Does the Limit Exist?: Negative Limitations in Novartis v. Accord

In an appeal, Novartis Pharmaceuticals v. Accord Healthcare, Inc., the issue of whether a patent provides sufficient written description of a negative limitation[i] split the panel at the Federal Circuit. Novartis Pharmaceuticals v. Accord Healthcare, Inc., Appeal No. 2021-1070, at *2 (Fed. Cir. Jan. 3, 2022). The case began at the District Court of Delaware with a bench trial that ultimately found HEC Pharm Co., Ltd. and HEC Pharm USA Inc. (“HEC”)’s ANDA to infringe Novartis’s valid ’405 patent. At the Federal Circuit, the majority opinion, drafted by Judge O’Malley, affirmed the lower court’s findings, i.e., the patent’s negative limitation was supported and thus valid, because there was no clear error[ii].

A. Majority Opinion, drafted by Judge O’Malley

To determine the scope and written description of the negative limitation “at a daily dosage of 0.5 mg without an immediately preceding loading dose” (’405 patent col. 12 ll. 49–55) the court looked at both the ’405 patent and 2006 priority patent specifications. In doing so, the majority found written description for this negative limitation by holding that both specifications identified fingolimod hydrochloride, described the results of an experiment where rats suffered a disease that mimics relapsing remitting multiple sclerosis (RRMS or MS), discussed a prophetic human clinical trial, and described a wide range of potential dosages.

1. 0.5 mg daily human dose limitation was possessed by the inventor

The majority decided that the evidence demonstrated the 0.5 mg daily dose of fingolimod limitation was possessed by the inventor as of the 2006 priority date. First, two expert witnesses put forth by the patent owner explained the leap from the 0.3 mg/kg weekly rat dosage to the 0.5 mg daily dosage limitation. Second, the clinical trial disclosed dosing RRMS patients at that daily dosage. But the animal experiment did not disclose in haec verba this limitation. The majority found that relying on expert testimony to find the description of this limitation in the experiment’s results was proper because it could not “ignore the perspective of the person of ordinary skill in the art.” Such a person would recognize that Novartis invented what was claimed.

HEC had argued that the wide range of potential dosages in the ’405 patent lacked the necessary “blaze marks” that would direct a skilled artisan to the “claimed species from among a forest of disclosed opinions…” The majority disagreed that such marks were needed in this patent because the daily dosage could be found in the clinical trial and was the starting point of the daily range disclosed in the specification.

2. But was a loading dose limitation missing, and thus not supported?

What was missing from both specifications? A loading dose. It is undisputed that neither the animal experiment or clinical trial described in the specification recite a loading dose. Both parties’ experts even agreed on the definition of the disputed term: a higher than daily dose that is “usually given as the first dose.” But what was also undisputed is that loading doses were well known in the medial field and prior art in connection with MS.

The district court found that the patent describes alternate dosing regimens, but not administering those regimens with a loading dose; therefore, a skilled artisan would believe that the invention did not include the administration of a loading dose. Yet Novartis’s three experts testified that one would expect that if a loading dose were in the patent, it would be specified. HEC’s own expert agreed that the loading dose is usually given as the first dose. Thus, the district court found the patent provides sufficient written description of the negative limitation. The Federal Circuit found no clear error in this finding.

The majority decision summarizes Federal Circuit precedent regarding negative limitations to reiterate that negative claim limitations are adequately supported when the specification describes a reason to exclude it – although the law does not require the specification to provide a reason.[iii] The majority held it is enough that the specification properly describes alternative features of the patented invention. Interestingly, the Court explained that a granted patent is presumed (1) valid and (2) to have a complete written description. Although a negative limitation that is inconsistent with the disclosure is not always adequately described.

Therefore, what is “critical” in the analysis of whether the negative limitation exists is the context, knowledge, and common sense of the skilled artisan – not the exact words used in the specification: a negative limitation “must be accompanied by an original disclosure which conveys to a person of ordinary skill that the inventor was in possession of the claimed invention.”[iv]

B. Dissenting Opinion, authored by Chief Judge Moore

To the dissent, “[s]ilence is not disclosure.” The dissent highlights the Patent Office’s MPEP (Manual of Patent Examining Procedure) and the Federal Circuit’s precedent to reiterate that silence cannot support a negative limitation. If the specification is silent, there is no evidence that the inventor actually possessed the invention. This principle is a written description requirement. To allow a silent disclosure to exclude a later-added negative limitation is a “fundamental error of law.”

What else is missing from the patent? Judge Moore found there was more missing from the specification than just “a loading dose.” Language that a loading dose should not be administered, alternatives, advantages or disadvantages of a loading dose, or even a reason to exclude a loading dose are also notably absent. The record does show that, to some degree, both parties’ experts agree that loading doses are sometimes given to MS patients.

The dissent calls out the majority’s “false and inaccurate quotation,” disagreeing with the characterization that the clinical trial as described in the specification discloses an initial 0.5 mg daily dose – the first limitation discussed in this article. The word ‘initially,’ the dissent clarifies, “is basic English” and ‘daily’ has no special meaning in pharmacology. With the addition of this limitation, (1) Novartis “backdoors a claim construction argument,” (2) the district court has rewritten the specification with expert testimony, and (3) the majority opinion “teases an entirely new claim limitation out of an entirely common term.”

Lastly, the dissent does not agree that an issued patent is presumed to have a complete written description. Instead, the validity presumption means that the granted patent complies with the written description requirement – the term ‘complete’ is missing. Such a holding now permits negative limitations to be supported by a specification that simply never mentions them.

C. Conclusion

The law surrounding negative limitation, and especially their relationship to the written description requirement, continues to build at the Federal Circuit and this appeal indicates strong views amongst the judges. At a minimum, this opinion shows how adding a negative limitation to a claim during prosecution can implicate the written description requirement. It also brings a heightened importance to factors such as what a skilled artisan would understand from reading the patent, weight of expert testimony, knowledge and information regarding a skilled artisan’s common sense, and what implicit or inherent disclosures were made.

[i] Novartis’s ’405 patent claims are directed to a 0.5 mg daily dose of fingolimod hydrochloride under the brand name, Gilenya, which treats remitting multiple sclerosis (“RRMS”); the patent claims priority to a British patent filed in 2006.

[ii] The clear error standard means that the appellate court will not overturn the factual findings for written description unless there is a “definite and firm conviction” that a mistake was made.

[iii] Inphi Corp. v. Netlist, Inc., 805 F.3d 1350, 1356 (Fed. Cir. 2015) (there is no “new and heightened standard for negative claim limitations.”); Santarus, Inc. v. Par Pharmaceutical, Inc., 694 F.3d 1344, 1350–51 (Fed. Cir. 2012) (expert testimony properly provided a personal of ordinary skill’s understanding of the patent specification); Nike, Inc. v. Adidas AG, 812 F.3d 1326, 1348 (Fed. Cir. 2016) (finding that negative limitations are held to the customary standard for the written description requirement); All Dental Prodx, LLC v. Advantage Dental Prod., Inc., 309 F.3d 774, 779 (Fed. Cir. 2002) (“[T]he failure of the specification to specifically mention a limitation that later appears in the claims is not a fatal one when one skilled in the art would recognize upon reading the specification that the new language reflects what the specification shows has been invented.”).

[iv] Novartis Pharmaceuticals v. Accord Healthcare, Inc., Appeal No. 2021-1070, at *18 (Fed. Cir. Jan. 3, 2022).

This article appeared in the January 2022 issue of PTAB Strategies and Insights. To view our past issues, as well as other firm newsletters, please click here.