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2023 Patent Review 

Another year has come and gone, and patent law has been chiseled and defined ever so slightly by another year of court decisions. I’ve combed through a number of these decisions and summarized five for your reading pleasure. Are these the best patent cases of 2023? Is “Stairway to Heaven” Led Zeppelin’s best song? It all depends on what you like. Either way, the five cases below are all noteworthy as demonstrating how our nation’s highest courts are dealing with unending complexities in a range of patent topics.

The cases I’ve chosen tend to address one or more of the big five topics in the eligibility or patentability of a patent application – eligible subject matter, usefulness, novelty, non-obviousness, and a proper specification. These issues are all statutorily defined in the United States Code, 35 U.S.C. §§ 101, 102, 103, and 112. But how do you define the definitions? And how do they work in practice? The answers to these questions continue to grow and evolve, now more than 70 years after the codification of the Patent Act of 1952.


Amgen Inc. v. Sanofi, 598 U.S. 594 (2023)



What does it mean for a patent to “enable” someone to “make and use” an invention?

Facts of the Case

Biopharmaceutical giant Amgen Inc. owns several patents on cholesterol-lowering drugs. The claims to one of these patents described the antibodies used to treat high cholesterol according to their function of “binding” with certain proteins. The patent’s written description listed 26 such antibodies as examples, but it also included methods of identifying other antibodies that would fall under the scope of the patent based on the language in the claims.

Amgen sued Sanofi for infringement of the patent covering the antibody functionality. Sanofi argued the Amgen patent was invalid for failing the enablement requirement of US patent law in 35 U.S.C. § 112(a). Section 112(a) states that a patent’s specification must be descriptive enough to “enable any person skilled in the art . . . to make and use” the claimed invention.

The Delaware court found the patent invalid on its second pass at the case, after a remand from the US Court of Appeals due to erroneous jury instructions. Amgen then appealed to the Federal Circuit, which affirmed the lower court’s finding that the scope of the generic claims to the antibodies was not adequately enabling. Amgen then appealed to the US Supreme Court.


In a unanimous decision, the Supreme Court affirmed the Federal Circuit’s decision that the Amgen patent was invalid. Despite listing only 26 different embodiments of antibodies, the scope of the claims was so expansive that a class of “potentially millions of antibodies” could fall into Amgen’s lap.

A patent that claims an entire class must enable a person skilled in the art to make and use that entire class. While a reasonable amount of experimentation is permitted, it cannot be too broad. Here, the scope of the patent claims would allow Amgen to monopolize an entire class of antibodies, but Amgen only describes 26 antibodies by their amino acid sequence. Simply put, the scope of potential protection was not commensurate with the patent’s disclosure. “[E]ven allowing for a reasonable degree of experimentation,” Justice Gorsuch wrote, “Amgen failed to enable all that it has claimed.”

Amgen argued that its methods for identifying other antibodies was a “roadmap” sufficient to satisfy enablement of any antibodies beyond those 26 described in the patent. The nine Justices disagreed, noting that the “trial and error” nature of those methods would amount to “painstaking” undue experimentation and thus were not enabling.

Why does this matter?

“The more one claims, the more one must enable” ­– Page 594 of the Opinion.

The enablement requirement exists as part of the quid pro quo nature of a patent. That is, in return for getting an exclusive right over an invention, the inventor must disclose to the public how the invention works. Teaching inventions to others incentivizes further invention and thus perpetuates the goal of constant progress and innovation. Because Amgen’s patent failed to adequately describe its invention, the public could not use it to drive future innovation. Amgen was not holding up its end of the bargain. This is consistent with the current trend of preventing patentees from monopolizing a field. The courts are favoring more focused patent disclosures, ensuring that there is still room for competition and advancement by the public.

If a patent applicant does want broad protection over an entire field, or an entire class of antibodies, that window is not completely closed. The Amgen result only means that the applicant must fully disclose each antibody when, in the past, she could simply disclose a few representative examples (as Amgen tried in this case). This heightened scrutiny means a lot more time, effort, and money on the part of the applicant who, without the deepest of pockets, may just not have the resources. This leaves Amgen, as an example, vulnerable to other innovators entering the space – because each disclosure must have a more defined scope, competitors can more easily obtain patent protection over very similar antibodies without infringing the 26 antibodies in Amgen patent.

It has been suggested that limiting the enabled scope of an invention will also cut down on applications being rejected for novelty and obviousness. For example, a patentee could file multiple applications over similar areas without risking obviousness because the scope of enablement in each application is more focused, rather than being broad enough to encompass everything. I’m not particularly sold on this forecast, but it will be interesting to watch in the coming years.


Salazar v. AT&T Mobility LLC, 64 F.4th 1311 (Fed. Cir. 2023)



When you claim “a” thing, how many of “said” thing are you claiming?

Facts of the Case

Ms. Salazar sued AT&T and other carriers over their use of the HTC One phone, which allegedly infringed an expired patent to Salazar. The Texas federal District Court found that Salazar’s patent was not invalid and that there was no infringement by the wireless carriers. The parties then cross-appealed to the US Court of Appeals for the Federal Circuit. Salazar again alleged patent infringement, while the Defendants alleged that Salazar’s patent was invalid based on its claim construction. We’re focusing here on the claim construction portion of the appeal.

The dispute revolved around whether the term “a microprocessor” required only a single microprocessor for performing the recited functions. Claim 1 of Salazar’s patent describes a communications system “comprising a microprocessor.” Claim 1 continues, also comprising a memory device, interface, and frequency transceiver that are all “coupled with said microprocessor.” Claims using the term “comprising” are considered open-ended, meaning the invention contains at least everything listed in the claims. In open-ended claims, courts generally construe the article “a” as meaning “one or more.” Furthermore, subsequent use of “said” to refer back to the same term reinvokes the nonsingular meaning of the article. The federal District Court followed that rule, thus finding that the claim did not limit the invention to having only a single microprocessor.


The Federal Circuit affirmed the lower court’s holding, construing the claim to mean “one or more microprocessors, at least one of which is configured to perform the generating, creating, retrieving, and generating functions.” The Court followed prior precedent for determining whether a claim refers to using one item to perform a list of functions, or to using any number of items to perform the listed functions.

Without going too deep, the analysis essentially comes down to whether the claim, specification, or prosecution history necessitates “a” to mean “one and only one.” Otherwise, the article will be construed to mean “one or more.” Here, Salazar repeatedly used “said microprocessor” throughout Claim 1’s limitations to refer to “a microprocessor” introduced at the start of the claim. The language of those limitations required “said microprocessor” to mean at least one microprocessor capable of performing each claimed function. Thus, the article “a” in Salazar’s patent claims retained its nonsingular meaning.

Why does this matter?

A proper specification must include claims “particularly pointing out and distinctly claiming” the invention. (35 U.S.C. § 112(b)). Inventors can fail this requirement in a number of ways, like failing to use proper “antecedent basis” for claim terms. Antecedent basis means that a claim must introduce a term before you can use it to explain your invention. For example, you cannot claim “a wheelbarrow that moves using the wheel” unless you have already claimed “a wheelbarrow comprising a wheel.”

As you draft your claims, remember that you earn the most patent protection by keeping your claims as broad as possible based on the prior art. Though you may satisfy the antecedent basis requirement, using “a” or “said” in a way that suggests your term to be singular could present two problems: First, you could overly narrow your claims. That is, if your claim covers only one microprocessor, a competitor could potentially patent around it by claiming a similar invention with the multiple microprocessors you intended to claim. Second, you risk claiming something that does not match what you invented. That is, if your invention always uses multiple microprocessors but your claims limit it to just one microprocessor, then your patent does not protect your invention (this was AT&T’s assertion here).

The Salazar case did not change patent law, but it reintroduced an important consideration to keep in mind while drafting claims. The lesson here is not really to remember to use antecedent basis; rather, it is to use it wisely. If you don’t want to claim something as singular, then avoid using singular terms. Use “one or more” or “at least one” instead. Furthermore, make sure that your specification supports and clarifies what you’ve claimed. If you do claim “a microprocessor,” use your specification to explain that any term written in the singular may include its plural version.


Hip, Inc. v. Hormel Foods Corp., 66 F.4th 1346 (Fed. Cir. 2023)



How much must you contribute to an invention to be considered a joint inventor?

Facts of the Case

Food-processing company Hormel owns a 2018 patent directed to a hybrid baking cooking system. In 2007, Hormel entered into a joint agreement with HIP, Inc., to develop an oven for a two-step cooking process. During this partnership, HIP representative David Howard disclosed an infrared preheating concept. Hormel filed a patent application in 2011, and the issued patent did not list Howard as an inventor.

Howard sued Hormel, alleging that he should be included on the patent as a joint inventor. The US District Court for the District of Delaware agreed, noting that independent claim 5 described preheating meat using a method selected from “a microwave oven, an infrared oven, and hot air.” Hormel’s inventors also admitted that they did not conceive of the infrared preheating limitation. Hormel appealed the decision, arguing that Howard’s contribution was too insignificant to merit inclusion as a joint inventor.


On appeal, the federal District Court’s holding was reversed. The Federal Circuit’s analysis relied on the high standard of the Pannu test, which requires one to satisfy three elements to qualify as a joint inventor. The Pannu elements stipulate that a joint inventor must have (1) contributed in some significant manner to the conception of the invention, (2) contributed to the claimed invention that is not insignificant in quality, when measured against the dimension of the full invention; and (3) did more than merely explain to the actual inventors some well-known concepts and/or the current state of the art.

The Court looked at the drawings, specification, and claims of the Hormel patent, and found that the second Pannu element destroyed Howard’s case. The drawings depict Hormel’s microwave ovens throughout, while not once describing Howard’s infrared oven. The specification mentions Howard’s contribution only once “as an alternative,” while focusing on the Hormel ovens. Similarly, the claims mention the infrared oven only once and in a single claim, while otherwise focusing on the microwave oven. Thus, based on the scope of the patented invention, Howard’s contribution was insignificant and he did not qualify as a joint inventor.

Why does this matter?

“To qualify as a joint inventor, a person must make a significant contribution to the invention as claimed.” – Page 1350 of the Opinion.

Inventorship is often discussed as a low standard, simply requiring that one contribute to conception in some way. That threshold is unchanged, but in reality, it is only enough to justify why someone could include you as a joint inventor. The Hip case shows us that, if you are left off the inventor list, justifying why you must be included is a much taller task.

The correction of named inventors in an issued patent is covered in 35 U.S.C. § 256, which requires proof of facts and “other requirements.” Hip is a good example of the fact-based inquiry the courts use to decide whether you made significant enough contributions to warrant a correction of inventorship.


Axonics, Inc. v. Medtronic, Inc., 73 F.4th 950 (Fed. Cir. 2023)



When deciding whether an invention is “obvious,” what is the proper way to analyze whether one would be motivated to combine existing patents to make that invention?

Facts of the Case

Medical device company Medtronic, Inc., owns two patents that describe and claim a neurostimulation lead and a method for using it. Medtronic sued med-tech company Axonics for infringement of the two patents. Axonics responded by initiating inter partes review (IPR) against each patent. IPR is a proceeding brought before the Patent Trial and Appeal Board (PTAB) by a party challenging an issued patent on limited grounds. Here, Axonics asserted that various claims in the Medtronic patents rendered them obvious, and therefore unpatentable, based on two existing patents (Young and Gerber).

The PTAB decided in favor of Medtronic in both IPR proceedings, concluding that Axonics failed to prove any of the claims at issue were unpatentable. Basically, the reasoning was as follows: Young involved a lead for stimulating the trigeminal nerve. The Medtronic patents, though not specifically limited to trigeminal nerve stimulation, were broad enough to cover it. The sacral nerve lead of Gerber, however, addresses a different problem, and would not work for trigeminal nerve stimulation due to anatomical considerations. Therefore, a person skilled in the relevant art would not have been motivated to combine Young and Gerber. Dissatisfied, Axonics appealed to the US Court of Appeals for the Federal Circuit.


In a precedential decision, the Federal Circuit vacated and remanded PTAB’s ruling. The Federal Circuit’s decision was based on two errors committed by PTAB. Because those errors could not be considered “harmless,” the Court had to vacate the PTAB’s holding.

First, PTAB incorrectly implemented the “motivation-to-combine” question in its obviousness analysis. As described above, PTAB found that there was no motivation to combine Gerber with Young based on Young’s focus on trigeminal nerve stimulation. That is, PTAB analyzed the motivation to combine the prior art based on a purpose described in the prior art. The proper inquiry should have been the motivation to combine Young and Gerber based on the claimed inventions in the Medtronic patents.

Second, PTAB limited its definition of relevant prior art as that relating to leads used for sacral nerve stimulation. This narrowing was improper because the Medtronic claims neither referenced nor limited their scope to sacral stimulation. Although, for example, one Medtronic patent stated a goal of addressing an “implantable electrical sacral nerve stimulation lead,” the written description also permitted a much broader scope for the invention. Thus, PTAB failed to compare the prior art based on the true, broader scope of the Medtronic patents.

Why does this matter?

The proper motivation-to-combine inquiry is whether “a skilled artisan would have been motivated to combine the teachings of the prior art references to achieve the claimed invention.” – Page 957 of the Opinion, quoting Allied Erecting & Dismantling Co. v. Genesis Attachments, LLC, 825 F.3d 1373, 1381 (Fed. Cir. 2016) (emphasis added by the Federal Circuit).

No matter the outcome on remand, the Federal Circuit’s decision prevents PTAB from excessively narrowing the scope of a motivation-to-combine inquiry. This is not a favorable result for patentees, as a broader inquiry leaves more inventions at risk of being deemed obvious. The ruling also does not overtly provide patent applicants with new guidance on how to draft their applications to avoid obviousness. Rather, it clarifies the standards by which PTAB operates in determining obviousness. With that in mind, however, patentees (like Medtronic) and challengers (like Axonics) are both better equipped to understand how prior art might be considered in an obviousness analysis. Perhaps, then, both sides will more readily recognize when a patent might be vulnerable to such a challenge.


Minerva Surgical, Inc. v. Hologic, Inc., 59 F.4th 1371 (Fed. Cir. 2023)



What can cause a patent to be invalidated due to “public use” that occurred before filing the patent application?

Facts of the Case

Medical manufacturer Minerva Surgical obtained a patent over a device for endometrial ablation in 2015, and the patent had a priority filing date of 2011. Years later, Minerva sued med-tech companies Hologic, Inc. and Cytyc Surgical Products, LLC, for infringement of its device. The Defendants moved for summary judgment, asserting that the patent claim at issue was invalid under the public use bar of 35 U.S.C. § 102(b). Section 102(b) says an inventor is not entitled to a patent over an invention that was previously described, publicly used, or offered for sale in the US more than one year before filing a patent application. (This is the “pre-AIA” version of § 102(b). The America Invents Act (AIA) considerably altered how patent law operated after March 2013, but the pre-AIA law is still applied to patents and applications with filing dates prior to that date. The equivalent provision under AIA law is § 102(a)(1).)

This “public use” occurred in late 2009, two years prior to filing the application, when Minerva brought a prototype of its device to a large conference and trade show. At the trade show, Minerva representatives demonstrated the fully functional device to attendees, gave a presentation on its capabilities, and handed out brochures detailing the device’s construction. Also of note, Minerva did not impose any secrecy obligations on the attendees of the event, who were able to closely observe the device.

The US District Court of Delaware agreed with the Defendants that this 2009 conduct invalidated the Minerva patent, filed two years later, under the § 102(b) public use bar. Minerva appealed.


The US Court of Appeals for the Federal Circuit affirmed the lower court’s summary judgment. The public use or sale date of section 102(b) is triggered when an invention is both (1) in public use, and (2) ready for patenting. This is termed the “critical date.”

A device is “in public use” when it is accessible to the public or commercially exploited by the inventor. Here, Minerva’s myriad exploitation of the device during the 2009 event easily satisfied this first element. A device is “ready for patenting” where there is either enabling documentation of the claimed invention or a reduction to practice of the invention before the critical date. Here, Minerva’s prototype was fully functioning, and the brochures detailed the technical specifications of the device. This satisfied the second element.

Why does this matter?

Your own invention can potentially stop you from patenting it. It’s exciting to bring your creation to a trade show and show the world how innovative you are, but don’t let that demolish your chances at patent protection. Proper confidentiality and non-disclosure agreements can also be effective in preventing your actions from triggering that critical date under 35 U.S.C. 102.

  • Public Use:

The Federal Circuit in this case reiterated that “public use” does not require the public to actually use the invention. Rather, merely making the ready-for-patenting device “accessible to the public” can be enough. The Federal Circuit also distinguished the present case from prior decisions that required actual use, namely its 2007 Motionless Keyboard decision. The court in Motionless found there was no public use where the claimed keyboard was never connected to be used at the trade show and was only virtually displayed. In addition to Minerva physically demonstrating its device at its event, the use permitted close observation by attendees who were sophisticated in the industry. This went “well beyond” the level of “mere display” in Motionless.

  • Ready for Patenting:

Inventors cannot relax just because their prototype has not actually been used in its intended environment; lab studies can be enough. Similarly, the fact that you might tinker with portions of your invention later on does not negate the fact that previous iterations were ready for patenting.

If you’re reading this and alarms are going off in your head, we advise you to seek legal counsel. The team at Rockridge  can not only help you understand your situation but guide you in a direction to protect your patent rights as much as possible. Read more Rockridge insights on patents here.


About Logan Ray

An image to depict Logan Ray, the author of the article

Logan is a registered patent attorney at Rockridge®, a Certified B Corp and RealLeaders Top 150 global impact company. Logan previously worked at the University of Cincinnati Tech Transfer Office and the IP team at Angiodynamics, a New York-based company specializing in medical devices used to treat cancers and vascular diseases. Prior to law school, Logan spent nearly a decade as a registered dental hygienist.

Practice Areas

Logan’s practice areas include:

  • patent and trademark prosecution, licensing and litigation;
  • corporate law, with an emphasis on benefit corporations, socially responsible businesses and high-growth emergent companies;
  • government contracts, with an emphasis on innovation funding;
  • corporate and investor financing; and,
  • technology commercialization.


Email Logan Ray directly at

Logan Ray

Author Logan Ray

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