purported innovation is technological in nature, the claim is likely to be upheld. On the other hand, if the claimed method feels less technological, e.g., a method of playing bingo on the Internet, or a “business method,” I expect it to be struck down. Occasionally I am surprised by a decision, but from what I have seen the courts are generally treating the “abstract ideas” exception as a bar to the patenting of non-technological innovations.

The “natural phenomena” and “laws of nature” exceptions tend to be invoked in the context of life science innovations, and it seems to me that most method claims arising out of the life sciences will be deemed patent eligible unless the court deems it to be directed towards a “diagnostic method,” i.e., an analytical method based on the discovery of a correlation between a biomarker and some clinically significant information, e.g., a genetic sequence and the likelihood of developing cancer, or a chemical metabolite and the optimal dosage of a drug.  If a claimed method relating to the life sciences can plausibly be characterized as something other than a diagnostic claim, e.g., a method of preparing some sort of biological product, or treating a disease, etc., it is generally going to be found patent eligible.  But if the court concludes that it is a diagnostic method, it is going down.

In the Federal Circuit’s decision denying en banc rehearing of Athena Diagnostics, all of the judges on the Federal Circuit seemed to agree that, under the court’s current interpretation of Mayo, diagnostic methods are essentially patent ineligible per se. They also seem to agree that this is an unfortunate state of affairs, given the tremendous medical benefits that innovative diagnostic methods can provide, as exemplified by the claims struck down in Athena Diagnostics. The major split revealed by the various opinions dissenting and concurring with the court’s en banc decision to deny rehearing is that a majority of the judges on the Federal Circuit believe that their hands are tied by Supreme Court precedent, particularly Mayo, while a significant number of dissenting judges disagreed, arguing that the Federal Circuit had unnecessarily tied its own hands with respect to diagnostic methods, and that, properly interpreted, Mayo left open the possibility of finding at least some diagnostic methods patent eligible.

Some of the Federal Circuit judges seemed to voice approval for the way in which Alice has been deployed in the abstract idea context to invalidate claims directed towards business methods and other non-technological inventions.  On the other hand, they voiced concern that in the laws of nature/natural phenomena context Mayo was resulting in the invalidation of meritorious diagnostic method claims.  In any event, when it comes to the life sciences and method claims, the Federal Circuit seems inclined to interpret Mayo relatively narrowly, and uphold the eligibility of method claims, so long as the claimed invention can plausibly be characterized as something other than a diagnostic method.

“Bald Girls Do Lunch” Unable to Sway the Federal Circuit in Case Involving Deuterated Drug for Alopecia Areata

By Chris Holman

Sun Pharmaceutical v. Incyte, 2023 WL 5370639, Not Reported in Fed. Rptr. (Fed. Cir. Aug. 22, 2023)

Bald Girls Do Lunch (“BDGL”) is a nonprofit organization dedicated to improving the quality of life for females living with alopecia areata (“AA”).  AA has been described as “an autoimmune skin disease resulting in partial to complete hair loss on all hair-bearing areas of the body, including, for example, on the face, resulting in loss of eyebrows and eyelashes.” According to BDGL, “AA is not a simple cosmetic problem—it is a chronic, often devastating condition that has substantial and wideranging implications, affecting patient’s physical, mental, and emotional health.  Indeed, in severe cases, AA can lead to chronic depression.”

On August 22, the Federal Circuit issued a nonprecedential opinion in the case of Sun Pharmaceutical v. Incyte affirming an IPR decision that struck down as obvious all the claims in a patent directed towards a promising new treatment option for AA.  The patent is directed towards certain deuterated derivatives of ruxolitinib.  Ruxolitinib is a JAK1/JAK2 inhibitor “currently approved for the treatment of patients with intermediate or high-risk myelofibrosis.”  Deuteration involves replacing one or more hydrogen atoms of a drug with deuterium, an isotope of hydrogen, to slow the CYP-mediated metabolism of a drug or to reduce the formation of undesirable metabolites, which can result in improved safety, tolerability, or efficacy.  The claims encompass an octo-deuterated ruxolitinib analog identified as “CTP-543,” a potential treatment for AA that has been granted “Fast Track” and “Breakthrough Therapy” designations, which means that FDA will expedite its review as a new drug.

BDGL filed an amicus curiae brief in support of the patent owner, Sun Pharmaceutical, which focuses on one specific aspect of the Patent Trial and Appeal Board’s decision, i.e., the Board’s evaluation of one of the objective indicia of nonobviousness, “long-felt but unsolved need.” The Board found that while CTP-543 has the “potential” and “likelihood” of satisfying the need for an effective treatment for AA, as of now it has not actually satisfied the need for an FDA-approved treatment for AA, because it has yet to receive FDA marketing approval.

In its brief, BDGL argues that in 2012, at the time of the patent’s effective filing date, there was a long-felt, unmet need for a new treatment option for AA. No FDA-approved AA treatment existed, and off-label treatments were ineffective or not tolerable long-term, or both, and many caused unwanted side effects, ranging from unpleasant or undesirable to potentially serious. BDGL argues in its brief that the proper time for assessing the presence of a long-felt, unmet need is at the time of patent filing, and that the determination of whether that need has been satisfied should be based on the treatment as claimed in the as-filed patent application, not upon a marketed product embodying the patented invention. The organization points to the FDA’s decision to grant CTP-543 expedited review status as evidence of the long-felt, unmet need for treatment for AA patients, as well as positive results in completed Phase 3 clinical trials.

BDGL’s brief concludes by warning that the Board’s approach “threatens to upend the well-established obviousness analysis – solely with respect to patents on technology that requires premarket regulatory approval such as pharmaceutical patents – and threatens to impede the development of innovative pharmaceutical treatment necessary to care for patients, particularly for patients suffering from conditions for which no treatment otherwise exists.”

A unanimous panel of the Federal Circuit was not persuaded, however, upholding the Board’s determination with respect to objective indicia as well as its ultimate conclusion that all of the claims were obvious. The Federal Circuit explained:

Assuming, without deciding, that the need for an effective and safe alopecia areata treatment existed, the Board had substantial evidence for its finding that CTP-543 had not actually satisfied this long-felt need, but only had the “potential” and “likelihood” to do so. While we agree with Sun (and amicus Bald Girls Do Lunch) that FDA approval is not a prerequisite to showing that a long-felt need has been met, and FDA’s designation of CTP-543 for “Breakthrough Therapy” and “Fast-Track” approval are probative of nonobviousness, here Sun expressly framed its objective indicia argument as “CTP-543 satisfies the long-felt need for an FDA-approved, evidence-based alopecia areata treatment,” (emphasis added), and the Board reasonably found that CTP-543 had not met this need because it lacked FDA approval.  Thus, substantial evidence supports the Board’s conclusion that Sun did not prove that CTP-543 has satisfied this long-felt need.

Note the emphasis that the Federal Circuit places on Sun Pharmaceutical’s decision to frame the issue on appeal as whether CTP-543 had satisfied the need for an “FDA-approved” AA treatment, seeming to suggest that the outcome might have been different if Sun Pharmaceutical had simply argued that the drug had satisfied the need for a new treatment option for AA, without any explicit mention of FDA approval.  In a footnote, the court specifically notes that “evidence provided by the amicus, Bald Girls Do Lunch, but not otherwise in the record cannot be considered on appeal.”

Sun Pharmaceutical v. Incyte raises the question of whether deuterated analogs of prior art compounds will generally be found obvious. I suspect that the answer is no, and as is the case with claims directed towards enantiomers, the determination will be fact-dependent and made on a case-by-case basis. In this particular case, the Board found that the prior art references of record (which included a marketing publication issued by Concert Pharmaceuticals, the original owner of the patent) disclosed (1) that ruxolitinib is a promising drug candidate; (2) that deuteration of compounds provides the potential for improved safety, better tolerability, and enhanced efficacy; and (3) the specific locations of certain metabolic “hotspots” on ruxolitinib, which are the sites on a compound were oxidative metabolism occurs during in vivo metabolism. These “hotspots” correspond to the locations where the compounds claimed in the patent are deuterated.

I can imagine scenarios in which a deuterated analog of a prior art compound might be deemed nonobvious. For example, if the prior art did not provide sufficient motivation to deuterate the particular compound at issue, or did not identify specific metabolic “hotspots” as likely locations for deuteration. Or in some cases a court might find that there was not a reasonable likelihood of success in creating or using a particular deuterated compound.

Fortunately, this was a nonprecedential decision. Given the length of time that generally elapses between the filing and issuance of a patent and FDA approval of the corresponding patented compound, a determination of obviousness will often occur prior to FDA marketing approval. Would the outcome in this case have been different if FDA had approved CTP-543 during the intervening time between the Board decision and the Federal Circuit’s decision? If the FDA does eventually approve CTP-543, will Sun Pharmaceuticals have any avenue to revisit the issue in the courts or the PTO?


Recitation of a Previously Unappreciated Mechanism of Action Does Not Overcome Prima Facie Obviousness of Drug Combination

By Chris Holman

In re Couvaras, 2023 WL 3984753 (Fed. Cir. June 14, 2023)

A prima facie obvious combination of prior art chemical compounds can sometimes be deemed nonobvious if the result of the combination is sufficiently surprising, such as when a combination of pharmaceutical active ingredients results in an unexpected synergy. See, e.g., Sanofi-Aventis Deutschland GmbH v. Glenmark Pharms. Inc., USA, 748 F.3d 1354 (Fed. Cir. 2014).  In a recent Federal Circuit decision, In re Couvaras, Judge Lourie (writing for a unanimous panel) explains the important distinction between unexpected results in a pharmaceutical combination product as opposed to the mere recitation of an unexpected mechanism of action.

The case is an appeal of a Patent Trial and Appeal Board decision affirming an Examiner’s rejection of the claims at issue as obvious.  A representative claim recites:

11.  A method of increasing prostacyclin release in systemic blood vessels of a human individual with essential hypertension to improve vasodilation, the method comprising the steps of:

providing a human individual expressing GABA-a receptors in systemic blood vessels due to essential hypertension;

providing a composition of a dosage of a GABA-a agonist and a dosage of an ARB combined into a deliverable form, the ARB being an Angiotensin II, type 1 receptor antagonist;

delivering the composition to the human individual’s circulatory system by co-administering the dosage of a GABA-a agonist and the dosage of the ARB to the human individual orally or via IV;

synergistically promoting increased release of prostacyclin by blockading angiotensin II in the human individual through the action of the dosage of the ARB to reduce GABA-a receptor inhibition due to angiotensin II presence during a period of time, and

activating the uninhibited GABA-a receptors through the action of the GABA-a agonist during the period of time; and

relaxing smooth muscle of the systemic blood vessels as a result of increased prostacyclin release.

Judge Lourie leads off the decision by observing that, while the claims at issue “literally recite methods of increasing prostacyclin release … by co-administering two well-known types of antihypertensive agents[, i]n reality, the claims relate to combatting hypertension with known antihypertensive agents and claiming their previously unappreciated mechanism of action.”

He then affirms the Board’s conclusion that it “is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition which is to be used for the very same purpose.”  It was undisputed that the two types of active agents recited in the claims, GABA-a agonists and ARBs, were both known to be useful for alleviating hypertension.

The appellant, citing Honeywell International Inc. v. Mexichem Amanco Holdings S.A., 865 F.3d 1348, 1355 (Fed. Cir. 2017), argued that the mechanism of action recited in the claims, i.e., the increased release of prostacyclin, was unexpected, and that the Board had erred in dismissing the limitation as having no patentable weight due to inherency.  But the Federal Circuit rejected this argument, noting that “Honeywell held that ‘unexpected properties may cause what may appear to be an obvious composition to be nonobvious,’ not that unexpected mechanisms of action must be found to make the known use of known compounds nonobvious.” The court agreed with the Board that the recitation of various mechanistic steps in the claims was insufficient to overcome the prima facie obviousness of the claimed methods, observing that:

While mechanisms of action may not always meet the most rigid standards for inherency, they are still simply results that naturally flow from the administration of a given compound or mixture of compounds. Reciting the mechanism for known compounds to yield a known result cannot overcome a prima facie case of obviousness, even if the nature of that mechanism is unexpected.

. . .

To establish unexpected results, Couvaras would have needed to show that the co-administration of a GABA-a agonist and an ARB provided an unexpected benefit, such as, e.g., better control of hypertension, less toxicity to patients, or the ability to use surprisingly low dosages. We agree with the Board that no such benefits have been shown, and therefore no evidence of unexpected results exist.

Some Thoughts on Amgen v. Sanofi

By Chris Holman

Much has been already been written about the Supreme Court’s recent decision in Amgen v. Sanofi, including Dennis’s prompt response. Speaking for myself, I read Amgen as an endorsement of the Federal Circuit’s current interpretation and application of the enablement requirement, and maintenance of the status quo. The enablement requirement is an important (and I would argue the primary) non-prior art-based doctrinal tool for policing claim scope, and as such it plays an important role in preventing inventors of pioneering inventions from laying too much claim to subsequent innovation.

As the Supreme Court observed in Amgen, although Sawyer and Man might have been the first to invent an electric lamp filament of “carbonized fibrous or textile material,” this achievement did not necessarily entitle them to a patent encompassing all electric lamps filaments constructed of this broadly defined class of material, including Edison’s subsequent, but apparently vastly superior, bamboo-based filament. Similarly, Samuel Morse’s invention of the telegraph did not mean he was allowed a patent encompassing any use of electricity “for marking or printing intelligible characters, signs, or letters, at any distance” (sounds like the internet). And in the realm of biopharmaceuticals, the discovery of an antibody capable of specifically binding a particular epitope does not necessarily justify a patent claim encompassing all antibodies specific for that epitope, including antibodies having different (or even superior) pharmaceutical function, a point raised by Sanofi in its briefing of Amgen.

For years, this has been Federal Circuit’s interpretation of the enablement requirement, which requires the scope of the patent’s disclosure to be “commensurate” with the scope of the claims. In Amgen the Supreme Court essentially paraphrased this long-standing standard, stating that “we understand [the Federal Circuit] to have recognized only that the more a party claims for itself the more it must enable. [T]hat much is entirely consistent with Congress’s directive and this Court’s precedents.”

At the same time, it has also long been understood that a patentee is not required to literally enable a person of skill in the art to make and use every embodiment falling within the scope of a patent claim in order to satisfy the enablement requirement. For example, it is uncontroversial that a patent claim broadly directed towards pharmaceutical compositions comprising a specified active ingredient is not invalid for lack of enablement simply because the claim encompasses improved formulations of that active ingredient (e.g., timed release or combination products) that are not literally enabled by the original patent.  In many cases, such formulations are sufficiently innovative to justify their own patent, sometimes referred to as an “improvement patent.”  I do not think that anything in Amgen should be interpreted as altering this fundamental understanding of the enablement requirement.

Over the last few years I have written quite a bit about the enablement requirement, particularly in the context of therapeutic antibodies and other pharmaceuticals. For those who might be interested, here are some links to those articles, along with a brief description of some of the points raised in those articles.

I will begin with two articles I co-authored with Professor S. Sean Tu, entitled Antibody Patents: Use of the Written Description and Enablement Requirements at the Patent & Trademark Office and Antibody Claims and the Evolution of the Written Description / Enablement Requirement.  These articles report the results of an empirical study wherein we found that over the last couple of decades patent examiners faced with antibody claims have steadily increased the use of enablement and written description rejections, and have shifted from the issuance of broad, functionally-defined antibody claims (such as the claims struck down in Amgen) to narrower, structurally-defined claims (such as the sequence-based patent claims Amgen and Sanofi have obtained on their respective products, which the Federal Circuit and Supreme Court both pointed to with seeming approval).

In another article, Amgen v. Sanofi: The Supreme Court Takes up the Enablement Requirement in the Context of Therapeutic Monoclonal Antibodies, I offered some thoughts on Amgen prior to the Supreme Court deciding the case.   The article summarizes some of the main arguments that were raised in Amgen’s successful petition for certiorari, as well as Sanofi’s brief in opposition and a number of amici curiae briefs filed by various interested parties, including the U. S. government’s brief recommending that the Court not grant certiorari.

Amgen’s petition for certiorari relied heavily upon a 2020 law review article entitled The Death of the Genus Claim (“Death”), which purports to document a dramatic shift in the Federal Circuit’s interpretation of the enablement and written description requirements that has rendered it nearly impossible to obtain a chemical genus claim that will withstand judicial scrutiny.  Perhaps Death played some role in the Court’s decision to grant certiorari.  In any event, I responded to Death with my own two-part article, entitled Is the Chemical Genus Claim Really “Dead” at the Federal Circuit?, Parts I and II.

In Part I, I analyzed the judicial decisions upon which Death bases its claim, and explain why, in my view, the article does not substantiate its claim of a marked shift in the Federal Circuit’s interpretation and application of 112(a).  In Part II, I push back against one particular assertion made in Death, i.e., the suggestion that patentees can circumvent the Federal Circuit’s purported heightened application of 112(a) to chemical genus claims by drafting broader claims that define chemical genuses solely in structural terms, without the inclusion of any functional limitations. Part II then reviews a substantial number of judicial decisions involving chemical genus claims, and finds little evidence of a pronounced change in the application of 112(a) to chemical genus claims over the time span which Death identifies as corresponding to a purported dramatic shift in the law.

In another article, The Enablement and Written Description Requirements Through the Lens of the Federal Circuit’s Actions (As Opposed to Its Words), I observe that, when applying patent law’s enablement and written description requirements to police the scope of chemical genus claims, there can at times be a marked divergence between what the Federal Circuit says the law is and what the court actually does. For example, although the Federal Circuit has repeatedly stated that a patentee must enable the “full scope” of a patent claim in order to comply with 112(a), that is clearly not literally true – rarely if ever does a patent enable every conceivable embodiment that would fall within the scope of a patent claim, a task that would be impossible in most (if not all) cases, given the open-ended nature of most patent claims.  In Amgen, the Supreme Court expressly observed that “we review judgments of the lower courts, not statements in their opinions,” which I interpret as tacit recognition of the importance of focusing more on the actions of the Federal Circuit, as opposed to statements in the opinions that can sometimes be misleading when divorced from context.

Petitioner’s Failure to Argue that Prior Art was Analogous to Challenged Patent Results in Reversal of IPR Decision

By Chris Holman

Sanofi-Aventis Deutschland GMBH v. Mylan Pharms Inc., 2023 WL 3311549, — F.4th — (Fed. Cir. May 9, 2023).

The “analogous arts” test is used in patent law to determine whether a particular reference is relevant for the purposes of an obviousness analysis. Under this two prong test, a reference is relevant if it is from the same field of endeavor as the invention at issue, or if it is reasonably pertinent to the problem the invention is trying to solve.  In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004)

In its 2007 KSR v. Teleflex decision, the Supreme Court ruled that the obviousness analysis should be more flexible and not confined to rigid rules or tests. Rather, KSR emphasized an “expansive and flexible approach” to obviousness.  While KSR did not directly address the analogous arts test, it could be interpreted as calling for a more flexible approach allowing courts and the PTO more leeway to consider prior art from a broader range of sources as being “analogous” or “reasonably pertinent,” which in principle should make it easier for challengers to invalidate patents.

In inter partes review (IPR) proceedings, the Patent Trial and Appeal Board (PTAB) has invalidated patents claims for obviousness based on cited prior art that the PTAB found to be analogous, and until now the Federal Circuit has consistently affirmed those decisions on appeal.  Unwired Planet, LLC v. Google Inc., 841 F.3d 995 (Fed. Cir. 2016); Smartdoor Holdings, Inc. v. Edmit Indus., Inc., 707 F. App’x 705 (Fed. Cir. 2017); Toyota Motor Corp. v. Reactive Surfaces Ltd., LLP, 816 F. App’x 480 (Fed. Cir. 2020); CyWee Grp. Ltd. v. Google LLC, 847 F. App’x 910 (Fed. Cir. 2021); and Kamstrup A/S v. Axioma Metering UAB, 43 F.4th 1374 (Fed. Cir. 2022)).

On occasion, the PTAB has found cited prior art to be non-analogous, and thus irrelevant for purposes of the obviousness inquiry.  The Federal has twice affirmed those decisions on appeal.   Polygroup Ltd. MCO v. Willis Elec. Co., Ltd, 759 F. App’x 934 (Fed. Cir. 2019) and Broadcom Corp. v. Int’l Trade Comm’n, 28 F.4th 240 (Fed. Cir. 2022)).  In one reported decision, Donner Tech., LLC v. Pro Stage Gear, LLC, 979 F.3d 1353 (Fed. Cir. 2020), the Federal Circuit vacated and remanded after concluding that the Board had applied the wrong standard when it determined that a cited prior art reference was not analogous art.

On May 9, in Sanofi-Aventis Deutschland GmbH v. Mylan Pharms. Inc., the Federal Circuit held for the first time (to the best of my knowledge) that the PTAB erred in finding cited prior art to be analogous in an IPR.  Significantly, the Federal Circuit’s decision did not address the merits of the analogous art question, but instead was based entirely on the fact that the patent challenger (Mylan) had failed to allege that the cited prior art was analogous to the challenged patent (U.S. Patent No. RE47,614, which relates to pen injectors used for the delivery of drugs such as insulin).

The court observed that:

A petitioner is not required to anticipate and raise analogous art arguments in its petition; instead a petitioner can use its reply to “respond to arguments raised in the corresponding opposition, patent owner preliminary response, patent owner response, or decision on institution.” See 37 C.F.R. § 42.23. However, Mylan did not use its reply to explain how de Gennes is analogous to the ‘614 patent.

The court reversed the PTAB’s finding of nonobviousness because it had relied upon a finding that the de Gennes reference was analogous prior art, but Mylan had never made the required analogous art argument. Mylan argued on appeal that it had, in its IPR petition, effectively argued that the de Gennes reference was analogous to another other cited prior art reference, i.e., Burren, and that Burren and the challenged Sanofi patent address the “same problem.”  However, the court found Mylan’s arguments as to Burren insufficient to carry its burden because they did not directly address the challenged patent.

The court explained that:

In evaluating whether a reference is analogous, we have consistently held that a patent challenger must compare the reference to the challenged patent. This conclusion is reinforced by the purpose of the analogous art test, which is to examine whether a reference can be considered as prior art to the challenged patent in the first place. [The] purpose of the “prior art” must be evaluated with reference to the inventor’s purported invention disclosed within the challenged patent.


Amgen Scores Partial Victory in Efforts to Maintain OTEZLA Exclusivity

By Chris Holman

Amgen Inc. v. Sandoz Inc., 2023 WL 2994166, — 4th —   (Fed. Cir. Apr. 19, 2023)

In 2019, Amgen acquired worldwide rights to apremilast (OTEZLA) from Celgene $13.4 billion in cash, in connection with Celgene’s merger with Bristol-Myers Squibb. Apremilast was the only oral, non-biologic treatment for psoriasis and psoriatic arthritis, and in 2020 apremilast generated $2.2 billion for Amgen.

At the time Amgen’s acquired apremilast, Celgene was involved in Hatch-Waxman litigation with numerous generic challengers, including Sandoz. Celgene had asserted three of its 11 Orange Book-listed patents against Sandoz, and in 2020 Amgen was substituted as plaintiff.

The primary patent asserted is U. S. Patent 7,427,638, which is directed to pharmaceutical compositions comprising stereochemically pure apremilast. The original expiration date of this patent was in 2024, but the patent received a patent term extension of more than three years, resulting in an effective patent expiration date of February 16, 2028, according to the Orange Book.

Celgene also asserted U. S. Patent 7,893,101, which is directed to enantiomerically pure solid forms (e.g., crystalline polymorphic forms) of apremilast. This patent is due to expire December 9, 2023.

The third patent asserted by Celgene was U. S. Patent 10,092,541, directed to methods for treating a patient using dose titration of apremilast. According to the Orange Book, this patent was set to expire on May 29, 2034.

The district court found the claims of the ‘638 and ‘101 patents to be infringed and not invalid, and enjoined generic apremilast until the expiration of the ‘638 patent in February 2028. On appeal the Federal Circuit affirmed, an outcome that Amgen characterizes as a win.

On the other hand, the district court found the asserted claims of the ‘541 patent to be invalid for obviousness, which reportedly “pleased” Sandoz because the ruling “enables Sandoz to launch [its] generic apremilast product in the U. S. in 2028, six years prior to the expiry date of the latest-expiring Amgen patent asserted in litigation.”  On appeal, the Federal Circuit affirmed with respect to the obviousness of the ‘541 patent.

Here is a brief overview of the court’s decision regarding the asserted obviousness of these patents.

The ‘638 patent claims apremilast, which is the stereochemically pure (+) enantiomer of a compound falls that within a class of molecules referred to as phosphodiesterase-4 (“PDE4”) inhibitors.  Sandoz’s obviousness argument was based primarily upon a prior art Celgene patent, U. S. Patent 6,020,058, which includes an Example 12 that describes a racemic mixture containing apremilast, but that does not disclose the purified (+) enantiomer. The Federal Circuit found that the district court had not erred in holding that Sandoz had not proven that a skilled artisan would have had sufficient motivation to purify the (+) enantiomer from the racemic mixture disclosed in Example 12, nor that a skilled artisan would have had a reasonable expectation of success in resolving that mixture into its enantiomeric components, given the unpredictable nature of resolving racemic mixtures.

The Federal Circuit further found that the district court had not erred in its finding of strong objective indicia of nonobviousness, particularly given the unexpected potency of apremilast relative to the apremilast-containing racemic mixture disclosed in Example 12. The court credited testimony from a Celgene researcher listed as an inventor on the ‘638 patent, who noted a 20-fold difference in potency between apremilast alone and the racemic mixture, and stated that the inventors “didn’t expect a 20-fold difference in potency… Normally, if a racemate is a 50/50 mixture of two enantiomers, you might expect a two-fold difference in potency, all things being equal.” The district court also did not err in determining that apremilast satisfied a long felt need for an improved psoriasis treatment suitable for oral administration, that others in the field had tried and failed to develop other PDE4 inhibitors as drugs, and that there had been a degree of skepticism about the safety of apremilast because of its structural similarity to thalidomide, a drug notorious for its teratogenic effects in fetuses leading to severe and debilitating birth defects.

The issue with respect to the ‘101 patent was whether it could rely upon the filing date of a provisional application to which it claims priority. The ‘101 patent claims crystalline Form B of apremilast, and the provisional application includes an Example 2 which discloses a synthetic procedure for preparing apremilast. Although Example 2 does not explicitly disclose that the resulting apremilast has the Form B crystalline structure, Amgen provided the court with the results of over a dozen experiments following the procedure of Example 2, all of which resulted in crystalline Form B of apremilast, while Sandoz had provided no evidence to establish that Example 2 was capable of producing a crystalline Form other than Form B. Although the district court had based its holding on its conclusion that the provisional application inherently disclose crystalline Form B of apremilast, the Federal Circuit found that it did not need to reach the issue of inherent disclosure because the evidence established that Example 2 actually disclosed crystalline Form B of apremilast, albeit without specifically disclosing the crystal structure of the resulting product.

The ‘541 patent claimed a method of treating a patient with apremilast that basically involves starting with a relatively low dose and, over a course of days, gradually increasing the dosage to arrive at a full dosage which is significantly higher than the initial dosage, i.e., a dose-titration schedule. The court found this to be an obvious method, in view of prior art disclosing a similar dosage schedule. The Federal Circuit observed that, as a general matter, varying doses in response to the occurrence of side effects is well-known and obvious to the skilled artisan.

Overlapping Ranges in Claims and Prior Art Result in Invalidation of Patent on Transdermal Patch for Parkinson’s Disease

By Chris Holman

UCB, Inc. v. Actavis Lab’ys UT, Inc., 2023 WL 2904757, — 4th —   (Fed. Cir. Apr. 12, 2023)

Rotigotine is a drug used to treat Parkinson’s disease. People with Parkinson’s disease experience significant gastrointestinal dysfunction, such as difficulty swallowing, which can frustrate the oral administration of drugs. However, the complications associated with oral treatment can be avoided by means of a transdermal patch that delivers the drug through the patient’s skin.  In order to cross the skin barrier, however, the drug must be in an “amorphous,” i.e., non-crystalline, form.  If the drug crystallizes in the patch, it will generally not be able to cross the skin barrier.

In 2007, UCB invented and marketed “original Neupro,” a transdermal patch for the treatment of Parkinson’s disease containing a dispersion of amorphous rotigotine and polyvinylpyrrolidone (PVP), with the PVP functioning as a stabilizer. Unfortunately, soon after original Neupro entered the market it was found that the rotigotine was crystallizing when stored at room temperature, rendering the drug ineffective.  This caused UCB to recall the product from the U.S. market in April 2008 (although it remained in limited use under a compassionate-use program). In Europe, regulators allowed original Neupro to stay on the market, under the condition that it would only be marketed under “cold-chain conditions,” i.e., it would be stored in a refrigerator.

The patent at issue in this case, U.S. Patent No. 10,130,589, is directed towards UCB’s solution to this problem, which was to essentially double the amount of PVP in the patch, from original Neupro’s weight ratio of rotigotine to PVP of 9:2 to the new, reformulated Neupro’s weight ratio of 9:4. In particular the ‘589 patent claims a method for stabilizing rotigotine by combining a non-crystalline form of rotigotine with PVP to form a solid dispersion, wherein the weight ratio of rotigotine to PVP is in a range from about 9:4 to 9:6. UCB re-entered the U. S. market with its reformulated Neupro in 2012.

In 2019, UCB sued Actavis for infringing the ‘589 patent in a Hatch-Waxman lawsuit.  The district court found the asserted claims to be invalid based on anticipation and obviousness, particularly in view of earlier-issued UCB patents, i.e., the “Muller patents,” which disclosed combinations of rotigotine and PVP present at a range of weight ratios from 9:1.5 to 9.5. Note that the Muller patents cover both original Neupro (9:2) and reformulated Neupro (9:4), while the ‘589 patent (claiming a range of 9:4 to 9:6) only covers reformulated Neupro. Significantly, UCB had successfully asserted a Muller patent in a previous ANDA suit that resulted in an injunction preventing approval of Actavis’s ANDA until the relevant Muller patent’s expiration in March 2021. The ‘589 patent would not have expired until December 2030, and thus could have delayed FDA approval of a generic version of Neupro by nine additional years.

On appeal, the Federal Circuit reversed the district court’s anticipation ruling, but affirmed on the basis of obviousness. The opinion, authored by Judge Stoll, begins by explaining that Federal Circuit precedent sets forth an established framework for analyzing whether a prior art reference anticipates a claimed range. If the prior art discloses a point within the claimed range, the prior art anticipates the claim. On the other hand, if the prior art discloses an overlapping range, the prior art anticipates the claimed range “only if it describes the claimed range with sufficient specificity such that a reasonable factfinder could conclude there is no reasonable difference in how the inventions operate over the ranges.”

In the case at hand, the prior art Muller patents disclose a range (9:1.5 to 9.5) that overlaps with the range claimed in the ‘589 patent (9:4 to 9:6). The Federal Circuit found that the district court had erred by failing to analyze this as an overlapping range case, but to instead treat this as a case in which the prior art discloses a point within the claimed range.  The Muller patents did not literally disclose any point within the range claimed in the ‘589 patent, but the district court had nonetheless concluded, based on expert testimony, that the range disclosed in the Muller patents would implicitly teach a person of skill “a few examples” of specific weight ratios, including 9:4 and 9:5 weight ratios of rotigotine to PVP. Nonetheless, the district court’s error with regard to its anticipation analysis was rendered moot when the Federal Circuit proceeded to affirm its obviousness finding.

Judge Stoll cited Federal Circuit precedent for the proposition that there is a presumption of obviousness when a claimed range overlaps with a range disclosed in the prior art. Although this presumption can be overcome if, e.g., the prior art teaches away from the claimed range, or the claimed range produces new and unexpected results, or other evidence demonstrates the nonobviousness of the claimed range, in this case the Federal Circuit agreed with the district court that UCB had failed to present evidence to rebut the presumption of obviousness.

For example, the district court had not erred in its decision to disregard the commercial success of reformulated Neupro, based on a lack of a nexus between the drug’s commercial success and the claimed invention. In particular, the Federal Circuit agreed that the existence of the Muller patents weakened UCB’s evidence of commercial success, because these patents operated as blocking patents, dissuading competitors from developing a rotigotine transdermal patch, at least until the Muller patents expired. While rejecting UCB’s suggestion that the court’s analysis had branded all co-owned patents as “blocking” patents, the court noted that in this case UCB had held exclusive worldwide rights to rotigotine for all therapeutic indications since 1998, and that until the Muller patents expired Actavis had been enjoined from marketing a generic version of reformulated Neupro.

Multiple dependent claims, blaze marks, and ipsis verbis support

By Chris Holman

University of Minnesota v. Gilead

This is a follow-up to Dennis’s post discussing a recent Federal Circuit decision, University of Minnesota v. Gilead, wherein the university was essentially precluded from claiming priority to a provisional patent application because the provisional failed to provide adequate written description support for a later claimed invention.

Note that a provisional patent application is not required to include any patent claims, since a provisional can never mature into an actual patent, but only serves to provide an earlier effective filing date for a later-filed non-provisional patent application, assuming certain requirements are satisfied. In this case, however, the university’s provisional application included 63 claims, 49 of which are directed toward “[a] compound of Formula I:

wherein: . . . .”

The bodies of the claims defines various possible substituents at the seven “R” positions.  Here are the claims filed in the provisional application.

Claim 1 is the only independent claim, defining a genus of astronomical proportions. As Judge Lourie puts it, “the listings of possibilities are so long, and so interwoven, that it is quite unclear how many compounds actually fall within the described genera and subgenera.”  Claim 49 is the only claim that recites a single chemical “species,” presumably the molecule that the university thought was the most promising at the time the provisional was drafted.

Claims 2-48 lie between these two extremes, defining a huge number of subgenuses of the genus of compounds defined by Claim 1 – by my count over 500,000. (Note that the terms genus, subgenus, and species are relative terms when used in this context.)  How, one might ask, can 47 patent claims define over half a million subgenuses? The answer is through the use of multiple dependent claims that depend upon other multiple dependent claims, a practice that is not permitted under U. S. law.

The Manual of Patent Examiner Procedure (MPEP) defines a multiple dependent claim as “a dependent claim which refers back in the alternative to more than one preceding independent or dependent claim.”  It also cites 37 C.F.R. 1.75 for the proposition that “[a] multiple dependent claim shall not serve as a basis for any other multiple dependent claim.”

37 C.F.R. 1.75 further provides that for fee calculation purposes, a multiple dependent claim will be considered to be that number of claims to which direct reference is made therein. For fee calculation purposes also, any claim depending from a multiple dependent claim will be considered to be that number of claims to which direct reference is made in that multiple dependent claim.

This fee calculation policy reflects the reality that a multiple dependent claim is simply a shorthand means of reciting multiple discrete patent claims.  For example, the provisional’s claim 12 recites “[t]he compound of any one of claims 1-11 wherein R2 is hydroxy.”  That is simply shorthand for and the functional equivalent of 11 discrete dependent claims, i.e., the compound of claim 1 wherein R2 is hydroxy, the compound of claim 2 wherein R2 is hydroxy, the compound of claim 3 wherein R2 is hydroxy, the compound of claim 4 wherein R2 is hydroxy, etc..

When you start going down the path of multiple dependent claims that depend upon other multiple dependent claims, which in turn depend on other multiple dependent claims, etc., the number of discrete dependent claims can become immense. In this case, the provisional’s claim 47 is a multiple dependent claim that, inter alia, refers back to another multiple dependent claim (claim 45), which in turn refers back to a third multiple dependent claim (claim 33), which refers back to a fourth multiple dependent claim (claim 21), which refers back to a fifth multiple dependent claim (claim 13), which refers back to dependent claim 2. If you follow this path, you arrive at a subgenus that the University asserts is the same subgenus claimed in the later issued patent.  Assuming this to be correct, then, as Dennis pointed out in his post, claim 47 does appear to encompass a claim that specifically defines the later claimed subgenus.

The problem is, claim 47 also encompasses 250,880 other unique claims, each of which defines its own subgenus. The huge number results from the multiplicative effect of five iterations of multiple dependent claims. One can readily understand why the PTO does not allow multiple dependent claims that depend on other multiple dependent claims. But since this was only a provisional application, the claims were never examined, and are simply serving as a vehicle for disclosing a huge number of subgenuses.  By my count, the provisional includes a total of 584,431 subgenus claims.

The Board concluded that the claims in the provisional did not provide ipsis verbis support for the later claimed subgenus, albeit without providing much in the way of explanation, and the Federal Circuit affirmed. Black’s Law dictionary defines ipsis verbis as “in the identical words, as opposed to substantially.” In my view, claim 47 does literally describe the later claimed subgenus, the problem is that it is buried in astronomical number of other subgenuses.

The courts have long used the terminology of “blaze marks” when assessing written description support for a later claimed chemical compound or genus.  The term refers to the practice of marking a trail through the forest by slashing the bark of trees. Expanding upon that metaphor, imagine a vast forest wherein there lies hidden a beautiful waterfall.  One could employ blaze marks to chart out a trail leading to the waterfall.  But if all of the trees in the forest have a blaze mark, the explorer would have no idea which marks to follow, regardless of the fact that one could go back retrospectively and point out specific blaze marks that would define a trail leading to the waterfall.  The point is, even if there are blaze marks defining a trail to the waterfall, as a practical matter it would be very difficult to find the correct trail if there are too many other blaze marks defining a huge number of trails that do not lead to the waterfall.

Returning to the case at hand, I do not think the result would have changed if somehow the university could have, perhaps with the help of AI, drafted 584,331 discrete dependent claims that would have been the functional equivalent of the multiple dependent claims that it did file in its provisional application.  At some point, the disclosure of too many alternative possibilities can, as a practical matter, negate the disclosure of one specific subgenus. I would suggest that this is the basis for the Board’s determination that there was not ipsis verbis support for the later claimed subgenus, nor were there sufficient blaze marks pointing the way.

And given the standard of review, it is not surprising to me that the Federal Circuit affirmed.  As stated in its opinion, “the primary considerations in a written description analysis are factual and must be assessed on a case-by-case basis. We thus review the Board’s decision regarding written description for substantial evidence.”

Federal Circuit Gives Stare Decisis Effect to a Judgment of Claim Validity

by Chris Holman

C.R. Bard, Inc. v. Med. Components, Inc., 2023 WL 2064163 (Fed. Cir. Feb. 17, 2023)

In Blonder-Tongue Laboratories, Inc. v. University of Illinois Foundation (1971), the Supreme Court held that a judgment of invalidity in a suit against one infringer accrues to the benefit of any other accused infringer unless the patent owner shows that he did not have a fair opportunity procedurally, substantively and evidentially to pursue his patent claim the first time.  Collateral estoppel (i.e., issue preclusion) under Blonder-Tongue is non-mutual.  While a judgment of invalidity binds the patent owner and its successors in interest because it is a party to the suit with adequate opportunity to contest the matter, a judgment of validity cannot operate in the patent owner’s favor to bind persons who are neither parties nor in privity with parties to the suit.

Stare decisis,  Latin for “to stand by things decided,” is a legal principle that directs courts to adhere to previous judgments, i.e., precedent, when resolving a case with comparable facts.  According to Chisum on Patents, “Federal Circuit decisions decline to give great weight or stare decisis effect to prior validity rulings.”  For example, in Gillette Co. v. S.C. Johnson & Son, Inc., (1990), the court held that the fact that the validity of a patent claim has previously been upheld in an earlier litigation is not to be given  stare decisis effect, citing Stevenson v. Sears, Roebuck & Co. (Fed. Cir. 1983).

In a recent non-precedential opinion, C.R. Bard, Inc. v. Med. Components, Inc., the Federal Circuit applied stare decisis to a prior validity ruling involving a different patent and a different accused infringer.  The Bard patents at issue are directed to radiopaque markings and structural features that can be used to identify whether a venous access port is power injectable, specifically a venous access port with an alphanumeric message that can be seen on an X-ray and that identifies the port as power injectable.

Representative claim 5 of U.S. Patent No. 7,785,302 claims:

A venous access port assembly for implantation into a patient, comprising:

a housing having an outlet, and a needle-penetrable septum, the needle penetrable septum and the housing together defining a reservoir, wherein:

the assembly includes a radiopaque alphanumeric message observable through interaction with X-rays subsequent to subcutaneous implantation of the assembly, and

the alphanumeric message indicating that the assembly is power injectable.

On motion for summary judgment, the district court found the asserted claims ineligible under § 101 because the claims were solely directed to non-functional printed matter and because the claims were directed to the abstract idea of “[using] an identifier to communicate information about the power injectability of the underlying port” with no inventive concept.

On appeal, the Federal Circuit reversed, explaining:

We are bound by our precedent in C R Bard Inc. v. AngioDynamics, Inc., 979 F.3d 1372 (Fed. Cir. 2020). There, we considered a case that is virtually identical to the one before us now. AngioDynamics also involved patents directed to radiopaque markers that could be used to identify venous access ports as power injectable, and the claims at issue were substantially similar to the asserted claims here. Furthermore, that case asked to consider the exact same question that is before us now: whether claims that include non-functional printed matter could be eligible under § 101. The court in AngioDynamics concluded that, although the asserted claims contained some non-functional printed matter, they were nonetheless eligible under § 101 because the claims were not solely directed to non-functional printed matter—they were also directed to “the means by which that information is conveyed.” Given these similarities, we must reach the same conclusion here as in AngioDynamics.

Because we are bound by our precedent, we conclude that the asserted claims in Bard’s three patents are directed to eligible subject matter under § 101.

As noted above, Chisum’s authoritative treatise on U. S. patent law states that the Federal Circuit does not give “great weight or stare decisis effect to prior validity rulings,” and does not identify any cases which this has occurred.  The C.R. Bard court does not cite to any precedent, case law, or statute to justify its application of stare decisis in the present case.

Perhaps patent eligibility is uniquely amenable to stare decisis, given the amorphous nature of the Alice two part inquiry.  In its opening brief, Bard argued that:

Despite acknowledging the obvious similarities between AngioDynamics and the instant case, the district court . . .  declined to follow it because “the facts and procedural posture are different.” But in AngioDynamics, this Court held that Bard’s patents were valid at Alice step one. Because Alice step one presents a legal question that can be answered based on the intrinsic evidence, CardioNet, LLC v. InfoBionic, Inc., 955 F.3d 1358, 1372 (Fed. Cir. 2020), any supposed differences in the record are irrelevant and thus provide no basis to depart from this Court’s holding that claims directed to features on ports for the purposes of post-implantation identification traverse Alice step one.

AngioDynamics (the company that lost on the issue of patent eligibility in the AngioDynamics decision) filed an amicus brief in C.R. Bard in support of the accused infringer, urging affirmance of the district court’s decision finding the claims patent ineligible. The company argued that the AngioDynamics decision addressed a different factual record and different legal issues, and that:

Unlike the district court in AngioDynamics, the district court here performed a full two-step Alice analysis. The district court also considered a significantly more developed record than the one in AngioDynamics, including multiple prior art references, Bard’s admissions that it did not invent radiopaque identifiers, and Bard’s admissions that adding radiopaque identifiers to ports would be trivial. . . . Bard’s reliance on AngioDynamics is misplaced.

AngioDynamics states in its amicus brief that its interest in the case stems from its involvement in litigation related to the patents asserted in C.R. Bard, as well as other Bard patents directed to “nearly identical subject matter,” which it believes would be impacted by Bard’s appeal. Presumably, the company was hoping to benefit from the collateral estoppel effect of the district court’s patent ineligibility ruling.

Genentech v. Sandoz: Patents claiming methods of managing side effects found invalid or not infringed

by Chris Holman

A branded drug manufacturer can sometimes extend its exclusive right to market a drug by patenting a method of using the drug and successfully suing a potential generic competitor for infringement based on the premise that an instruction or warning appearing on the generic product’s label will induce doctors and/or patients to infringe the patent. In some cases, a generic company can skirt infringement by means of a “skinny label” that carves out the patented method, a practice that is the subject of a pending petition for certiorari in Teva v. GSK, as discussed by Dennis in a recent post (see an earlier post for a more detailed discussion of Teva and skinny labels).

In Teva, the drug is approved for the treatment of multiple indications, two of which are unpatented, and the generic company attempted to avoid infringement by carving out (unsuccessfully, absent Supreme Court intervention) an indication covered by the patent.  In a case in which a patent covers a method of using the drug safely, as opposed to a new indication, the skinny label option is generally not available, and the generic product label will be required to closely track the label of the branded product. A remaining option for a generic company facing such a patent is to challenge it in a Hatch-Waxman proceeding and successfully argue that the patent claims are invalid and/or not infringed. An example of this appears in the Federal Circuit’s recent decision in Genentech v. Sandoz.

The active ingredient at issue in Genentech is pirfenidone, marketed by Genentech under the tradename ESBRIET.  Pirfenidone was first studied as an investigational new drug in 1973.   In 2004, the United States Food and Drug Administration (“FDA”) granted pirfenidone orphan drug status for treatment of patients with idiopathic pulmonary fibrosis (“IPF”), a chronic, irreversible lung disease.  In 2008 it was approved for the treatment of IPF in Japan under the trade name of PIRESPA.  Approvals in the European Union and Canada followed in 2011 and 2012, respectively.

When Genentech obtained approval to market pirfenidone (ESBRIET) in the U.S. in 2014, it was granted seven years of orphan drug exclusivity, which expired in 2021.  However, Genentech still holds 19 Orange Book-listed patents purportedly covering ESBRIET. The patents were issued between 2009 and 2014, and expire between 2026 and 2033.

Sandoz submitted Abbreviated New Drug Applications (“ANDAs”) seeking approval from the FDA to market a generic version of pirfenidone, to which Genentech responded by bringing a Hatch-Waxman suit, asserting that Sandoz’s generic product would induce the infringement of five of the Orange Book-listed patents.  The asserted patents do not claim pirfenidone itself, or the use of pirfenidone to treat IPF. Instead, the patents claim methods for managing certain side effects that can occur when using pirfenidone to treat IPF. The patents fall into two categories: the Liver Function Test (“LFT”) patents and the Drug-Drug Interaction (“DDI”) patents.

The LFT patents are directed to methods for administering pirfenidone to a patient who has exhibited abnormal biomarkers of liver function in response to pirfenidone administration. The asserted claims in these patents recite various options, including: (1) temporarily reducing the dose of pirfenidone and then returning to the full dose, (2) maintaining the full dose of pirfenidone, (3) reducing the dose of pirfenidone, (4) discontinuing pirfenidone for a week and then returning to the full dose, and (5) discontinuing pirfenidone for a week and then returning to a reduced dose.

The DDI patents are directed to methods for avoiding adverse interactions between pirfenidone and fluvoxamine, a drug that can interfere with drug metabolism. The three asserted DDI claims involve methods for administering pirfenidone to a patient taking fluvoxamine by either discontinuing fluvoxamine or modifying the dose of pirfenidone and continuing fluvoxamine.

The district court found the LFT patents invalid for obviousness over a 2005 publication reporting the results of clinicals trials involving the use of pirfenidone in patients with IPF (the “Azuma” reference), combined with the PIRESPA label and “known, standard medical practices.”  Prior to reviewing the district court’s analysis, the Federal Circuit noted its:

initial perception that, as the district court noted, varying doses in response to the occurrence of side effects would seem to be a well-established, hence obvious, practice. Thus, claiming it as an invention would appear to be at best a long shot. The district court gave it careful scrutiny, however, as do we.

The Federal Circuit then proceeded to affirm the district court’s obviousness determination, stating that:

The asserted claims in the LFT patents do not represent the invention of a new drug, nor do they recite a novel application of an existing drug. Instead, these claims recite adjusting doses in the presence of side effects, which clinicians routinely do, and which would have been obvious in view of the prior art.

As to the DDI patents, the district court found that although warnings appearing on Sandoz’s proposed label appeared to encourage, recommend, and/or promotes infringement of the patents, there was insufficient evidence of direct infringement. The district court stated that:

Genentech had not shown that any patient would be prescribed both pirfenidone and fluvoxamine such that the methods of the DDI patents would even be relevant. [E]ven if an IPF patient were prescribed fluvoxamine, a physician would likely choose a non-infringing treatment adjustment over any of the claimed methods.

The Federal Circuit affirmed, noting that the evidence of record included testimony from physicians that, in their decades of treating IPF patients, they had never prescribed pirfenidone to an IPF patient taking fluvoxamine; and were they to find themselves in that position, they would choose a noninfringing response—i.e., prescribing nintedanib instead (nintedanib is another drug approved by FDA for the treatment of IPF).

Genentech argued that if an IPF patient needed fluvoxamine, instead of a doctor prescribing nintedanib to treat their IPF, the doctor could prescribe pirfenidone and an alternative to fluvoxamine. However, the court credited Sandoz’s expert testimony to the effect that:

a pulmonologist prescribing pirfenidone would not be able to alter another physician’s prescription of fluvoxamine or take over that aspect of the patient’s treatment. Therefore, the pulmonologist would prescribe nintedanib to be taken in conjunction with the patient’s preexisting prescription of fluvoxamine.

This was a split decision, with Judge Newman dissenting without offering an opinion.

After Granting Certiorari In Enablement Case, Supreme Court Declines Opportunity To Address Written Description

by Chris Holman

As reported in posts by Dennis and Jason, the Supreme Court recently granted certiorari in Amgen v. Sanofi, marking the first time that the Court has taken up patent law’s enablement requirement since enactment of the Patent Act of 1952. The claims at issue are directed to a genus of functionally-defined molecules having therapeutic utility, i.e., monoclonal antibodies defined in terms of binding specificity. For the sake of brevity, I will refer to claims of this type as “chemical genus claims.”

A few days later, on November 7, the Supreme Court denied certiorari in Juno v. Kite, a case challenging the Federal Circuit’s interpretation of the written description requirement. The claims struck down for lack of adequate written description in Juno are strikingly similar to the claims that were invalidated under the enablement requirement in Amgen, being directed towards nucleic acids encoding chimeric T cell receptors (for use in Car T-cell therapy), comprising, inter alia, a functionally defined “binding element,” as exemplified by a single-chain antibody variable fragment (‘‘scFv’’).

The scope afforded to chemical genus claims under 35 USC § 112(a)’s enablement and written description requirements has been hot topic recently (at least in certain quarters). Professors Lemley, Seymore, and Karshtedt (it is so sad that he is no longer with us) published an article in 2020 entitled The Death of the Genus Claim, which asserts that “the law has changed dramatically in the last thirty years, to the point where it is nearly impossible to maintain a valid genus claim.” Amgen’s successful petition for certiorari relies heavily on Death, and its authors filed an amici curiae brief in support of Amgen’s petition.

While Death clearly raises some valid concerns regarding the challenges inventors face in trying to secure effective patent scope for inventions of this type, in my view it is an overstatement to say that chemical genus claims are “dead.” I responded to Death in a two-part article arguing, for example, that the case law identified in Death provides scant support for its assertion that the standard for compliance with the enablement and written description requirements has become significantly more stringent in recent years. Christopher M. Holman, Is the Chemical Genus Claim Really “Dead” at the Federal Circuit?: Part II, 41 Biotechnology Law Report 58 (2022); Christopher M. Holman, Is the Chemical Genus Claim Really “Dead” at the Federal Circuit?: Part I, 41 Biotechnology Law Report 4 (2022).

I also point out that relatively broad chemical genus claims continue to survive § 112(a) challenges in the district courts and at the Federal Circuit.  See, for example, Ajinomoto Co. v. Int’l Trade Comm’n, 932 F.3d 1342 (Fed. Cir. 2019); Bayer Healthcare LLC v. Baxalta Inc., 989 F.3d 964 (Fed. Cir. 2021); Plexxikon Inc. v. Novartis Pharmaceuticals Corp., Case No. 17-cv-04405-HSG, Document 565, July 22,2021 (N.D. Cal.).

Section 112(a)’s enablement and written description requirements, sometimes referred to as the “adequate disclosure requirements,” constitute U. S. patent law’s primary non-prior art-based limitations on claim scope. Although Supreme Court has in the past indicated that it views the patent eligibility doctrine as playing an important role in preventing patent claims from broadly “preempting” abstract ideas and natural phenomena, more recently the Court’s patent eligibility decisions have focused on the sufficiency of “inventive concept,” as opposed to claim breadth per se.  Absent such limitations, under a regime in which claim scope would only be limited by the prior art, an inventor could potentially secure patent claims encompassing huge swaths of yet-to-be invented technologies.

Hypothetically, for example, the inventor of the first practical method for communicating at a distance using electricity, e.g., the telegraph, might have ended up with a patent claim encompassing all means of communicating at a distance using electricity, e.g., the internet. The inventor of a rudimentary, barely functional electric light bulb could, assuming it was the first lightbulb, potentially have obtained a patent claim encompassing all lightbulbs, including far superior lightbulbs produced by subsequent inventors. While I have simplified the facts quite a bit, the gist of these examples have been the subject of actual Supreme Court decisions. O’Reilly v. Morse and Consol. Elec. Light Co. v. McKeesport Light Co..  Not surprisingly, in both cases the Supreme Court struck down the patent claims as overly broad, invoking what we would today refer to as the enablement requirement.

More pertinent to the facts of Amgen v. Sanofi, the inventor of the first antibody capable of recognizing a particular antigen could potentially obtain a patent encompassing all antibodies capable of recognizing that antigen. For example, an inventor who has succeeded in producing a mouse monoclonal antibody that binds to a particular human protein (useless as a human therapeutic) could in principle obtain a patent claim encompassing all monoclonal antibodies that bind to that particular human protein, even a fully humanized antibody that functions as a safe and effective biologic drug, e.g., AbbVie’s blockbuster Humira, or the accused product in Amgen, Praluent.  Again, the gist of this example comes from an actual Federal Circuit decision, Noelle v. Lederman, wherein the claims at issue were struck down under the written description requirement.

The Federal Circuit has invoked both the written description and enablement requirements as doctrinal tools for policing claim scope. Although as a formal matter the written description requirement focuses on whether the inventor has demonstrated “possession” of the full scope of the claim, while the enablement requirement asks whether the scope of the claim is “commensurate” with the scope of disclosure, as a practical matter the two requirements have been applied in a manner that is largely redundant, albeit with a few distinctions of arguable significance discussed later in this post. In my article responding to Death, for example, I point out that the Ariad factors that the Federal Circuit has identified as relevant to assessing compliance with the written description requirement are, in substance, virtually identical to the Wands factors used in the enablement inquiry. If anything, the written description requirement has been seen as the more stringent of the two, particularly in the context of biotechnology – the written description requirement has often been referred to as a  “super-enablement” requirement.

And in fact, prior to Amgen, the Federal Circuit has tended to invoke the written description requirement, rather than the enablement requirement, in striking down monoclonal antibody genus claims. See, for example, Noelle v. Lederman, 355 F.3d 1343, 1349 (Fed. Cir. 2004)(disclosure of mouse monoclonal antibody specific for mouse antigen (CD40CR) did not provide adequate written description for claim encompassing any monoclonal antibody capable of binding the human analog of the CD40CR antigen); Centocor Ortho Biotech v. Abbott Laboratories, 636 F.3d 1341(Fed. Cir. 2011)(disclosure of previously characterized antigen (human TNF-alpha) and mouse antibodies to the antigen did not provide adequate written description for claim encompassing fully human monoclonal antibodies capable of binding to a specific neutralizing epitope of the antigen); AbbVie Deutschland GmbH & Co., KG v. Janssen Biotech, Inc., 759 F.3d 1285 (Fed. Cir. 2014)(disclosure of about 300 antibodies falling within the scope of the claim did not provide adequate written description for a claim reciting neutralizing human antibodies capable of specifically binding human interleukin-12 (IL-12)).

Of course, given the redundancy of the doctrines, a claim struck down as overly broad for lack of enablement is highly likely to be invalid for lack of adequate written description, and vice versa. In Amgen, for example, the jury found Amgen’s claims not invalid under the enablement and written description requirements, but on a motion for JMOL the district court overruled the jury and found that, as a matter of law, the claims are invalid under both the enablement and written description requirements. In Amgen, the Federal Circuit decided the issue based on a failure to comply with the written description requirement, rendering the enablement issue moot, but in the past the Federal Circuit has been more inclined to find claims of this type invalid for failure to comply with the written description requirement.  See the examples provided above, as well as the Juno decision.

Thus, one of the big elephants in the room with respect to the grant of certiorari in Amgen is that the question for review appears to focus solely on the enablement requirement. Even if the Supreme Court lowers the bar for compliance with the enablement requirement, the ruling would presumably have no direct impact on the written description requirement, which has conventionally been thought of as imposing an even higher bar for the sort of claim at issue in the case, e.g., functionally defined chemical genus claims.

Sanofi raised this point in its Opposition brief, arguing that any ruling by the Supreme Court would not be dispositive of the case because, if the Supreme Court overturns the enablement verdict, the Federal Circuit would likely still find the claims invalid for lack of adequate written description. Sanofi points out that Amgen’s own amici, i.e., Professors Lemley, Seymore and Karstedt, concluded in Death that the Federal Circuit had “strongly suggested” that the claims were not only invalid under the enablement requirement, but also the written description requirement.

Indeed, the Federal Circuit has on occasion explicitly noted that a claim’s compliance with the written description and enablement requirements generally rise and fall together. For example, in Idenix v. Gilead, a recent case involving claims analogous to those at issue in Amgen, the jury also found the claims to be not invalid under the enablement and written description requirements. The district court overturned the jury verdict with respect to enablement, but denied a motion for JMOL with respect to written description. On appeal, the Federal Circuit affirmed the district court’s holding that the claims were invalid for lack of enablement, but reversed its denial of JMOL for failure to meet the written description requirement, finding the claims invalid under both doctrines.

Under the Federal Circuit’s current interpretation of the written description and enablement requirements, I think it would be highly unusual for the court to find claims of the type at issue in Amgen invalid for lack of enablement but not for lack of adequate written description. In fact, when the district court decision in Idenix v. Gilead initially came out, finding the claims invalid under the enablement requirement but not under the written description requirement, I thought it was so striking that I wrote an article about it.   Christopher M. Holman, Enablement Invoked as a ‘‘Super-Written Description Requirement’’ to Overturn $2.5 Billion Jury Verdict, 37 Biotechnology Law Report 63 (2018). So I was not at all surprised when the Federal Circuit reversed and explicitly found the claims invalid under both the enablement and written description requirements, even though the Federal Circuit could have chosen not to address the written description issue as moot in light of the enablement ruling, as it did in Amgen.

In retrospect, I wonder if it might have been better for the Supreme Court to take up the issue of adequate disclosure in a case like Idenix, where the Federal Circuit explicitly addressed both the enablement and written description requirements in the context of the same chemical genus claims. As Jason intimated in his blog post, while it is relatively easy to point out the shortcomings in the Federal Circuit’s current § 112(a) jurisprudence, it is much harder to come up with an effective alternative. I have to think that it will be particularly difficult for the Supreme Court to make a positive contribution to the law of adequate disclosure without also taking into account the written description requirement.

Although the written description requirement has long been used to police the claiming of new matter, it only took on the role of policing claim scope as what is in essence an alternate enablement requirement in 1997 when the Federal Circuit decided UC Regents v. Eli Lily, creating what I refer to as the “Lilly written description requirement” (so as to distinguish it from the “traditional written description requirement” used prevent the claiming of new matter). Early on, the Lilly written description requirement seemed to impose a much higher threshold than enablement, particular for biotechnology inventions, hence its characterization as a “super-enablement requirement.” But it seems to me that at this point in time the standards for compliance with the written description and enablement requirements have become for the most part indistinguishable, as illustrated by the redundancy of the Ariad and Wands factors, and the paucity (or, to my knowledge, the absence) of any judicial decisions (upheld on appeal) explicitly finding a claim invalid under the Lilly written description requirement but not invalid for lack of enablement, or vice versa.

Nonetheless, Federal Circuit precedent has carved out some clear differences between the written description requirement and enablement, although as a practical matter it is not clear to me how significant those differences are.  For example, the Federal Circuit treats the written description requirement as a question of fact, and the enablement requirement as a question of law based on underlying factual findings.  In its petition for certiorari, Amgen also asked the Court to rule that enablement, like written description, is a question of fact, but the Court declined to take up that question. In principle, a decision by a jury (or judge in a bench trial) should be afforded more deference with respect to a question of fact, which might explain why in Amgen and Idenix the district courts overturned the juries’ enablement decisions, but not their written description decisions. However, it seems to me that when case reaches the Federal Circuit the formal distinction between question of fact and “question of law based on underlying factual findings” has little practical effect.  See, for example, Centocor Ortho Biotech v. Abbott Laboratories, 636 F.3d 1341(Fed. Cir. 2011)(overturning jury decision finding claim encompassing fully human monoclonal antibodies not invalid for failure to comply with the written description requirement).

Another difference between the two doctrines has to do with the admissibility of evidence.  In the Federal Circuit’s first decision in Amgen v. Sanofi (the grant of certiorari is with respect to the Federal Circuit second decision in the case), the court held that the district court had committed legal error by improperly excluding post-priority date evidence of antibodies falling within the scope of the claim, including the accused product (Praluent). The district court based its decision to exclude the evidence on a 1977 decision of the Court of Customs and Patent Appeals, In re Hogan, which the Federal Circuit has interpreted as prohibiting, in the context of the enablement inquiry, admission of “post-priority-date evidence proffered to illuminate the post-priority-date state of the art.”  Without questioning the continuing vitality of Hogan, the Federal Circuit held that, in the context of the written description inquiry, post-priority-date evidence is admissible to show that a patent fails to disclose a representative number of species, explaining that Hogan is silent with respect to evidence of this type. Thus, it seems that under some circumstances post-priority-date evidence illustrating the structural and functional breadth of a chemical genus claim could be admissible for purposes of a written description challenge but not a challenge for lack of enablement.

When Does Disclosure of a Chemical Genus Anticipate a Species?

by Chris Holman

Mylan Pharms. Inc. v. Merck Sharp & Dohme Corp., 2022 WL 4541687 (Fed. Cir. Sept. 29, 2022)

As a general rule of thumb, the prior art disclosure of a chemical species anticipates (and thus renders unpatentable) a chemical genus encompassing that species. The prior art disclosure of a chemical genus, on the other hand, generally does not anticipate a species falling within the scope of the genus – except when it does.  In re Petering, 301 F.2d 681 (C.C.P.A. 1962), decided by the Court of Customs and Patent Appeals (the predecessor of the Federal Circuit) in 1962, provides an example in which the court holds that prior art disclosing a genus of 20 chemical compounds anticipated a species falling within that genus. The Petering court explained that the prior art may be deemed to disclose each member of a genus when, reading the reference, a person of ordinary skill can “at once envisage each member of this limited class.”

Mylan v. Merck provides an example going the other way, with the Federal Circuit affirming a Patent Trial and Appeal Board decision finding that the prior art disclosure of a genus comprising 957 predicted salts did not anticipate the following claim, which recites one of those salts.

  1. A dihydrogenphosphate salt of a 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro [1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine of Formula I:

or a hydrate thereof.

The claimed salt is sitagliptin dihydrogenphosphate (“sitagliptin DHP”), a dipeptidyl peptidase-IV (“DP-IV”) inhibitor and the active ingredient in JANUVIA, which is marketed by Merck for the treatment of non-insulin-dependent (i.e., Type 2) diabetes.  Mylan petitioned for inter partes review (IPR) of a number of patent claims of U.S. Patent 7,326,708 (the “’708 patent”), including the independent claim presented above, as part of its bid to bring a generic version of JANUVIA to market prior to expiration of the patent. Mylan argued that the challenged claims were anticipated and/or rendered obvious by the disclosure of the genus of 957 salts in an earlier Merck-owned U.S. patent and its equivalent International Patent Publication (referred to collectively as “Edmondson”).

In particular, Mylan argued that under In re Petering Edmondson’s disclosure of the genus anticipated the challenged claims because a skilled artisan reading Edmondson would “at once envisage” the sitagliptin DHP salt. But the Board rejected this argument, finding that none of the challenged claims were anticipated by Edmondson. The Federal Circuit affirmed, finding that while In re Petering does stand for the proposition that a skilled artisan may “at once envisage each member of [a] limited class,” the “key term” in this statement is the word “limited.”  The court found that the genus of 957 salts disclosed in Edmondson is a far cry from the 20 compounds “envisaged” by the narrow genus in Petering.

The Federal Circuit went on to explain:

We cannot provide a specific number defining a “limited class.” It depends on the “class.” But we agree with Merck and hold that the Board did not err in finding that a class of 957 predicted salts[, as disclosed in Edmondson,] is insufficient to meet the “at once envisage” standard set forth in Petering.

The manner in which Edmondson discloses the genus probably had some bearing on the outcome. Edmondson does not explicitly define a genus of 957 salts. Instead, Edmondson discloses a list of 33 compounds, one of which was sitagliptin.  It also discloses eight “preferred salts,” one of which was phosphate, the salt used in sitagliptin DHP.  The product of multiplying 33 x 8 is 264, so there are at least 264 possible combinations of the 33 chemical compounds with the eight salts. But there are also possible differences in stoichiometry, i.e., the ratio of the salt’s ions. For example, the stoichiometry of the claimed sitagliptin DHP is 1:1, i.e., a 1-to-1 ratio of sitagliptin to phosphate.  However, other stoichiometry’s are possible.  For example, Merck was also able to prepare sitagliptin phosphates having stoichiometries of 3:2 and 2:1. Taking into account the various possible stoichiometries, the court accepted Merck’s representation that the 33 compounds could potentially be formulated into a total of 957 different salt forms using the eight preferred salts.

Of course, the fact that Edmondson does not anticipate the claims does not necessarily mean that it would not render them obvious, particularly in combination with other prior art references. In this case, however, Edmondson could not be used as a prior art reference for purposes of obviousness with respect to a number of the claims at issue in the IPR, including Claim 1. In a nutshell, the reason for this was that under pre-AIA 35 U.S.C. 103(c)(1) Edmondson could not be used as 102(e)/103 prior art because Edmondson and the challenged patent were both owned by Merck, and Merck was able to antedate Edmondson as a 102(a)/103 reference with respect to Claim 1 and some of the other claims at issue.

Merck was not able to antedate Edmondson with respect to some of the other challenged claims, including Claim 4, which depends from Claim 1 and recites a crystalline monohydrate form of the (R)-enantiomer of sitagliptin DHP.  I think it is safe to assume that Claim 4 corresponds to the proposed generic product, given that in Canadian proceedings (discussed below) Mylan stipulated that its product would infringe the Canadian equivalent of Claim 4. The Board addressed the merits of Mylan’s assertion that Edmondson (in combination with other prior art) rendered Claim 4 obvious, and concluded that it did not. The Federal Circuit affirmed this conclusion.

This past April, a Canadian court issued a decision finding the Canadian equivalent of Claim 4 not invalid for obviousness and/or insufficiency (i.e., lack of enablement).  Significantly, the Canadian Court found that “[t]he evidence indicates that the [skilled artisan] would not have any specific motivation arising from [Edmondson] to focus on the particular crystalline form of a salt of sitagliptin over the other compounds disclosed within [Edmondson].”

Last month, Merck announced that the U.S. District Court for the Northern District of West Virginia had found the ‘708 patent not invalid and infringed in a Hatch-Waxman infringement suit brought against Mylan (which is now a part of Viatris).  I tried to take a look at that decision, but found that it had been filed under seal.  The case is being appealed to the Federal Circuit, and it will be interesting to see what happens if that appeal results in a decision.  Bear in mind that in patent infringement litigation the accused infringer (e.g., Mylan) is able to rely on prior art (e.g., public use or on-sale events) and grounds for invalidation (e.g., obviousness-type double patenting or lack of enablement) that are not available in IPR proceedings.

CareDx v. Natera: Some Further Thoughts on the Patent Eligibility of Molecular Diagnostics

By Chris Holman

A couple days ago Dennis posted a nice review of the Federal Circuit’s recent decision in CareDx v. Natera, in which he emphasized the fact that the court characterized a number of boilerplate statements in the patent document as “admissions” that the various DNA analysis technologies recited in the claims, e.g., next-generation sequencing (“NGS”) and digital PCR, were “conventional” for purposes of step two of the Alice/Mayo framework. I decided to write this follow-up post to explain why, in my view, these “admissions” in the patent document did not affect the outcome in the case, and that these claims were doomed irrespective of the patent’s characterization of the technologies.

The reason these claims were deemed patent ineligible, in my view, is that they are directed towards a molecular diagnostic method, and, as Judge Moore bemoaned in her dissent from the Federal Circuit’s denial of en banc rehearing of Athena Diagnostics v. Mayo, 927 F.3d 1333 (Fed. Cir. 2019), the Federal Circuit’s current interpretation of the Supreme Court’s decision in Mayo v. Prometheus has “resulted in a per se rule that excludes all diagnostics from eligibility.”  She notes that ‘[s]ince Mayo, we have held every single diagnostic claim in every case before us ineligible.” As such, the outcome in CareDx was, in my opinion, preordained. In fact, it would have been quite unexpected if the Federal Circuit had upheld the eligibility of the claims, given that in Athena Diagnostics all 12 of the judges that heard the case appeared to agree with Judge Moore’s assessment of the current state of affairs at the Federal Circuit regarding the eligibility of diagnostic claims of this type.

Athena Diagnostics is a very interesting decision for those of us concerned about the patent eligibility of molecular diagnostics. It resulted in eight separate opinions, in which all 12 of the judges who decided the case joined, in various combinations. Interestingly, as Judge Moore pointed out, ‘”[n]one of [her] colleagues defend[ed] the conclusion that claims to diagnostic kits and diagnostic techniques, like those at issue, should be ineligible.” In fact, my reading of the decisions is that all of the judges agreed that molecular diagnostics should generally be eligible for patent protection, and that the fact that they currently are not is a significant cause for concern.

There is a split of the court, however, with respect to whether the Federal Circuit has the ability to address the problem without an intervention by the Supreme Court or Congress. A seven judge majority (Lourie, Reyna, Chen, Hughes, Prost, Taranto, and Dyk) believes that the court’s hands are tied, and that Mayo dictates that diagnostic methods are patent ineligible. Judge Lourie, for example, wrote that the court could “accomplish little in [rehearing this case], as we are bound by the Supreme Court’s decision in Mayo.”  Judge Hughes “agree[d] that the language in Mayo, as later reinforced in Alice, forecloses this court from adopting an approach or reaching a result different from the panel majority’s.”

In light of this interpretation of Supreme Court precedent, these judges thought it would be futile to take up the case en banc. For example, Judge Hughes wrote that, while he “agree[d] that the bottom line for diagnostics patents is problematic[,] this is not a problem that we can solve. As an inferior appellate court, we are bound by the Supreme Court.”

The five dissenting judges (Moore, O’Malley, Wallach, Stoll, and Newman), on the other hand, expressed the view that, in fact, Mayo had not rendered all molecular diagnostics patent ineligible per se, and that the Federal Circuit had erred in interpreting Mayo in this restrictive manner. Judge Newman, for example, found the “majority’s position [to be] a flawed interpretation of the Court’s decision in [Mayo].  The Court did not hold that methods of diagnosis are subject to unique patent-eligibility rules. We have mistakenly enlarged the Court’s holding, in substance and in application.”  These five judges would have reheard the case en banc, allowing the Federal Circuit an opportunity to correct this perceived error, and opening up the door for the patenting of at least some molecular diagnostics.

Notably, two of the judges that decided CareDx, Lourie and Hughes, were part of the Athena Diagnostics majority that interpreted Mayo as requiring a finding of patent ineligibility for diagnostic claims of this type. The third judge on the CareDx panel, Judge Bryson, was a senior judge at the time Athena Diagnostics was decided, and did not participate in that decision.

In CareDx, the patent owner tried unsuccessfully to convince the court that the DNA analysis techniques specifically recited in the claims were “unconventional” enough to avoid the strictures of Mayo. While implicitly acknowledging that techniques such as PCR and DNA sequencing are conventional, CareDx basically argued that digital PCR and next-generation sequencing were sufficiently cutting edge at the time of the purported invention as to be not “conventional” for purposes of the Mayo two-part framework. But these techniques were apparently known to those of skill in the art at the time, and under the Federal Circuit’s current interpretation of Mayo I think the court would have found the use of any known method of DNA analysis to be lacking in the “inventiveness” required to meet the standard. While the “admissions” in the patent document provided a convenient route for the court to conclude that the methods were conventional, I think it would have arrived at the same conclusion regardless of any statements made in the patent, given that these techniques were presumably not novel at the time of invention.

Federal Circuit Flips “Negative Claim Limitation” Decision after Change in Panel Composition

By Chris Holman

Novartis Pharms. Corp. v. Accord Healthcare, Inc., 2022 WL 2204163, — 4th —  (Fed. Cir. June 21, 2022)

Here we have a case in which a petition for rehearing by the Federal Circuit leads to a flipped decision that appears to be the consequence of a change in panel composition.

In the original decision, authored by Judge O’Malley and decided January 3, a divided panel upheld a district court’s determination that the patent claims at issue were not invalid for failure to satisfy the written description requirement. The Federal Circuit agreed to rehear the case, but the composition of the panel rehearing the case was altered by the replacement of Judge O’Malley (who retired in March) with Judge Hughes. The reconfigured panel flipped the result of the earlier decision, this time reversing the district court.  The second decision was authored by Judge Moore, the dissent in the original decision. Judge Linn, who sided with Judge O’Malley in the original decision, found himself writing in dissent the second time round.

The relevant issue before the court was whether a negative claim limitation was adequately supported by the priority patent application. The claims are directed towards methods of treating relapsing-remitting multiple sclerosis (RRMS) through the administration of fingolimod (an immune suppressant) “at a daily dosage of 0.5 mg, absent an immediately preceding loading dose regimen.”  The “no loading dose” limitation was added by amendment during prosecution in order to overcome an obviousness rejection.  A loading dose is a “higher-than-daily dose,” usually given as the first dosage in a dosing regimen.   It was undisputed that loading doses were well-known in the medical field generally, and that loading doses have been used with some medicaments used in the treatment of MS.

The priority application does not explicitly mention loading doses, let alone the absence of a loading dose, but the district court nonetheless found implicit support for the negative claim limitation in two examples provided in the specification (one a prophetic human clinical trial, the other an experiment conducted in rats) which disclosed dosage regimens that did not involve the use of an initial loading dose. There was expert testimony to the effect that a person of skill in the art (POSA) reading the examples would have understood them as being “complete,” and as such the fact that the examples do not mention a loading dose implicitly discloses a dosage regimen that is not preceded by a loading dose.

In the original decision upholding the district court’s decision as not erroneous, Judge O’Malley emphasized that the majority was not instituting a “new and heightened standard for negative claim limitations,” and acknowledged that the disclosure need not describe a limitation in haec verba.  Writing in dissent, Judge Moore argued that the “no loading dose” limitation could not possibly find adequate support in a patent specification that fails to even mention loading doses.

Writing for the majority in the second opinion, Judge Moore reiterates her position that the district court clearly erred in finding written description support for the “no loading dose” limitation. While she acknowledges that a negative claim limitation does not necessarily require explicit written description support when the specification describes a reason to exclude the relevant element, e.g., when the specification identifies disadvantages of using that element, or “distinguishes among” the element and alternatives to it, she maintains that the element must at least be disclosed in some form, given that “the hallmark of written description is disclosure.” Judge Moore does not dispute that the written description requirement can be satisfied if a skilled artisan would have understood that the specification inherently discloses the negative limitation, but she found no evidence on the record in this case that a skilled artisan would understand silence regarding a loading dose to “necessarily exclude” a loading dose.

In his dissent, Judge Linn does not so much disagree with Judge Moore’s characterization of the law of written description, as with the way the majority applied that law to the facts of this case. In particular, he complains that majority improperly required the priority application to disclose that the negative limitation in question was “necessarily excluded”.  He argues that it can be sufficient for the specification to merely provide a “reason to exclude” the negative claim limitation.


Induced Infringement and the Section 286 Statute of Limitations

By Chris Holman

Roche Diagnostics Corp. v. Meso Scale Diagnostics, LLC, 2022 WL 1052320, — 4th —  (Fed. Cir. Apr. 8, 2022)

Through its acquisition of BioVeris Corporation, Roche Diagnostics became the owner of various patents relating to immunoassays employing electrochemiluminescence (“ECL”). In spite of its ownership of the patents, however, a jury found that a predecessor of BioVeris (IGEN) had exclusively licensed the patents to Meso Scale Diagnostics, and that Roche was liable to Meso for directly infringing one of the patents, and for inducing infringement of two others. On appeal, a divided Federal Circuit affirmed the jury’s decision with respect to direct infringement, but reversed the judgment of induced infringement, remanding for a new trial on damages. Writing in dissent, Judge Newman would have found that Meso did not have an exclusive license in the patents, and therefore Roche was not liable for either direct or induced infringement. The decision raises interesting issues relating to induced patent infringement and the interpretation of a licensing provision.

Inducement:  In 2003, prior to acquiring BioVeris (and its ECL patents), Roche obtained a nonexclusive license to the patented ECL technology from IGEN in the field of “human patient diagnostics.”  This license required Roche to note this field restriction on its product packaging. Later, in 2007, a Roche affiliate acquired BioVeris (including over 100 patents) for approximately $600 million. Roche announced this acquisition in a press release stating it would now “own the complete patent estate of the [ECL] technology,” giving it “the opportunity to fully exploit the entire immunochemistry market” and ensuring its ability to “provide unrestricted access to all customers.” Roche also prepared a customer letter indicating that the field-restriction labels were “now obsolete” and would be “removed as soon as possible,” but that in the interim customers should “please ignore the restrictions.” Roche subsequently began selling the products without field restrictions.  Meso argued that these actions induced customers to use the patented technology outside of the licensed field of use, i.e., “human patient diagnostics.”

Writing for the majority, Judge Prost explained that the decision to reverse the district court’s judgment with respect to induced infringement rested on two independent grounds: (A) absence of intent, and (B) absence of an inducing act that could support liability during the six-year statute of limitations on collecting back-damages, as set forth in 35 U.S.C. § 286.  (In a 2019 post, Dennis explains why it is correct to refer to the Section 286 limitation on damages as a “statute of limitations.”  For the record, Judge Newman uses the term in her  Roche Diagnostics dissent.)

Regarding absence of intent, the court found that the district court had, in denying JMOL, “incorrectly applied a negligence standard rather than requiring specific intent for inducement.” Judge Prost explained that:

While it’s true that we previously applied a “knew or should have known” formulation, we’ve since made clear that, “to the extent our prior case law allowed the finding of induced infringement based on recklessness or negligence, such case law is inconsistent with Global-Tech and no longer good law.”  …  Under the proper standard, the jury’s inducement conclusion is unsupportable.

The majority went on to explain that a finding of induced infringement was fundamentally inconsistent with the district courts conclusion (made in the context of a JMOL of no willful infringement) that “at no time did Roche have a subjective intent to infringe (or induce infringement of) Meso’s patent rights.”  In particular, the district court found that Roche had reasonably (albeit ultimately incorrectly) concluded that Meso did not have an exclusive license in the patents, and thus that Roche had no liability to Meso for patent infringement. Judge Prost explained that:

In some respects, the intent standard for inducement is akin to the one for willfulness, as both rest on the subjective intent of the accused infringer. … Here, the jury’s verdict of inducement couldn’t have survived JMOL under the proper intent standard because it contradicts the court’s express findings regarding Roche’s subjective belief that it wasn’t infringing or inducing infringement.

The majority further found that Meso had not proven that Roche had committed inducing acts within the Section 286 patent-damages limitations period, which began in April 2011. In particular, Roche’s allegedly inducing acts, i.e., its press release, customer letter, and decision to stop affixing field-restriction labels, occurred solely in 2007.

In sustaining the jury’s verdict of induced infringement, the district court had posited that acts occurring before the damages period could support a finding of inducement if they “continued to have an impact and caused third parties to use the products-at-issue outside of the licensed patient-diagnostics field after April 2011.”  The majority rejected the district court’s “continuing-impact” standard, citing Standard Oil Co. v. Nippon Shokubai Kagaku Kogyo Co., 754 F.2d 345 (Fed. Cir. 1985), and finding that “Roche’s press release, customer letter, and removal of field restrictions cannot support the jury’s induced-infringement verdict because the evidence indicates—and Meso doesn’t dispute—that none of these acts occurred within the damages period.”

Meso argued that Roche had committed inducing acts during the damages period because Roche “sold the products without restrictive labels throughout the damages period.” But the majority found that “sales without restrictive labels are not acts of inducement where, as here, the products have both in-field (non-infringing) and out-of-field (infringing) applications.”

The court further found that:

Even if Standard Oil doesn’t foreclose the district court’s “continuing-impact” standard, we reach the same conclusion because Meso didn’t provide evidence of causation between the allegedly inducing acts (before the damages period) and the direct infringement (within the damages period). Specifically, Meso put forward no evidence that any customers purchasing Roche’s products during the damages period received the 2007 communication and, in reliance on it, used the products out-of-field. …  For similar reasons, Meso’s argument that Roche induced infringement because it “never withdrew” its 2007 guidance also fails, at least because Meso didn’t show that this omission caused customers to infringe.

Readers might find it interesting to compare Judge Prost’s opinion in this case with her dissent in the Federal Circuit’s recent “skinny label” decision, Glaxosmithkline v. Teva, 7 F.4th 1320 (Fed. Cir. 2021) wherein she discusses induced infringement, and particularly her interpretation of the causation element of inducement.

License Scope:  Meso’s exclusive license in the ECL patents arose out of a joint venture agreement between IGEN and Meso Scale Technologies, a company owned by Jacob Wohlstadter (son of IGEN CEO Samuel Wohlstadter).  The agreement specified a “Research Program” for Meso to perform and included the following license provision:

2.1. IGEN Technology. IGEN hereby grants to [Meso] an exclusive, worldwide, royalty-free license to practice the IGEN Technology to make, use and sell products or processes (A) developed in the course of the Research Program, or (B) utilizing or related to the Research Technologies; provided that IGEN shall not be required to grant [Meso] a license to any technology that is subject to exclusive licenses to third parties granted prior to the date hereof. In the event any such exclusive license terminates, or IGEN is otherwise no longer restricted by such license from licensing such technology to [Meso], such technology shall be, and hereby is, licensed to [Meso] pursuant thereto.

With respect to the directly infringed patent, the majority affirmed the district court’s determination that the patent was “developed in the course of the Research Program,” and therefore, under “prong A” of the provision, Meso had exclusive rights in the asserted claim.  The court noted that “the work that was done in this patent was part of the research program,” and that Roche had not provided any persuasive reason why the asserted claim wasn’t “developed in the course of the Research Program.”  According to the majority:

The most Roche offers on this score is a footnote arguing generally that “the evidence at trial was insufficient for the jury to find that Meso held exclusive rights to the entirety of the ‘939 patent claim” and citing further course-of-conduct evidence. But this argument, “made in passing only in a footnote, is not sufficient under our precedents to preserve an argument for review.”

The majority found it unnecessary to decide whether Meso had an exclusive license in the patent claims that were only infringed indirectly, given that the district court’s finding of induced infringement had been reversed.

Writing in dissent, Judge Newman argued that Roche was not liable for infringement of any of the patents, since, under her interpretation of the license provision, Meso did not have an exclusive license to any of them.  She found the jury’s verdict to be “contradicted by the activity of all parties at the time of the 1995 license and the ensuing twenty-two years (citing Old Colony Tr. Co. v. City of Omaha, 230 U.S. 100, 118 (1913) (The practical interpretation of a contract by the parties to it for any considerable period of time before it comes to be the subject of controversy is deemed of great, if not controlling, influence)).”

Judge Newman also took issue with what she she saw as the majority’s decision to “disregard[] the undisputed evidence of [Meso]’s acceptance of Roche’s rights, because Roche mentioned that evidence in a footnote.” In her view:

Although presented in footnotes, these arguments were fully developed. The majority’s holding that Roche forfeited this issue defeats “the orderly administration of justice,” instead presenting a trap for the unwary. The judicial obligation is to seek truth and justice, even from footnotes.

Clearly, an attorney addressing the court should think twice before using a footnote to make a substantive point.

The Definiteness Implications of Using “Examples” to Define Claim Terms

by Chris Holman

ImmunoGen, Inc. v. Hirshfeld, 2022 WL 885774, (Fed. Cir. Mar. 25, 2022) (nonprecedential)

The patent application at issue in this case claims a method of treating a cancer patient by administering mirvetuximab (an immunoconjugate drug) “at a dose of 6 milligrams (mg) per kilogram (kg) of adjusted ideal body weight (AIBW) of the patient.” The purported invention arose out of the discovery that administration of mirvetuximab at the recited dosage significantly reduces the severe ocular side effects that were observed during Phase 1 clinical trials when the drug was administered at a dose of 7 mg per kg of the patient’s total body weight (“TBW”).  After the Patent Trial and Appeal Board (“Board”) affirmed the examiner’s rejection of the pending claims for obviousness and obviousness-type double patenting, the applicant (ImmunoGen) filed a § 145 suit in the Eastern District of Virginia challenging the rejections.  The district court determined on summary judgment that the claims are “fatally indefinite and fatally obvious” as a matter of law.  On appeal, the Federal Circuit vacated the grant of summary judgment and remanded for further proceedings.

The district court’s indefiniteness ruling was based on the claims’ recitation of “AIBW,” a term which the court found was not defined in the application in manner that would inform a skilled artisan, with reasonable certainty, as to the scope of the invention (the Nautilus standard).  The application defines AIBW as “a size descriptor that accounts for sex, total body weight, and height.” It further defines ideal body weight (“IBW”), which is used to calculate AIBW, as “an estimate of weight corrected for sex and height, and optionally frame size.”  The AIBW and IBW definitions each includes a specific formula, introduced by the phrase “for example,” for calculating the respective values.

The formulas are reproduced below in the form of equations:

AIBW = IBW + 0.4(Actual weight in kg – IBW)

IBW (male) = 0.9(Height in centimeters) – 88

IBW (female) = 0.9(Height in centimeters) – 92

These “example” formulas were also reproduced in Example 4 of the application, which relates to the dosing of mirvetuximab.

In support of its decision finding the claims indefinite, the district court relied primarily on the fact that the definitions section of the application preceded the AIBW formula with the language “for example,” which the court found “ma[de] clear that there are multiple ways to calculate AIBW,” thereby “leav[ing] a skilled artisan to wonder or to guess whether the formula provided is the only one covered by the ’809 Application.” This uncertainty was, in the view of the district court, compounded by: (1) similar “for example” language accompanying the IBW formula; (2) the disclosure that IBW corrects “for sex and height, and optionally frame size”; and the incorporation by reference in its entirety of “Green,” an article that discloses several methods for calculating IBW and lists correction factors, each specific to a different drug, that can be used to adjust IBW to AIBW.

On appeal, the Federal Circuit found that the material factual findings underlying the district court’s definiteness ruling were far from undisputed. In particular, ImmunoGen had identified other intrinsic evidence a skilled artisan would consider in determining the scope of the claims, including that: (1) the claims and specification are drawn to a specific dosing regimen for a specific immunoconjugate, which is significant in light of expert testimony that the correction factor used to calculate AIBW is drug-specific; (2) Example 4 describes dosing mirvetuximab in accordance with the claimed method and uses the same AIBW and IBW formulas disclosed in the definitions section; and (3) during the prosecution of the ’809 Application, the USPTO never disputed the definiteness, or gave any indication it failed to understand the meaning, of the now-allegedly indefinite term. ImmunoGen also presented extrinsic evidence regarding the knowledge of a skilled artisan. For instance, both parties’ experts testified that AIBW dosing involves drug-specific formulas and correction factors.

The Federal Circuit also found that the district court had erred in concluding that there was no disputed question of material fact with respect to obviousness.  It was undisputed that AIBW dosing had not previously been used for mirvetuximab, or for that matter any other immunoconjugate drug.

If on remand the court ultimately finds the claims indefinite for defining a critical claim limitation in terms of an “example,” it would not be the first time that the Federal Circuit has flagged this as an issue.  In Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364 (Fed. Cir. 2014), the Federal Circuit held claims invalid for indefiniteness because the specification failed to adequately define the claim limitation “unobtrusive manner that does not distract a user.”  While “recognizing that a patent which defines a claim phrase through examples may satisfy the definiteness requirement,” the court “decline[d] to cull out a single “e.g.” phrase from a lengthy written description to serve as the exclusive definition of a facially subjective claim term.”  The court observed that “[h]ad the phrase been cast as a definition instead of as an example—if the phrase had been preceded by “i.e.” instead of “e.g.”—then it would help provide the clarity that the specification lacks.”

Still, I think that Interval Licensing can be readily distinguished over ImmunoGen, in that Interval Licensing’s “unobtrusive manner that does not distract the user” claim limitation seems much more “facially subjective” than ImmunoGen’s “adjusted ideal body weight.”