Introduction

On June 7, 2017, Kyle Bass received his last final written decision in a long list of PTAB decisions rendered over the past two years as Kyle Bass sought to invalidate pharma patents.  U.S. Patent No. 8,476,010 (the “’010 patent”) is owned by Fresenius Kabi USA, and is the only Orange Book patent covering Fresenius’ anesthetic drug Diprivan®.  The Board found all challenged claims unpatentable as obvious.

Background and Decision

Diprivan® is a commonly used intravenous anesthesia agent.  The key ingredient, propofol, is an insoluble oil that must be incorporated with solubilizing agents, solvents, or an oil in water emulsion.  If the mixture is not stored in inert containers, propofol degrades.  Claims of the ’010 patent cover sterile propofol-oil in water emulsion mixtures stored in an inert container.  The specification lists advantages of the invention including excellent exhibition of antimicrobial activity.

On November 25, 2015, Kyle Bass and Erich Spangenberg filed an inter partes review (“IPR”) of claims 1, 13-15, 17, 18, 20, and 24-28 of the ’010 patent—all on obviousness grounds—and on June 8, 2016 the Board instituted review.  The claims were challenged in view of two prior art combinations, each containing three prior art references.  (IPR2016-00254, Paper No. 47 at 5.)  The primary reference in each combination was a Diprivan® Physician’s Desk Reference that provided product information dating back to 1997.  (Id. at 5.)  The main secondary reference was also shared among the combinations, and was an article discussing the storage of Diprivan®.  Each combination also had a third reference, the first combination included a patent that discusses siliconizing containers and rubber stoppers, and the second combination included a patent application that discusses the same.  (Id. at 10, 28.)  The Board found all of the challenged claims to be obvious in light of the cited prior art and held them all unpatentable.  (Id. at 30.)  Fresenius presented no objective evidence of nonobviousness.

Summary of Bass’s IPR Activity

This final written decision marks the end of Bass’s challenges to pharma patents.  Over the past two years, Bass filed 37 IPR petitions, challenging 30 patents, covering 17 different drugs.  The Board instituted 21 of those petitions.  In two instances (Bravecto® and Suprenza®), opposing parties declined to file a response or abandoned the contest, resulting in cancelled claims.  As shown in the table below, Bass was successful in 10 of the 19 IPRs where the PTAB issued a final written decision.  That means Bass had a trial win rate of 53%.  While Bass committed to seeing the IPR challenges through final written decision, it appears as though Bass is not participating in appeals of PTAB decisions in which he successfully invalided patent claims.   Bass has not filed an IPR since March of 2016, so this is likely the last we will hear from Bass’s pharma patent challenges.

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