In Titanium Metals Corp. v. Banner[1], the Federal Circuit notably held that it is “an elementary principle of patent law” that when a claim recites a numerical range, the claimed range is anticipated by a prior art reference that discloses a point or an example within that range. Accordingly, when seeking to anticipate a recited range of a claim, both petitioners and patent examiners have often attempted to rely on a reference that discloses a broader range that overlaps the claimed range and contend that overlapping range falls within the recited range, thereby anticipating the claim.

However, a reference, which simply discloses a broader, overlapping range without providing any specific examples that fall within the recited range, may not necessarily anticipate the claim. The prior art reference must disclose the numerical range with “sufficient specificity such that a reasonable fact finder could conclude that there is no reasonable difference in how the invention operates over the ranges.”[2] In other words, a case-by-case determination must be made to determine whether the broader, overlapping range disclosed in the prior art anticipates a narrower range recited in the claim.

The recent final written decision in Koios Pharm. LLC v. Medac Gesellschaft Fur Klinische Spezialpraparate MBH, Case IPR2016-01370 Paper 54 (Feb. 7, 2018) provides further guidance in determining whether a claimed range is disclosed “with sufficient specificity” to constitute an anticipation of the claim. In Koios, the patent at issue was U.S. Patent No. 8,664,231 (“the ’231 patent”), which relates to a method for treating inflammatory autoimmune disease, such as rheumatoid arthritis. Claim 1 of the ’231 patent recites:

A method for the treatment of inflammatory autoimmune diseases in a patient in need thereof, comprising subcutaneously administering to said patient a medicament comprising methotrexate in a pharmaceutically acceptable solvent at a concentration of more than 30 mg/ml.

The Board instituted review on several grounds, including that claim 1 was anticipated by U.S. Patent No. 6,544,504 (“Grint”).

Grint describes treating autoimmune diseases by administering a combination of interleukin 10 and methotrexate, either together in a single composition or separately. Grint discloses that an effective amount of methotrexate may range from 0.01 to 400 mg in a pharmaceutically acceptable carrier. In addition, Grint presents a study evaluating the administration of interleukin-10 and methotrexate to patients, and in that study, Grint indicates that doses of methotrexate in the amount of 12.5 – 25 mg/week were given to the patients by oral, subcutaneous, or intramuscular administration.

In contending that Grint anticipated claim 1, the Petitioner relied on the combination of Grint’s statement that “methotrexate is generally present in from about 0.1 to about 40 mg/ml of carrier”[3] and the example of administration of methotrexate described in the study. The Petitioner further provided expert testimony alleging that one of ordinary skill in the art would understand Grint to disclose subcutaneous administration of methotrexate in concentrations greater than 30 mg/ml for treatment of autoimmune diseases.

In response, the Patent Owner argued that Grint’s disclosure of using methotrexate is so broad and generic that it fails to provide any information on how to administer the methotrexate. The Patent Owner supported his position by asserting that Grint never correlated any methotrexate concentration with any particular mode of administration. Consequently, one of ordinary skill in the art would not understand all of the points within Grint’s disclosed concentration range to be applicable to each disclosed mode of administration.

Siding with the Patent Owner, the Board held that the Petitioner failed to establish that claim 1 was anticipated by Grint. In reaching its decision, the Board noted that anticipation requires a prior art reference to not only disclose all the elements of the claim, but also to disclose those elements as “arranged as in the claim.”[4] To establish that Grint disclosed all the recited elements as arranged as in claim 1 of the ’231 patent, the Board held that the Petitioner must show that the upper portion (i.e., above 30 mg/ml) of Grint’s disclosed range of 0.1 mg/ml to 40 mg/ml is linked to subcutaneous administration. The Board found that one of ordinary skill in the art would not envision the upper portion of Grint’s disclosed concentration range to apply specifically to subcutaneous administration. The Board based this finding on the fact that the only embodiment in Grint that discloses subcutaneous administration is tied to a dose of 12.5-25 mg/week.

Moving forward, when seeking to anticipate a claimed range, petitioners should be cautious in relying on a reference disclosing a broader, overlapping range. As reflected in this decision, petitioners should be sure that the reference discloses the recited range with sufficient specificity.

Furthermore, petitioners should always consider challenging the patentability of the claimed range on the grounds of obviousness. Rather than proving that the reference discloses the claimed range with sufficient specificity, the petitioner may establish obviousness by showing that any differences between the disclosed and recited ranges may be discovered by routine experimentation. Establishing obviousness through routine experimentation gives the petitioner more flexibility in its approach, compared to the more rigid analysis conducted under an anticipation challenge.