Rounding the Bend: Declare Development and the Position of Extrinsic Proof

by Dennis Crouch

Actelion Prescription drugs Ltd v. Mylan Prescription drugs Inc., No. 2022-1889 (Fed. Cir. Nov. 6, 2023) [decision]

The Federal Circuit’s bread-and-butter through the years has been declare constructions that usually shock or confuse district courtroom judges. A part of the problem right here is that almost all Federal Circuit judges have construed hundreds of patents and are deeply immersed within the regulation of declare development — whereas most district courtroom judges see declare development as a small a part of a patent case, which itself is a small a part of their general docket. The opposite a part of the problem, in fact, is that no deference is given to the district courtroom’s declare development on attraction. The following attraction then usually seems like that regulation faculty class the place college students appeared to offer actually good solutions within the Socratic sport, however the professor might by no means resist tweaking — “virtually proper.”

The Actelion case entails a standard scenario the place the patent claims embrace a measurement however don’t state the extent of precision, and the courtroom is pressured to determine whether or not values barely outdoors the claimed vary may be coated.

Actelion’s U.S. Patent Nos. 8,318,802 and eight,598,227 are directed to a brand new formulation of epoprostenol, a substance that naturally happens within the human physique and that’s helpful for treating cardiovascular ailments.  The claims seem directed to a product-by-process — a freeze dried powder (lyophilisate) shaped from an answer that incorporates epoprostenol and that “has a pH of 13 or larger.” Mylan’s ANDA proposes a generic model that will have a pH produced from an answer with pH just below 13.

The query for declare development is whether or not the requirement of “13 or larger” pH encompasses one thing akin to a pH 12.6.  For summary mathematicians, it’s fairly clear that 12.6 is lower than 13 — the other of what’s claimed. However, experimental scientists perceive {that a} measurement of 12.6 may usually be correctly rounded to 13. The district courtroom adopted Actelion’s proposed development that “a pH of 13” consists of values that spherical to 13, similar to 12.5 and concluded that Mylan’s strategy was infringing.  Mylan argued on attraction that the time period requires an pH of “precisely” 13 — not values which might be about or roughly 13.

The Federal Circuit opinion walked by way of numerous elements to assist it perceive the correct development. Because the courtroom has held, the evaluation begins with the declare language, as it’s of main significance. Moreover, “the specification is all the time extremely related to the declare development evaluation” and is  usually “the one greatest information to the which means of a disputed time period.” Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005).

Declare Language: The courtroom examined whether or not the language setting a decrease restrict of “13” precludes rounding or not. The declare is written as an entire quantity, moderately than in decimal type. The district courtroom famous that this concerned “two vital figures’ with out implying any larger degree of precision.”  At oral arguments, the patentee’s counsel defined:

[The inventor] didn’t say 13.0, which is a determine that will have 10 occasions the higher precision, and definitely didn’t say ‘precisely 13’, which isn’t scientifically doable within the context of pH, since you’re speaking about measurement of billions of ions in a liter of water of hydrogen ions and figuring out their focus.

Oral args at 18:00. On the opposite facet, in locations the specification appeared to equate 13.0 to the entire quantity 13.

Lack of Approximation Phrases: The courtroom famous that the declare lacks phrases like “about” that will indicate approximation and which might be usually included inside patent claims. Because the courtroom defined, “In contrast to different declare phrases, the disputed declare time period lacks approximation language like ‘about.’”

Nature of pH Measurements: The courtroom thought-about whether or not pH values will be measured exactly or inherently require some margin of error. The courtroom famous Actelion’s argument that “it’s not virtually doable to measure actual pH values” as a result of it might require counting each hydrogen ion in resolution.

Specification: The specification alternately makes use of approximation phrases like “about” or lacks decimal factors when describing pH values. For instance, the specification states the pH is “ideally adjusted to about 12.5-13.5, most ideally 13.” This reveals the inventor knew the best way to use “about” to indicate approximation, however didn’t for the “13” worth.  The assertion additionally means that 12.5 is totally different from 13.  Because the courtroom summarized, “the specification is inconsistent, additionally describing pH values like ‘13.0’, ‘11.58’, and ’13’ with out clear precision.”

Prosecution Historical past: Throughout patent prosecution, the patentee had distinguished its invention from a formulation with pH 12 — arguing that pH 13 exhibited considerably extra stability. However the prosecution historical past didn’t examine pH 13 with values in between 12 and 13. Because the courtroom defined, the examiner “drew a distinction between the steadiness of a composition with a pH of 13 and that of 12” however this didn’t deal with whether or not pH 13 consists of values rounding to 13.

With declare development, the Federal Circuit has dominated that courts can very often construe claims primarily based solely upon intrinsic proof. However, at occasions courts are permitted to go additional and entry extrinsic proof like scientific texts.  Right here, the Federal Circuit concluded that this can be a case the place extrinsic proof  is critical to know how a talented artisan would view the declare language when it comes to pH precision and vital figures.  Because the courtroom defined, “this case is one the place the correct declare development can’t be reached with out assistance from extrinsic proof.” The appellate panel thus vacated the declare development and infringement judgment and remanded for the district courtroom to think about the extrinsic proof like scientific textbooks and maybe knowledgeable testimony within the technique of reconsidering the declare development.

The panel consisted of Circuit Judges Reyna, Stoll, and Stark. Circuit Decide Stoll authored the opinion.

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This case highlights a difficulty that has led to assert development disputes in quite a few circumstances involving measurements and precision with billions of {dollars} turning on so-called rounding errors. The shortage of readability stems from candidates not specifying the precision or margin of error for declare phrases both within the unique software or throughout prosecution. This ambiguity could possibly be prevented if the USPTO had been to place the onus on patent candidates to determine the precision and error margin for any measurements recited within the claims. For instance, the USPTO examiner might reject the claims as ambiguous primarily based upon the broadest affordable interpretation and require the applicant to make clear whether or not “a pH of 13” permits for values that spherical to 13 and if that’s the case, the appropriate variance (e.g. ± 0.1, ± 0.01 pH items).

Requiring patent candidates to explicitly determine the precision and error margin for measurements throughout prosecution would stop the necessity for courts to resort to extrinsic proof to resolve ambiguity that ought to have been addressed earlier than issuance. This may enhance certainty round declare scope and cut back pointless litigation.

What do you suppose, ought to the USPTO think about extra methods to have candidates make clear declare time period precision when submitting and prosecuting purposes involving numerical measurements?