The Patent Trial and Appeal Board issued one decision in TC 1600, which denied institution of an IPR. The petition was filed by Argentum Pharmaceuticals LLC (“Argentum”) against Merck Patentgesellschaft (“Merck”). The decision is as follows:

Argentum Pharms. LLC v. Merck Patentgesellschaft, No. IPR2018-00423 (Decision Entered July 23, 2018):  In this Petition, Argentum challenged US Patent No. 8,673,921 (“the ’921 patent”) as anticipated by the Böttcher reference and obvious in view of the Böttcher, Bartoszyk, Pavia, and Byrn references. Merck filed a preliminary response to the Petition. The ’921 patent relates to polymorphic forms of vilazodone hydrochloride (VHCl), which is the active ingredient of antidepressant VIIBRYD®. The claims at issue recite a crystalline modification of VHCl or a specific crystalline form of VHCl anhydrate (Form IV).

The Board exercised its discretion to deny the Petition under 35 U.S.C. § 325(d) because the same or substantially the same prior art or arguments were previously presented to the Office. Among the four references cited by Argentum, Böttcher was identified in the prosecution as the closest prior art; Bartoszyk was referenced in the background section of the ’921 patent; and Pavia and Byrn are excerpt from textbook related to routine crystallization technique at the time of the invention and were not before the Examiner. Argentum asserted that the Examiner erred in evaluating Böttcher due to a failure to identify a specific example in Böttcher as the closest prior art, which discloses a mixture of crystallized VHCl, amorphous VHCl, and vilazodone free base. The Board disagreed and found that because the Examiner already identified Böttcher as the closet prior art, it is not necessary for the Examiner to narrow “the closest prior art” to the specific example in Böttcher. The Board found Bartoszyk cumulative or substantially cumulative to Böttcher because Argentum failed to identify any material differences between Bartoszyk and Böttcher. Thus, the fact that Bartoszyk was not cited in any office action rejection or discussed in the Notice of Allowability of the ’921 patent did not mean that Bartoszyk was not before and considered by the Examiner. The Board found Pavia and Byrn cumulative or substantially cumulative to Böttcher because Argentum failed to show that the Examiner would not have been aware of the textbook crystallization techniques disclosed by Pavia and Byrn. Finally, to support its obviousness arguments, Argentum presented experimental data showing that routine recrystallization of a present-day commercial VHCl could result in the claimed Form 4, and alleged that the use of the present-day commercial VHCl rather than the VHCl mixture disclosed in Böttcher would not likely result in different recrystallization outcomes. The Board agreed with Merck and found Argentum’s effort to create the claimed Form IV from the present-day commercial VHCl 16 years after the filing of the ’921 patent involved improper hindsight and did not warrant reconsideration of the art that was before and considered by the Examiner.