At the urging of Sandoz Inc. (“Sandoz”), the PTAB instituted review of claims 1, 2, and 5-7 of U.S. Patent No. 9,067,992 (“the ʼ992 patent”) on April 3, 2018.  The ʼ992 patent is entitled “Use of TNFα Inhibitor for Treatment of Psoriatic Arthritis,” and is assigned to AbbVie Biotechnology Ltd. (“AbbVie”).  The claims of the ʼ992 patent are generally directed to treating psoriatic arthritis comprising subcutaneous administration of 40 mg of adalimumab every other week. The claims also recite various outcomes associated with the treatment.  In its Petition, Sandoz presented four separate Grounds for unpatentability, and the PTAB instituted review on all four grounds.

Before reaching the Grounds presented by Sandoz, the PTAB first addressed the parties’ respective claim construction positions.  First, Sandoz argued that the preambles to independent claims 1 and 2 are statements of intended use, and therefore are non-limiting.  AbbVie countered that the preambles are limiting because they provide antecedent basis for the claims and are the only parts of the claims that recite psoriatic arthritis and refer to the “said patient,” which is further limited by a dependent claim.  However, the PTAB declined to reach a decision on whether the preambles are limiting, instead concluding that such a determination was unnecessary at this stage.

Although not presented as a claim construction dispute in Sandoz’s petition, Sandoz also asserted that the outcome limitations recited in the various claims are simply statements of intended results that do not convey patentability. Unsurprisingly, AbbVie disagreed.  AbbVie pointed out that the outcome limitations in the claims expressly require particular ACR scores to be achieved following treatment for at least 24 weeks.  Thus, according to AbbVie, the claims require a particular treatment term and a heighted efficacy requirement.  The PTAB agreed with AbbVie and concluded each of the outcome limitations is entitled to patentable weight.

Turning to Ground 1, Sandoz alleged that claims 1, 5, and 6 are anticipated by a publication (Mease 2004) disclosing the results of a clinical trial that evaluated the safety and efficacy of administering 40 mg of adalimumab subcutaneously every other week.  According to Sandoz, the publication describes the same clinical study that was added as an example to the ʼ992 patent specification in a continuation-in-part application.  As a result, the limitations of claim 1, which are based on the patient population and results of the clinical study, are expressly disclosed.  Sandoz further asserted that claims 5 and 6 are anticipated because they recite the clinical outcomes of that study. AbbVie did not contest the Mease 2004 disclosure in its preliminary response.  Instead, AbbVie asserted Ground 1 should be denied because it is irreconcilable with Sandoz’s position regarding the effect of the ACR outcome language. More specifically, AbbVie argued that Sandoz’s position that the outcome language is non-limiting means that Sandoz cannot then rely on those limitations to establish a later effective filing date that makes the Mease 2004 publication available as prior art.  The PTAB sided with Sandoz on this dispute and concluded that Sandoz’s arguments are permissible alternative arguments based on different asserted priority dates.  Moreover, the PTAB also concluded that the limitations are entitled to patentable weight.

Grounds 2-3 alleged the claims are unpatentable as obvious over various combinations of references. Grounds 2 and 3 are substantively similar, and, in fact, have two references in common. In its Preliminary Response, AbbVie did not contest that the references relied on in the Grounds collectively teach the claim limitations.  Instead, AbbVie argued there was no reasonable expectation of success in (1) using adalimumab to treat psoriatic arthritis, or (2) using 40 mg of adalimumab every other week to treat that condition.

In its Petition, Sandoz asserted that psoriatic arthritis and rheumatoid arthritis are closely related diseases that are both mediated by TNF-α.  Sandoz further asserted that both diseases can be treated with the same drugs using the same or similar dosing regimen.  Accordingly, Sandoz argued that prior art disclosing the use of a 40 mg every other week adalimumab dosing regimen for the treatment of rheumatoid arthritis would have rendered use of the same regimen and drug to treat psoriatic arthritis obvious.  AbbVie countered by arguing none of the cited prior art references disclose the use of adalimumab to treat psoriatic arthritis, and, in fact, none of the cited references even discuss a possible connection between adalimumab and psoriatic arthritis. AbbVie similarly argued that disclosures in the cited references regarding the use of other TNF-α inhibitors to treat psoriatic arthritis ignore both the complexities of the disease and the differences between other inhibitors and adalimumab.  According to AbbVie, without this discussion there cannot be a reasonable expectation of success.

The PTAB disagreed by explaining the record indicates that (1) TNF-α was implicated in rheumatoid arthritis and psoriatic arthritis, (2) other TNF-α inhibitors were successfully used to treat both diseases, and (3) based on the success of the other inhibitors, a person of ordinary skill  would have reasonably expected adalimumab to also be successful. Accordingly, the PTAB found a person of ordinary skill would have a reasonable expectation of success in using adalimumab to treat psoriatic arthritis.

Regarding the claimed dosing regimen, Sandoz asserted that a person of ordinary skill would have had a reason to use 40 mg every other week because the prior art discloses that other TNF-α inhibitors were used to treat both rheumatoid and psoriatic arthritis with the same dose and dosing regimen. Consequently, according to Sandoz, a person of ordinary skill would have reasonably expected success in using adalimumab at 40 mg every other week to treat psoriatic arthritis because the prior art taught using adalimumab at the same dose and dosing regimen to treat rheumatoid arthritis. AbbVie argued that Sandoz’s citation to various references describing dosing regimens for other TNF-α inhibitors confirm the uncertainty of dosing.  However, the PTAB found AbbVie’s arguments assumed that the FDA approved dose is the information that would have been relevant to a person of ordinary skill, but that this assumption was counter to the relevant obviousness inquiry.  Accordingly, the PTAB agreed with Sandoz that a person of ordinary skill would have had a reasonable expectation of success in using the claimed dosing regimen based on the current record.

Ground 4 utilizes the same references as Ground 3, but adds a fourth for purposes of claim 7, which depends from claim 2 and adds the limitation that the symptoms reduced by treatment are “progression of structural damage assessed by radiograph.”  Sandoz argued that this limitation is the inherent result of practicing the claimed method or, alternatively, the prior art taught that treating patients with TNF-α inhibitors led to the claimed result.  AbbVie asserted that Sandoz did not put on a sufficient case under either theory and, in particular, Sandoz’s inherency theory was entirely conclusory because it did not cite any data showing that a patient treated with the claimed method would necessarily achieve the claimed result.  However, the PTAB agreed with Sandoz that the claimed result was the inherent outcome of the claimed method based on the current record.  Consequently, the PTAB did not address Sandoz’s alternative theory that the prior art taught the claimed limitation.

We will continue to keep you updated on further developments.