Boehringer Ingelheim filed the petition at issue in IPR2015-00417 concurrently with the petitions at issue in IPR2015-00415 and IPR2015-00418 to challenge patents protecting methodologies for treating rheumatoid arthritis (RA) with rituximab, an FDA-approved antibody for treating certain cancers.  The IPR2015-00417 petition specifically challenged the fourteen claims of U.S. Patent No. 7,976,838, which are drawn to methods of administering rituximab to RA patients not responding to TNF-α inhibitors, a subset of RA patients.  The PTAB instituted an IPR of two of the 19 obviousness grounds contained in the petition.  Given the number, and nature, of grounds to be reviewed, and the outcome, it is apparent that the more grounds found in a petition, the greater the chance that the best arguments will be lost in the shuffle.

The PTAB’s analysis began with a claim construction determining that the claim preambles, which recite treating a patient population of RA patients not responding to TNF-α inhibitors, recite the “essence of the invention,” and are limiting.  Given this claim construction, the two grounds based on anticipation over Edwards I or a Genentech Press Release fell because neither reference expressly disclosed such a patient population, and neither reference inherently disclosed that population, which constituted about 40%, not 100%, of all RA patients.  Viewed in another light, the references taught treatment of 100% of RA patient non-responders, while also teaching treatment of RA patient responders.  On this view, the cited references did inherently disclose treatment of RA non-responders, but Petitioner didn’t argue this position, and the PTAB didn’t adopt this view.

Of the 19 obviousness grounds in the petition, the PTAB granted review on two grounds, one for claims 1-5 and 7-14 and the other for claim 6.  The institution decision revealed that there was a reasonable likelihood that claims 1-5 and 7-14 were obvious under 35 U.S.C. § 103(a) over Edwards I and Tuscano.  Edwards I was characterized as disclosing the claimed method but for the choice of patient population, i.e., RA patients not responding to TNF-α inhibitors.  Tuscano, like DeVita, was found to disclose administration of rituximab to RA patients not responding to a TNF-α inhibitor, as assessed by lack of response to the anti-TNF-α antibody infliximab.  The PTAB determined that Tuscano cured the lone deficiency in Edwards I, establishing a reasonable likelihood that claims 1-5 and 6-14 were obvious over the combined references.

Dependent claim 6 added the limitation that the patient be further treated with a corticosteroid regimen comprising methylprednisolone and prednisone.  The PTAB determined that Petitioner established a reasonable likelihood of showing that this claim was obvious over Curd, DeVita and Edwards IV.  Curd was found to disclose treatment of RA patients with one or more doses of rituximab, in combination with administration of methotrexate and corticosteroids (e.g., methylprednisolone, prednisolone, dexamethasone).  DeVita was characterized as disclosing the administration of rituximab to RA patents non-responsive to TNF-α inhibitors.  Edwards IV disclosed multiple doses of rituximab administered to RA patients along with prednisolone.  None of the cited references disclosed the claim-recited dosing schedule, but Petitioner argued that it would have been routine for a practitioner in the art to adjust from dosages disclosed in the references, i.e., 4 doses totaling 1500 mg/m² or 2100 mg/m², to 2 doses totaling 2000 mg/m² rituximab, and the PTAB agreed.  The PTAB found a reason to modify the administration schedule of the combined references in improved patient compliance due to fewer administrations of rituximab.

In considering the Patent Owner’s rebuttal, the PTAB rejected arguments based on secondary considerations of non-obviousness because a nexus between the evidence and novel elements of the claims had not been established.  A few additional obviousness grounds were expressly considered and rejected by the PTAB for failing to disclose or suggest a RA patient not responding to TNF-α inhibitors.  Beyond addressing these few grounds, the PTAB reasoned that Petitioner had established a reasonable likelihood that all 14 claims of the ‘838 patent would be obvious, the PTAB exercised its discretion to decline to institute an IPR on any of the remaining 15 obviousness grounds.  This reasoning expands beyond redundancy on the merits as a basis for declining a ground on which to challenge a patent.  Once a single ground is determined to present a reasonable likelihood that a given claim is unpatentable, all other grounds for challenging that claim can be declined.

[W]e exercise our discretion and decline to institute on the other grounds in the Petition [because] there is a reasonable likelihood that the challenged claims 1-14 are unpatentable based on the grounds of unpatentability for which we already institute an inter partes review.

This institution decision, like the decision in IPR2015-00415, illustrates the risk in presenting overlapping or duplicative grounds for requesting review of a U.S. patent.  In this decision, the PTAB relied on Tuscano as disclosing the treatment of RA patients not responsive to TNF-α inhibitors for claims 1-5 and 7-14, but relied on DeVita for an analogous disclosure in considering the obviousness of claim 6.  It is possible that one or the other, but not both, of these references will be found wanting in the merits phase.  In that instance, Petitioner will be unable to substitute the effective reference because review based on that particular ground was denied in the institution decision, which is not appealable.