by Dennis Crouch
I previously wrote about Allergan USA, Inc. v. MSN Laboratories Private Ltd. (Sun Pharma), No. 24-1061 (Fed. Cir. Aug. 13, 2024), focusing on Federal Circuit’s about-face on obviousness-type double patenting. My original post skipped over an important aspect of the opinion: the court’s 2-1 decision favoring the patentee on the written description requirement of 35 U.S.C. § 112(a). This portion of the case focuses once again on when an element is “essential” to the invention and therefore required in the claims.
Four key takeaways:
- We presume that no element is “essential.”
- Courts should look for indications in the patent documents that the feature is critical, essential, etc.
- The court here relied upon broad claims in the priority filing that were later deleted in order to show the inventor possessed embodiments that did not require the element.
- The key focus for written description is comparing the specification with the claims. Although expert testimony may be relevant, it must be directly tied to the intrinsic record.
All of these elements point to the idea that it is the job of the patent drafter and prosecutor to ensure the written description is sufficient, and to avoid pitfalls that might indicate otherwise.
Family Planning Patent Style: Allergan, Cellect, and the ODP Maze
Allergan’s patents cover fomulations of Allergan’s irritable bowel syndrome drug Viberzi (eluxadoline). The specifications describe particular tablet formulations, with each embodiment including a “glidant” used to improve the flow properties of powder mixtures during the manufacturing process to ensure consistent tablet weight and uniformity. Examples of glidants include colloidal silicon dioxide, talc, and magnesium stearate.
All embodiments and working examples in the specification included glidants, and the original claims in the patent family also included a glidant. However, the asserted claims do not require the glidant. At oral arguments in the Federal Circuit appeal, Charles Klein, counsel for the accused infringers explained:
What happened here is the original claims from this patent family mirrored the specification. And then during litigation, after plaintiffs learned that Sun’s product didn’t use one of the ingredients [the glidant], plaintiffs went to the patent office and then took an ingredient out of the patent claim to try to capture Sun’s product.
Oral arguments at 17:40. Delaware District Court Judge Richard Andrews had invalidated these claims for lack of written description support, finding a mismatch between the disclosure and the claims. In particular, Judge Andrews found that the claims covered tablets with or without the glidant, but that the specification only demonstrated possession of formulations lacking a glidant. On appeal, the Federal Circuit reversed in a split decision, with Judge Dyk dissenting.
Prototypical written description cases involve a genus-species relationship between the specification and claims. In other words, we typically have a narrow disclosure of an invention followed by a broad genus claim. A classic example of this is seen in Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., 598 F.3d 1336 (Fed. Cir. 2010). In Ariad, the specification disclosed a few specific molecules that could reduce NF-κB activity, but the claims were directed to a broader genus of methods of reducing NF-κB activity in cells. The Federal Circuit found that this broad functional claim limitation lacked adequate written description support because the specification did not disclose a representative number of species or structural features common to the genus.
The omitted element situation, as seen in Allergan, adds a trickster layer because the broad genus is not expressly claimed. Rather, the genus is implicitly provided by omitting the species limitation (in this case, the glidant) from the claim and relying upon the open-ended “comprising” transition phrase to ensure broad claim breadth with or without the glidant.
Consideration of omitted elements presents a logical difficulty because the process often lacks a limiting theory. Although the specification must convey possession of the full scope of the claimed invention, that can seem impossible for a typical patent claim using the open “comprising” transition phrase. “Comprising” is open-ended and indicates that the claim scope includes the stated elements along with all possible omitted elements, and it would be impossible show possession of those myriad unnamed elements. This issue has been a continual challenge for jurists seeking to balance the inherent breadth of “comprising” claims against requirement that the specification convey possession of the full scope of the claimed invention.
The majority opinion, authored by Judge Lourie and joined by Judge Reyna, emphasized that this was “not a typical written description case.” Unlike many written description disputes involving broad genus claims supported only by limited species examples, here the claims at issue were “essentially picture claims to a particular pharmaceutical tablet comprising eluxadoline and various inert ingredients.” The majority noted that the claims recited specific ingredients and amounts, not broad classes of excipients. Moreover, it was “undisputed that each of the claimed limitations, i.e., each of the expressly recited ingredients and its recited amount, is adequately disclosed in the specification.” The majority also reiterated that the focus here is on “whatever is now claimed.” (quoting Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555 (Fed. Cir. 1991)).
Applying these principles, the majority found clear error in the district court’s conclusion that the specification failed to demonstrate possession of a formulation without a glidant. The court pointed to two embodiments in the specification that did not expressly require a glidant. The court went on to reject the notion that that the specification needed an express statement that a glidant was optional.
Look to the Priority Document: The majority also looked back to an original claim in the priority application that did not expressly require a glidant. The court cited In re Gardner, 480 F.2d 879 (CCPA 1973), for the proposition that originally filed claims are part of the specification. The accused infringer had argued that this original broad claim was worthless – immediately rejected as obvious and never recovered. However, the Federal Circuit seemed to conclude that the doctrine was satisfied by its existence. I’ll note here that I am not entirely familiar with the bounds on this doctrine regarding the idea that statements in the parent filings count toward written description of the child, even if never included in the child.
Look to the Importance: In thinking about essential elements, the court also noted that the stated importance of the limitation should be considered. Here, the Allergan patents mentioned a glidant, but did not explain any substantial function or significance associated with its addition. This is contrasted with ICU Medical, Inc. v. Alaris Medical Systems, Inc., 558 F.3d 1368 (Fed. Cir. 2009), where the court held that valve “spikes” were an essential unclaimed element. In that case, the patentee had repeatedly described the spikes as as necessary for piercing a seal.
As to How to Prove Written Description: The district court had emphasized its reliance on expert testimony. Here, however, the Federal Circuit pushed for an internal inquiry — “the specification first” then with nuance added by expert testimony. “Reliance on such testimony, untethered to the inventors’ own description of the invention, would improperly take the written description inquiry outside the four corners of the specification.”
Utility, Enablement and WD: The majority opinion concludes with a “final cautionary point.” The court explains that operability of a claimed invention should primarily be considered under the utility and enablement doctrines, not written description. Applying that here, the court explained that “although a formulation without a glidant may not flow as well as a formulation with a glidant, that does not mean that the formulation would not ‘work’ without a glidant, as the district court found.”
Judge Dyk dissented — viewing the case as “quite similar” to ICU Medical and arguing that Allergan had improperly attempted to broaden its claims by removing a limitation present in every disclosed embodiment. Judge Dyk emphasized the expert testimony indicating that a person of ordinary skill would normally use a glidant and would interpret the specification as showing possession only of formulations including a glidant. This was the approach taken by Sun’s counsel who emphasized the importance of the district court’s factual findings: “Judge Andrews heard the battle of the experts on whether a Glidant was always optional and ruled in our favor. And there’s no basis to find clear error.”
= = =
This seems to me to be another example of defense attorneys convincing a trial court judge to issue a favorable decision on a legal technicality [involving a common medically-inactive mere filler in a drug pill at that] which was highly likely to get a Fed. Cir. appeal reversal, as here. The case will now go back to that same judge, who is not going to be pleased with the defendant’s attorneys for having lead him down that strongly-reversed-decision path. Especially if the judge was lead into factual errors as well. That is not likely to be helpful to defendent in its further defenses or damages disputes. That is not a trial court victory.
It strikes me that the WD test “in possession of” the claimed subject matter leaves open the possibility for a drafter/patent applicant to begin with narrow claims and then, in a succession of continuations, step-wise ratchet out the scope being claimed, in each succeeding continuation, arguing each time that they were, from the get go, truly in possession of the subject matter of the current wider claim. How shall one write useful FTO opinions, in such an environment?
Is this a good way to promote technological progress?
Given that two of the Worked Examples did not use a glidant, how did it come to pass that a glidant was, from the get go, recited as an essential feature of the subject invention in all of the claims appended to that specification. Was that a claim-drafting accident? Or was it deliberate?
Does the USPTO examine for consistency between what the claims define as the invention and what the specification describes as the invention? The EPO does, painstakingly. Is the EPO wasting its time, and that of the applicant? Or is it a good idea to require consistency between specification and claims, before letting the application through to issue?
🙂 I’d based my quip below on this statement from Professor’s article:
“All embodiments and working examples in the specification included glidants, and the original claims in the patent family also included a glidant. However, the asserted claims do not require the glidant. ”
Your writing above suggest two of the examples did not use a glidant ? so this is at odds with Prof.’s statement.
Preferably, inerts are recited in some late dependent claims, like claim 47 or something. I always strive to have congruency btw spec and claims, particularly where working examples are concerned, preference being to coax my inventors to concoct working examples featuring specific values at each end of the claimed range, and so on.
We also have this in the MPEP 2164.01:
“A patent need not teach, and preferably omits, what is well known in the art. ”
If one had a claim with open-ended “comprising” language but omitted inerts, the comprising language should include formulations having any inert one might select, if appropriate language is in spec and perhaps citation incorporation by reference of Trade Handbook listing all known inerts used in Pharma compositions.
Dennis notes in his post that the court noted that two of the Examples did not expressly require a glidant. I was relying on that statement.
Two items:
1) the narrow to begin and then widen is a well known and oft used tactic;
2) how can one know? Easy – if the family is alive, then pretty much anything that may be claimed in the original filing should likely be considered to, well, be able to be claimed.
Yes, given the large number of continuations that Dennis asserts, plus many divisionals, a U.S. right-to-use opinion needs a full family search AND caviats or disclaimers. Even more so if defects in one patent have been pointed out by lawsuit defendants while continuations are pending in which claim amendments can be made, and additional prior art cited.
first question to me was: why there was no “new matter” rejection when patentee went to remove the glidant from the claims? Maybe the Examiner wrongly thought there was support in the spec for applicant to remove glidant from the claims. Or the Ex forgot that sometimes deleting words can constitute new matter. Had the Examiner made a “new matter” rejection when those words were deleted from the claims, would it have been proper ? If so, that would have been a better time to handle the issue and not let this become a time drag on everyone.
My thoughts entirely. But as I write from Europe, I thought I had better stay silent on the subject of “added matter”.
But now you’ve raised it, I thought the patent family might be revealing. One glance at its bulk though scared me off.
Even at the EPO there is, given the facts as summarised by Dennis, an argument that the widening of the claim did not add matter.
Meh – as long as you can recognize that both Sovereigns have A “no new matter” edict, and remember that the US does not require ipsis verbis as well as is far more lenient on intermediate generalizations, you should be good.
I had never seen a U.S. PTO examiner “new matter” rejection of after-filing broadened application CLAIMS [and rare 112 rejections outside of chemical practice]. Rare even for Specification changes, or even detected.
Have others?