Dr. Reddy’s Laboratories S.A. v. Indivior UK Limited

1. Case Identification

• Case #: IPR2019-00329
• Patent #: 9,687,454
• Filed: November 13, 2018
• Petitioner(s): Dr. Reddy’s Laboratories S.A. and Dr. Reddy's Laboratories, Inc.
• Patent Owner(s): Indivior UK Limited
• Challenged Claims: 1-5, 7-14

2. Patent Overview

• Title: Sublingual and Buccal Film Compositions
• Brief Description: The ’454 patent describes an oral, self-supporting, mucoadhesive film for sublingual or buccal administration. The film contains the active ingredients buprenorphine (an opioid agonist) and naloxone (an opioid antagonist) and is designed to be a film version of the prior art Suboxone® tablet, using an acidic buffer to control pH and achieve bioequivalence.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-5 and 7-14 by Myers

• Prior Art Relied Upon: Myers (Application # 2011/0033541)

• Core Argument for this Ground:

  • Loss of Priority Date: Petitioner’s primary argument is that the challenged claims are not entitled to their asserted priority date of August 7, 2009, from the parent ’571 application. The petition contends that key limitations, specifically the polymer weight percentage range ("about 40 wt % to about 60 wt %") and the buprenorphine-to-polymer weight ratio, were first introduced in a 2016 amendment and lack written description support in the ’571 application. Petitioner argues the ’571 application only disclosed broad, open-ended polymer amounts (e.g., "at least 25%") and provided no "blaze marks" to guide a Person of Ordinary Skill in the Art (POSA) to the specific, narrow ranges later claimed.
  • Myers as Anticipatory Prior Art: Because the claims are allegedly not entitled to the 2009 priority date, their effective filing date is the filing date of the application that issued as the ’454 patent, which is after March 16, 2013. Myers, which was published on February 10, 2011, therefore qualifies as prior art under post-AIA 35 U.S.C. §102(a)(1). Ironically, Myers is the published version of the same ’571 application that Petitioner argues fails to provide written description support. Petitioner asserts that under established case law, a disclosure can be sufficient to anticipate a later claim even if it is insufficient to provide written description support for that same claim.
  • Prior Art Mapping: Petitioner argues that Myers explicitly discloses every limitation of the challenged claims.
    • Independent claim 1 requires a mucoadhesive film with buprenorphine, naloxone, a water-soluble polymeric matrix, and an acidic buffer, all within specific weight ranges and ratios. Petitioner contends Myers discloses an oral, mucoadhesive film (limitation 1.preamble, 1.e); the exact claimed dosage ranges for buprenorphine and naloxone (1.b, 1.c); the 4:1 buprenorphine-to-naloxone ratio (1.f); and the inclusion of an acidic buffer (e.g., citric acid/sodium citrate) (1.d).
    • Crucially, Petitioner argues that while the parent application lacked written description for the polymer weight range (1.a), Myers discloses specific formulations in its Table 1 (e.g., 48.2% and 58.6% polymer by weight) that fall within the claimed "about 40 wt% to about 60 wt%" range, thereby anticipating it. Similarly, Myers is alleged to disclose the buffer-to-buprenorphine ratio (1.g) and the specific pharmacokinetic parameters (1.h).
    • The dependent claims (2-5, 7-14) are argued to be anticipated because they merely narrow the ranges or specify components (e.g., citric acid as the buffer, specific polymers) that are also expressly disclosed or exemplified in the Myers reference, particularly in its Table 1 formulations.

• Additional Grounds: In a footnote, Petitioner noted the concurrent filing of IPR2019-00328, which challenges claims 1-3 and 5-14 of the ’454 patent as obvious to a POSA as of August 7, 2009.

4. Key Claim Construction Positions

• Petitioner argued that for the purposes of this IPR, the term "acidic buffer" should be construed to mean "a weak acid [citric acid], its conjugate base [sodium citrate] or combinations of both that operate in the acidic pH range (i.e. less than pH 7.0)."
• This construction is asserted to be consistent with the patent's specification, which identifies citric acid and sodium citrate as buffer components, and aligns with the understanding of a POSA that a buffer functions to resist pH changes. This construction is central to mapping the "acidic buffer" limitation to the prior art.

5. Key Technical Contentions (Beyond Claim Construction)

• The petition's central technical argument is that the original ’571 application lacks adequate written description for the polymer weight and ratio limitations. Petitioner heavily relied on the "blaze marks" doctrine from Purdue Pharma, arguing that one cannot disclose a "forest" of possibilities (e.g., "any desired level" of polymer) and later claim a specific "tree" (e.g., "40 wt% to 60 wt%") without any guidance in the original disclosure pointing to that specific tree.
• Petitioner further contended that the experimental data in the original disclosure (specifically Table 5, which tested for bioequivalence) would direct a POSA away from concluding that the claimed polymer ranges were significant. It was argued that formulations with polymer amounts inside the now-claimed ranges failed bioequivalence tests, while the successful formulation's key difference was its buffer amount, not its polymer content. This allegedly shows the inventors did not possess the invention as claimed at the time of the original filing.

6. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be inappropriate because the evidence and arguments in the petition were not previously considered by the USPTO Examiner.
• The core of this argument is that the Examiner never issued an Office Action questioning the claims' entitlement to the 2009 priority date or analyzing the §112 written description support for the newly added limitations. Consequently, the Examiner never considered whether Myers would qualify as an anticipatory prior art reference, making the petition's primary ground entirely new.

7. Relief Requested

• Petitioner requested that the Board institute an inter partes review (IPR), proceed to trial, and find challenged claims 1-5 and 7-14 of Patent 9,687,454 unpatentable.