SCHRÖDINGER’S POLYMORPH: WHEN A CRYSTALLINE FORM CLAIM IS OBVIOUS AND INVALID

Salix Pharmaceuticals, Ltd. v. Norwich Pharmaceuticals Inc., No. 22-2153 (Fed. Cir. 2024)


“Schrödinger’s cat,” is a paradoxical thought experiment devised by physicist Erwin Schrödinger, while debating quantum superposition in 1935. Oversimplified, in the thought experiment, there is a cat in a box, and you have no way of knowing what physical state the cat is in, like a quantum wave function, until you open the box and observe it.

While studying polymorphic forms, like Schrödinger’s hypothetical [albeit a long stretch], you do not know what form a solid compound is until you measure it with x-ray crystallography. However, unlike Schrödinger’s hypothetical, you may have a reasonable expectation of succeeding to figure out what form your compound is depending on the prior art and knowledge of a person of ordinary skill.

Shifting from quantum to organic chemistry patent law, if there is a reasonable expectation of success in characterizing a known crystalline product for potential polymorphism using routine, conventional methods and skill, then a claim to that crystalline product would be invalid for obviousness. Such was the decision in Salix Pharmaceuticals, Ltd. v. Norwich Pharmaceuticals Inc., No. 22-2153 (Fed. Cir. 2024).

Salix claimed a specific crystalline form (form β) of rifaximin. The United States patent and Trademark Office (USPTO) granted Salix a patent on it.  However, when litigated, the United States Court of Appeals for the Federal Circuit (CAFC) affirmed the District Court of Delaware’s finding that Salix’s claims to rifaximin form β were invalid for obviousness.*

“The difference between the prior art and the claims is thus effectively nothing more than the performance of routine characterization to identify the polymorphic forms that result from the known Cannata processes.”

Salix Pharmaceuticals, Ltd. v. Norwich Pharmaceuticals Inc., No. 22-2153 (Fed. Cir. 2024), at 15.

In other words, you cannot claim ownership of a compound just by making the expected crystalline form using someone else’s process and taking an x-ray crystal structure of it and giving a Greek letter name.

Background

  • Salix markets Xifaxan® (rifaximin), and Norwich wanted to sell a generic version.
  • Xifaxan® is a formulation of rifaximin crystalline form β.
    • Polymorph β is a commonly produced polymorph.
    • Polymorph β the most stable form of rifaximin.
  • Disputed patent claims: Claim 4 of U.S. Patent No. 7,612,199 and Claim 36 of U.S. Patent No. 7,902,206.
    • Claim 4. Rifaximin in polymorphic form β, wherein the rifaximin has x-ray powder diffraction pattern peaks at about 5.4°; 9.0°; and 20.9°2θ and wherein the rifaximin has a water content of greater than 5%.
  • Prior art: Cannata et al. U.S. Patent No. 4,557,866.
    • Although Cannata does not discuss rifaximin’s crystal structure in detail, it does disclose several preparation protocols for rifaximin that include solvents used for crystallization.
    • Experts testified that Cannata’s preparation of crystalline Rifaximin would have yielded its β form. But they could not say it would every time.
  • Rifaximin was a known compound with a known, useful activity (antibiotic).
    • While rifaximin was a known antibiotic, Salix owns rights to patents covering new method of use (hepatic encephalopathy). Salix won on appeal for such method-of-use claims.
  • Experts testified that Cannata’s preparation of crystalline rifaximin would have easily made and taken an X-Ray diffraction pattern to determine that rifaximin was in its β form.
    • The experts could not convince the judge that the prior art process would produce rifaximin form β “every time.” If they could, then Salix’s claims would have been anticipated (not novel) as inherently present in the prior art.
    • Although the experts could not convince the judge of the certainty of form β (novelty), they at least convinced the judge that form β was reasonably expected (obviousness).

    CAFC Opinion Discussion

    The CAFC decided that “the district court found a reasonable expectation of success in characterizing the crystalline product of Cannata for potential polymorphism using routine, conventional methods and skill [Salix Pharm., Ltd. v. Norwich Pharm., Inc., Civil Action No. 20-cv-430-RGA, (D. Del. Apr. 29, 2021), at *6–7].  We see no clear error in that conclusion. Indeed, Salix has done no more than combine known elements of the prior art to verify readily accessible information concerning a compound already in the hands of those of ordinary skill in the art, and such routine efforts do not justify removing this polymorph from the public domain. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 427 (2007); see also Pfizer, 480 F.3d at 1367−68.”

    The District Court supported its factual determinations of obviousness with expert testimony that:

    (1)  a skilled artisan would have had good reason to characterize the crystalline rifaximin obtained by following the Cannata protocols,

    (2)  such characterization was routine and could have been performed “in one day,” and

    (3)  doing so would have led the skilled artisan to have “detected rifaximin β.” 

    Salix argued that a person of ordinary skill in the art would not have “expect[ed] to succeed” because, as of the critical date, the polymorphic nature of rifaximin had not yet been reported and the identity of the β form remained undisclosed. They further argue that a skilled artisan would not have been able to predict which polymorphic form Cannata made. This argument was flawed. The CAFC states that Salix’s is incorrect in framing of the issue, as it suggests that no unknown entity could ever be obvious, as one cannot reasonably expect what was hitherto unknown.


    * In the same appeal, The CAFC did affirm the District Court’s finding that Salix’s other claims to methods of treating hepatic encephalopathy were valid and nonobvious.

    † Whether or not there would have been a reasonable expectation of success is a question of fact. “Whether or not there would have been a reasonable expectation of success is a question of fact, (IXI IP, LLC v. Samsung Elecs. Co., 903 F.3d 1257, 1262 (Fed. Cir. 2018)), which we review for clear error, Hospira, 946 F.3d at 1328. We review the ultimate conclusion of obviousness de novo.” Did the Justices themselves believe that the claims were obvious? Unknown. The CAFC perhaps equivocated or sidestepped the question. The justices did not say that they themselves believe that the polymorph claims were obvious. Rather, they merely said that they found no clear error in the District Court’s finding of obviousness. 

    ‡ The CAFC did not opine on whether or not the polymorph claims were invalid for being inherently anticipated (§102). The court said that they did not need to go that far since they already determined that the claims were invalid for obviousness (§103). The district court said that the polymorph claims were not anticipated as being inherent because Norwich did not prove with clear and convincing evidence that the prior art method would produce rifaximin form β “every time.” The inherency issue may deserve its own post. Question for discussion: Does the “every time” requirement go too high for “clear and “convincing evidence?” Perhaps requiring a specific result Every time may go up to the realm of “beyond a reasonable doubt,” which is not the level of burden of proof for patent law. Recall last year’s discussion of the Amgen case where there were arguments about how many examples enable the “full scope” of a claim. Stay tuned.

    Additional Information

    OrganicPatents.com page on Obviousness of Stereoisomers &Purified Compounds

    See also PatentDocs’s post: https://www.jdsupra.com/legalnews/salix-pharmaceuticals-ltd-v-norwich-3362384/.


    May 8, 2024

    10-Month Rule: Federally Funded Provisional Patent Applications

    File your non-provisional patent application early, within 10 months of filing your provisional application if your invention was conceived using Federal funding.

    ISSUE: What might be the consequences for a contractor after failing to timely file a non-provisional patent application within 10 months of filing its provisional patent application?  

    RULE: The agency can request conveyance of title upon contractor’s omission to timely file patent applications in any country.1 Timely filing means filing a non-provisional patent application within 10 months of filing a provisional patent application (the “10-Month Rule”).

    RULE NEEDS CLARIFICATION: Though the 10-Month Rule may sound straightforward, the rule may conjure further issues. The authority is found in the Federal Regulations at 37 C.F.R. 401.14(c)(3). However, the C.F.R.’s wording may leave matters open for debate.

    Unfortunately, guidance from other sources appears to be sparse. The 10-Month Rule is not specifically recited in 35 U.S.C. § 202 and the Federal Statutes that codified the Bayh-Dole Act. Furthermore, the manual of Manual of Patent Examining Procedure (MPEP) does not appear to refer to the 10-Month Rule. Furthermore, there does not appear to be any case law opining on the 10-Month Rule.2 This is likely because no Federal Agency has yet to enforce the 10-Month Rule, analogously to how no Federal Agency to-date has not activated any march-in-rights they may have under the Bayh-Dole Act. At least no litigation has arisen after an enforcement of the 10-Month Rule.

    ISSUES FOR CLARIFICATION:

    Timing?

    QUESTION: When can the Federal agency request conveyance of title? The question may be further split up into two questions of when:

    (1) From what time?; and

    (2) Until what time?

    ANALYSIS (1): The C.F.R. clearly shows that the Federal agency may request conveyance of title from the time the contractor fails to timely file its non-provisional application. This means that the Federal agency may request conveyance of title after the 10-month deadline if the contractor has not yet filed its non-provisional patent application.

    ANALYSIS (2): The C.F.R. does not provide clear guidance. The Federal agency clearly my request title from at least 10 months to 12 months (i.e., the Statutory deadline to file in the US/PCT).  But the Federal agency may not clearly continue to have the right to request conveyance after 12 months, even if the contractor filed its non-provisional application in compliance with the statutory 12-months anyway.

    DISCUSSION:

    The 10-Month Rule makes sense under the scenario where a contractor has not filed the non-provisional and the time is now 11-months from the contractor’s provisional application filing date. In this scenario, I can see the Federal agency saying: “You did not file it after 10-months, it is now 11-months. This invention is ours now. We are going to file it ourselves and own it 100% now. And by the way, you are not getting it back.”

    What I believe may remain ambiguous, is whether or not the federal agency can still require conveyance of resulting non-provisional application even if the non-provisional application was filed anyway, after 10 months, yet before 12 months. One could argue that, yes, the Federal agency can, at any time over the next 20 years, take the patent away from the contractor. That would be cruel.  However, while I believe that Federal agencies such as the NIH would not be so cruel,3 perhaps a potential infringer might indeed be so cruel to a patent owner by asking a court to rule that the patent owner forfeited its rights to the NIH, long after a patent is granted. A countering argument is that, no, federal agencies cannot do so, because that was not what the rules intended.

    Patent Validity and Enforceability

    QUESTION:

    Is a patent valid and enforceable if it resulted from an non-provisional application that was filed after 10 months of the provisional application, yet filed before the statutory 12 months?

    ANALYSIS:

    • There should not be any challenges to the enforceability or the validity of such a patent because it complied with a Federal Statute, even though it may not have complied with a Federal Regulation.
      • This would be contrary to the intent of the Federal Regulations, which appear to have been intended to support the policy of keeping patent applications alive rather than letting them lapse and go abandoned.
    • The Federal Agency would not want the resulting non-provisional application or patent to be then held invalid or unenforceable.  The 10-Month Rule is in place to ensure that a Federal Agency may rescue an invention after a contractor fails to file a non-provisional application after 10 months. The reason for the rule being 10 months is to allow the Federal agency to wrestle control (ownership) of the invention and still have 2 months of time to file the non-provisional application by itself, after the contractor neglected to do so.

    1. See, https://www.nist.gov/tpo/bayh-dole-act/2018-faqs. See also, https://www.fenwick.com/insights/publications/avoiding-loss-of-title-to-inventions-m[…]al-funding-as-new-bayh-dole-requirements-affect-patent-rights –  Fenwick & West, LLP. ↩︎
    2. I checked Westlaw & Lexis at the Worcester Law Library. But I may be rusty. ↩︎
    3. Disclosure: I received a Post-Doctoral Research Grant from the NIH in 2000. ↩︎

    Inherency & Therapeutic Mechanisms: Reviewing In re Couvaras – (With No-Frills Diagrams)

    Q:  When can you patent a composition’s mechanism of action?

    A:  When the mechanism is not inherent in a known use of the composition.

    “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.”

    In re Couvaras, 22-1489 (Fed. Cir., 2023)

    In re Couvaras, 22-1489, 2023 WL 3984753 (Fed. Cir., June 14, 2023)

    Precedential Opinion by Circuit Judge Lourie; joined by Circuit Judges Lourie, Dyk, and Stoll

    The United States Court of Appeals for the Federal Circuit (CAFC) agreed with the Patent Trial & Appeals Board (PTAB), and the USPTO examiner, that claims in U.S. Patent Application No. 15/131,442 (US2016/228,393), which recites methods of increasing prostacyclin release in the systemic blood vessels of a human with essential hypertension to improve vasodilation, were obvious because the claims relate to combatting hypertension with known antihypertensive agents and merely disclose their previously unappreciated mechanism of action.”

    High Level Summary

    The prior art taught that GABA-a agonists and ARBs reduce anti-hypertension. Dr. Couvaras discovered that GABA-a agonists and ARBs reduce anti-hypertension, in part, because they increase prostacyclin and promote vasodilation. Dr. Couvaras applied for a patent claiming a method of increasing prostacyclin in an individual with hypertension to improve vasodilation by providing an ARB and a GABA-a agonist.  However, the USPTO rejected the claims because the element of increasing prostacyclin was inherent in the well-known prior art method of independently treating hypertension with an ARB or a GABA-a agonist. 

    Visualizing the case with diagrams

    Now let’s skeletonize the elements of this case down to arrow diagrams. We don’t need too many facts getting in the way of this good story. 🙂 *

    Claim 11 (abridged): A method of increasing prostacyclin in an individual with hypertension to improve vasodilation by providing an ARB and a GABA-a agonist. 

    A = Providing an ARB and a GABA-a agonist 

    X = Increasing prostacyclin

    B = Vasodilation (treating hypertension)

    * But seriously, although I am scientist reluctant to loose any nuance, technical terms such as Angiotensin II Receptor Blocker (“ARB”) can be distracting in analyzing the the law in case.  Also, I believe that knowing the claims recite a combination therapy is superfluous and thereby distracting itself. (At least I found them distracting at first. Maybe that’s just me. Please work with me for now.) The CAFC’s rule of law works for both mono and combo therapies. See below for a discussion regarding combination therapies.

    The overall goal is to get from A to B. Doctors already know how to get from A to B. It is prior art. No argument there. Then an inventor discovers that X is the mechanism of action that leads to B.

    Doctors did not already know that going from A to B involves X. This is not taught in the prior art.  A→X is a genuine new discovery. No argument there either.

    Now you have  A→ X→ B.

    Although the discovery of A→ X is indeed new, inventors should not be able to patent a claim to the discovery. Even though doctors did not know it, doctors were inherently doing the process of A→ X→ B by simply prescribing A to treat B.  It makes sense that someone should not be able to patent a claim to  A→ X→ B, or even simply A→X, then suddenly prevent doctors from prescribing A→ B, which they have been doing all along.

    New methods and mechanisms of action may still be patented

    In re Couvaras, however, does not mean that all mechanisms and new uses are not patentable. New uses for old compounds May still be patentable. For example, an inventor may discover that A also renders the benefit of C, and that A affects B by going through mechanism Y.

    In this example, the inventor may be able to patent a claim to A→C.

    If an inventor simultaneously discovers that A→C goes through the mechanism “Y” then they may be able to patent a claim covering both A→C, A→Y,  and A→Y→C.  

    NOTE: The inventor should file both claims simultaneously so the inventor’s disclosure of A→C does not block the claim to A→Y. If not, then the inventor will have the same problem from In re Couvaras.

    In summary, patentability of mechanisms (X/Y) rest on the whether the overall benefit (B/C) is unexpected from the known composition (A).

    Secondary Considerations

    Of course, secondary considerations provide some leniency. But the secondary considerations surely need to be compelling.

    “To establish unexpected results, Couvaras would have needed to show that the co-administration of GABA-s agonist and an ARB provided an unexpected benefit,” such as, e.g., better control of hypertension or less toxicity.

    Failure of others: “The purported failure to achieve prostacyclin increase through pursuing an unrelated goal did not establish the non-obviousness of the claimed method.”

    No long felt need: The anti-hypertensive agents were admitted to be available already.

    “The pending claims of the ’422 application literally recite methods of increasing prostacyclin release in the systemic blood vessels of a human with essential hypertension to improve vasodilation. That increased prostacyclin release is achieved by co-administering two well-known types of antihypertensive agents: a GABA-a agonist and an Angiotensin II Receptor Blocker (“ARB”). In reality, the claims relate to combatting hypertension with known antihypertensive agents and claiming their previously unappreciated mechanism of action.”

    Novelty vs. Obviousness: Inherency

    Q: Why is inherency in a case about obviousness and not about novelty?

    A: Here is where the combo-therapy aspect comes in. A combination of two known compounds that render the same benefit is obvious. Dr. Couvaras argued that the discovery of the compounds’ mechanism of action overcame the obviousness rejection. Essentially the argument tried to convince the examiner that each mono therapy was novel. With two novel monotherapies in hand, reasoning follows that combination of two novel monotherapies would have been non-obvious.


    Post Script

    On bright side, The USPTO awarded Dr. Couvaras with U.S. Patent No. 9,339,542 in his earlier application. Composition claims to combinations were non-obvious.

    Granted Claim 1:  A composition effective to relax Smooth muscles in an individual in an altered state, the composition comprising: a dosage of GABA or GABA-a analogue; and a dosage of at least one of an ACE inhibitor and a ARB combined with the dosage of GABA or GABA-a analogue into a deliverable form.


    Small Molecule Lens for Viewing Amgen v. Sanofi

    The U.S. Supreme Court’s opinion in Amgen v. Sanofi (No. 21–757, Decided May 18, 2023) was indeed a big deal. From a small molecule chemistry perspective however, I do not believe that the Amgen decision will alter chemical patent prosecution practice regarding enablement law. True, applications may need even more examples to enable small molecule genus claims. But providing enough examples to enable claims has always been a challenge. And we have been already progressively honing our strategy likewise along with the USPTO’s progressively stringent requirements. Meanwhile, patent practitioners typically do not describe small molecules in functional terms anyway.

    Imagine Amgen’s claim 1 of U.S. 8,829,165 (the ’165 patent) being written for a small molecule.

    1.    A small molecule that binds to PCSK9, wherein the small molecule binds an epitope on PCSK9 comprising at least one of residues 237 or 238 of SEQ ID NO: 3, and wherein the small molecule blocks binding of PCSK9 to LDLR.

    I am confident that most chemical patent agents and attorneys would expect such a claim to fail as not enabled.  No quantity of exemplary compounds can enable the full scope of covering any small molecule.

    Idenix v. Gilead

    Regarding enablement of small molecules, the law still stands from the Federal Circuit’s decision in Idenix Pharmaceuticals LLC v. Gilead Sciences Inc. (Fed. Cir. 2019); 941 F.3d 1149 (2018 WL 922125). Prior to Amgen, the U.S. Supreme Court refused to hear Idenix’s appeal [cert. denied, 141 S. Ct. 1234 (2021) No. 20-380]. 

    Please see my earlier post: Idenix v. Gilead: Split CAFC Panel at Least Agrees – Valid or Not, Either Way it’s Idenix Loss – Claims Too Broad.

    Recall in Idenix, all three justices– including Justice Newman – agreed that Idenix did not enable the claims with regard to the claim’s infringed elements. Justice Newman disagreed, however, with the majority’s ruling that the claims were invalid. Instead, she argued that the claims should have been ruled to be unenforceable over the infringing product rather than be draconianly ruled as invalid as a whole.  I would tend to agree with Justice Newman. Idenix should be at least able to enforce their claims on some other competing product that would be covered by the enabled embodiments. However, I would tend agree with the majority if there were a broad claim to any small molecule defined by functionality alone, without a structure. I don’t believe such a claim should be valid, if not for enablement, perhaps for insufficient written description requirement.

    Idenix claimed a method for the treatment of a hepatitis C virus infection by administering an effective amount of a purine or pyrimidine β-D-2′-methyl-ribofuranosyl nucleoside or a phosphate thereof. However, none of their examples included a 2′-methyl “up” / 2’- fluoro “down” analog like Gilead’s sofosbuvir (Solvadi®). Rather, most examples showed 2′-methyl “up” / 2’- hydroxyl “down” analogs.

    As Justice Gorsuch opined, “in some cases, disclosing that general quality may reliably enable a person skilled in the art to make and use all of what is claimed, not merely a subset.” Channeling SCOTUS’s preference for seeing a common-quality within the claims, the common quality for Idenix would probably have been the 2’- fluoro “down” element, and not just the broad 2′-methyl element.

    Even prior to Amgen, chemical patent practitioners have been keen to include so-called common qualities in core aspects of generic structure formulas. Skilled patent practitioners draft intermediate and narrow sub-generic formulas for embodiments in case broad generic formulas are challenged. Such intermediate formulas often surround a preferred set of species.  The preferred set of species often have a common quality that may make them more active or stable than other series of compounds. Seek out your favorite medicinal chemist. They can explain it better than I can.

    Examples

    For example, a patent application may include a generic formula that recites the broad term “aromatic group.” Meanwhile, the patent application should also include backup provisions such as a sub-generic formula that narrows the term “aromatic” to “heteroaromatic.” Furthermore, the application should include an even narrower backup embodiment wherein the “heterocyclic group can be a specific heterocycle such as pyridine, pyrimidine or pyrazine. The scope of the generic formula would be guided by the compounds exemplified in the application.

    In one hypothetical scenario, a claim to any aromatic group may fail if only heteroaromatic groups are shown in examples. In a further scenario, a claim to a heteroaromatic group may fail if only pyridines are exemplified. Perhaps pyrimidines or pyrazines, with two nitrogens, may have significantly different functional properties than a pyridine having only one nitrogen.

    As before Amgen v. Sanofi, a greater variety of exemplary compounds provides a stronger argument for enablement.

    [ I intend to add more discussion soon. Check back. Thank you for reading! ]

    Amgen Throws Patent Attorneys Under Bus

    Chemists would not routinely rely on the statements of patent lawyers.

    Amgen v. Sandoz, 22-1147 (CAFC, 2023)

    Please pardon my delay in posting. I needed to check my wall to see if my diploma was still hanging there. Yes, it is still there. Like many of my fellow patent attorneys, I have a PhD in chemistry. Being a patent attorney and a chemist is not mutually exclusive. To be fair, my laboratory technique might be quite rusty after 20 years behind a desk. But I still consider myself 100% a chemist.

    Twice, Amgen’s litigators successfully argued that Amgen’s own patent prosecutors were wrong and should be ignored. First, Amgen persuaded the court to ignore disclosure in the patent application specification regarding purification processes using crystallization. Second, Amgen persuaded the court to ignore statements that their European Council made to the European Patent Office (EPO) regarding which products resulting from Example 2 of Amgen’s U.S. Provisional Application 60/366,515.

    Patent attorneys often worry about potential adverse statements that anybody makes during prosecution of patent applications. Keep statements and arguments minimal because, once in writing, you cannot take them back. This case appears to be a rare exception. Depending on whose side you’re on, perhaps it is refreshing that cases such as this show that potentially detrimental statements may be ignored once in a while provided the right evidence.

    Otezla® (apremilast) ANDA litigation

    Background

    Apremalist is an optically pure dextrorotary “(+)” enantiomer of 2-[1-(3-ethoxy-4-methoxyphenyl)-2-methylsulfonylethyl]-4-acetylaminoisoindoline-1,3-dione, having its
    stereo center in the “S” conformation. Stereoisomers regarding apremalist are a big deal because of their similarities to thalidomide.

    The dispute arose from Sandoz’s filing an Abbreviated New Drug Application (ANDA) to sell a generic version of Amgen’s Otezla® (apremalist), a PDE-4 inhibitor used for treating psoriasis.

    Amgen then sued Sandoz to enforce, among others, U S. Patent 7,427,638 claiming a pharmaceutical composition comprising the (+) enantiomer, and U.S. Patent 10,092,541 claims a crystalline solid form of the (+) enantiomer (Form B).

    There were several other issues in this opinion. One that I have spent much time considering is the issue of patenting of stereoisomers.  Look out for my subsequent post to the page “Obviousness of Stereoisomers & Purified Compounds” regarding the decision in this case.

    Priority Claim

    U S. Patent 7,893,101 claims priority to earlier provisional patent application 60/366,515. Sandoz argued that the priority claim was invalid because Example 2 in the provisional application, instead of making only crystalline Form B, also made Form C. Sandoz cited as evidence Amgen patent council’s statements to the EPO stating that Example 2 made both forms. However, counsel’s statement was wrong because Example 2 indeed only made Form B. Amgen was allowed to present data to prove it, including thirteen third-party experiments. With the data as evidence, Amgen was able to take back their erroneous, detrimental statement.

    Non-Obviousness

    Sandoz argued that Amgen’s claims to optically pure compound were obvious because statements in the specification about the separation of the enantiomers. The Statements made the process of isolating enantiomers sound routine. However, Amgen was able to persuade the court that isolating the (+) enantiomer was not routine because, contrary to the specification, formation of chiral salts was not viable. In other words, oversimplified colloquially, the patent attorney drafting the application made the invention sound too easy describing techniques that real chemists would know actually would not work.

    Stereogenic Oxygen!

    I have been updating my page on patentability / non-obviousness of chiral compounds. While working on it, I read about a new molecule ─ a chiral triaryloxonium ion ─ in Chemical & Engineering News (C&EN). Astoundingly, the stereocenter is the oxygen, rather than a carbon, the atom most famous for its chiral capabilities. Chemists synthesized the first stable molecule whose chirality is solely attributed to a stereogenic oxygen. They published their work in Nature. See, O. Smith et al., Control of Stereogenic Oxygen in a Helically Chiral Oxonium Ion, Nature, 615, 430–435 (2023). 

    Link to C&EN article: This New Molecule Owes its Chirality to Oxygen Alone

    Can someone patent a chiral oxonium ion?

    We do not know if the chemists filed a patent application claiming the composition. But that didn’t stop me from speculating as to such a possibility. I think that a patent application claiming a chiral oxygen would be robust. Firstly, the inventors reduced the molecule to practice. They physically made it. It surely is not an abstract idea. Secondly, if the molecule is truly the first stable molecule, then novelty should be no problem. Thirdly, I think that such a compound is non-obvious and inventive.

    Might a chiral oxygen be obvious?

    Let’s focus on non-obviousness. Might a chiral oxonium ion be obvious? I think that, most likely, a chiral oxonium ion would not be obvious. As noted on Organic Patent’s page, Obviousness of Stereoisomers & Purified Compounds, critical support for arguing non-obviousness includes evidence of unexpected properties and difficulties associated with resolving compounds. Other secondary considerations / “Graham” factors are super helpful too, such as long felt but unsolved needs. The articles cited above have an abundance of such evidence.

    Below are a few powerful quotes:

    • “Oxygen has been less cooperative.”
    • “Oxonium ions … have the potential to be chiral, but they are notoriously reactive”
    • “The few previous examples of chiral oxonium ions are too unstable to be isolated … so the search for chiral oxonium ions languished in the literature”

    Gilead Wins Another Sofosbuvir Challenge: U. Minnesota v. Gilead

    Regents of the U. of Minnesota v. Gilead Scis., Inc., 2021-2168, — F.4th — (Fed. Cir. Mar. 6, 2023)

    The Court of Appeals for the Federal Circuit (CAFC) analyzed whether the written description found in UMN’s priority applications supported the claims in the resulting patent # US 8,815,830. The CAFC said no.

    While the ‘830 patent claims covered sofosbuvir, The CAFC affirmed an IPR’s invalidation of U. Minnesota’s claims because they could not properly claim priority to its provisional application. The reasoning was that the provisional with its nebulous multiple dependent claims, that were themselves dependent on further multiple dependent claims, did not adequately describe the subgenus eventually claimed in the non-provisional application.

    See Patently-O’s posts for more:

    March 7, 2023 — Laundry Lists of Components are Insufficient Written Description for a Particular Combination | Patently-O (patentlyo.com)

    March 9, 2023 — Multiple dependent claims, blaze marks, and ipsis verbis support | Patently-O (patentlyo.com)

    SOVALDI® (soh-VAHL-dee) (sofosbuvir)



    Said Goodbye to Ribbons – Now Say Goodbye to Paper: USPTO Officially Transitions to Issuing Electronic Patent Grants in 2023

    Get ready for Electronic Patent Grants!*   

    * And be ready to file continuations or divisionals earlier.

    USPTO-Ribbon small

    Recently in 2018 [okay perhaps ancient history to some] the USPTO stopped attaching actual ribbons to issued patents. Now the USPTO will stop automatically printing paper copies. This is of course good news for trees. This is also good news for applicants who want applications issued more efficiently. However, applicants need to be ready to file any continuing applications earlier than they have been accustomed because the USPTO will issue patents more quickly after providing applicants with a Notice of Issuance. Meanwhile, applicants still need to file continuing applications before issuance.

    Electronic Patent Grants – When:

    Effective April 18, 2023, the USPTO Officially Transitions from issuing patent grants on paper to Issuing electronic patent grants (Federal Register).

    Transition Period – USPTO will still provide free ceremonial copies

    • The USPTO will provide patentees a ceremonial paper copy of the issued patent during the transition period as a courtesy, free of charge.
    • The ceremonial paper copy resembles the paper patent that the USPTO traditionally provided to patent applicants as the issued patent.
    • The ceremonial paper copy will be bound with a cover sheet with both an embossed seal and the signature of the USPTO Director.
    • Length of Transition Period? TBD – Do not know.

    $$ After Transition Period

    • The ceremonial paper copy will be available for purchase for a nominal fee after the transition period, in addition to the presentation copy and certified copy.
    • How much is the “nominal fee” for a “ceremonial” copy? TBD –  Do not know. Though a “presentation copy” is presently $25.

    BE READY TO FILE CONTINUING APPLICATIONS!

    Patent Prosecution Best-Practice Note:  File Continuing applications (CON/DIV) as early as possible. Applicants will not have as much time between receiving an Issue Notification and seeing the patent office issue the granted patent.

    Warning from the USPTO:

    “The USPTO will issue the patent shortly after the payment of the issue fee. As a result, applicants will have less time, after the payment of the issue fee, to file continuing applications, Quick Path Information Disclosure Statements, or petitions under 37 CFR 1.313(c) to withdraw an application from issue. Therefore, the best practice would be for applicants to file these submissions as early as possible. Preferably, continuing applications should be filed before the payment of the issue fee. See Manual of Patent Examining Procedure (9th ed. Rev. 10.2019) (MPEP) sec. 211.01(b)(I).” (Federal Register/Vol. 88, No. 39/Tuesday, February 28, 2023/Rules and Regulations; Page 12561)

    Updated USPTO Form PTOL-85B (Issue Fee Transmittal) includes a reminder to file any continuing application prior to issue-fee payment so as not to jeopardize co-pendency. The newly modified form can be found here. The form no longer allows for advance orders of patent copies, because patents may be printed directly from Patent Center when issued. Advance orders for copies of patents issuing on or after April 18 will not be processed.

    More information from other insightful publications:

    Ready, Set, Go: Implications of USPTO’s Shift to Electronic Patent Grants (foxrothschild.com)

    eGrants and Quick Issuances | Patently-O (patentlyo.com)

    USPTO ushers in new era with introduction of electronic patent grants | USPTO

    USPTO Transitions to eGrants from Paper Patents | JDSupra

    USPTO To Transition To Electronically Granted Patents In April 2023 | Blogs | PharmaPatents | Foley & Lardner LLP

    Supreme Court Sizes Up the Genus – Enablement

    The Supreme Court of the United States (SCOTUS) is set to hear arguments on Monday, March 27, 2023 for Amgen v. Sanofi.

    ACS’s Chemistry and the Law (CHAL) Division weighs in

    The American Chemical Society’s Chemistry and the Law (CHAL) division filed an Amicus brief supporting Amgen’s petition and reversing the Federal Circuit’s decision. Indeed, the resolute CHAL even petitioned the court to get 5 minutes to participate in arguments.

    Stay Tuned!

    Amgen Inc. v. Sanofi – SCOTUSblog

    Amgen’s X-Ray crystallography studies of antibodies 21B12 & 31H4 bound to PCSK9