PTAB

IPR2017-01446

Taro v. APopharma Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: USE FOR DEFERIPRONE
  • Brief Description: The ’328 patent discloses methods for treating iron-induced cardiac disease in transfusion-dependent patients suffering from iron overload. The method comprises administering a therapeutically effective amount of the iron chelator deferiprone, allegedly based on the discovery that deferiprone preferentially reduces iron in the heart compared to other organs.

3. Grounds for Unpatentability

Ground 1: Anticipation by MIMS 1998 (Claims 1-11, 13-17, and 19)

  • Prior Art Relied Upon: MIMS 1998 (a December 1998 edition of the Monthly Index of Medical Specialties).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that MIMS 1998, a widely-known printed publication in India analogous to the Physician's Desk Reference, explicitly discloses every element of the challenged claims. It identifies deferiprone as an oral agent for treating "transfusion haemosiderosis," which Petitioner's expert defined as iron overload due to blood transfusions. MIMS 1998 also specifies an administration dose of 75 mg/kg per day. Petitioner contended this directly maps to the independent claims’ limitations of administering a therapeutically effective amount of deferiprone to a transfusion-dependent patient. For claims requiring an "iron-overload condition of the heart" (e.g., claims 1, 2, 6-9), Petitioner argued that the reference's broader disclosure of treating "iron-storage disease" inherently includes the spectrum of cardiac disease caused by systemic iron overload. Thus, Petitioner concluded that MIMS 1998 anticipates the claims, as any recited cardio-protective effects are an inherent result of the disclosed, known treatment method.

Ground 2: Anticipation by Olivieri Abstract 1995 (Claims 1-11, 13-17, and 19)

  • Prior Art Relied Upon: Olivieri Abstract 1995 (an abstract from the Program Book for the 37th Annual Meeting of The American Society of Hematology).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that the Olivieri Abstract 1995, a publicly distributed document from a major medical conference, teaches the treatment of "thalassemia major" patients with 75 mg/kg of deferiprone per day. As thalassemia major patients are by definition transfusion-dependent, this meets a key limitation. Critically, the abstract disclosed that prior to treatment, the patient cohort had an average T2 relaxation time ("TRT") of 23.9±6.4 msec, a value which Petitioner's expert explained is a clinical indicator of iron overload specifically in the heart. Petitioner argued this provides an explicit disclosure of treating patients already having an "iron-overload condition of the heart," directly anticipating claims 1, 2, and 6-9. The abstract's disclosure of oral administration and a 75 mg/kg dose was argued to anticipate the dependent claims as well.

Ground 3: Obviousness over Primary References (Claims 1-17 and 19)

  • Prior Art Relied Upon: Each of the primary references (MIMS 1998, Hoffbrand 1998, Olivieri Abstract 1995, Agarwal 2000, and Olivieri 1995) individually, when viewed with the general knowledge of a person of ordinary skill in the art (POSA).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that, to the extent any claim is found not to be anticipated, it is rendered obvious by each of the same primary references. The petition asserted that there are no discernible differences between the claimed methods and the methods disclosed in the prior art. Each reference individually teaches the oral administration of deferiprone at or around 75 mg/kg per day to treat transfusion-dependent patients with iron overload. This established the prima facie case for obviousness under 35 U.S.C. §103.
    • Motivation to Combine (for §103 grounds): The motivation was not to combine references, but to apply the known drug (deferiprone) to treat the known and severe consequences of iron overload, including cardiac disease. Petitioner argued that a POSA would have been strongly motivated to use deferiprone for this purpose because it was one of only two available iron chelators, and cardiac failure was the well-known leading cause of death in this patient population. The prior art's consistent reports on deferiprone's efficacy in reducing the body's total iron burden provided a clear reason to use it to address the most lethal manifestation of that burden.
    • Expectation of Success: A POSA would have had a reasonable expectation of success. Prior art studies, such as Olivieri 1995, reported on patients with established cardiac disease being treated with deferiprone. These studies measured iron levels in the heart (or proxies thereof), demonstrating that a POSA understood the correlation between reducing cardiac iron and treating the associated disease. Given deferiprone's proven ability to chelate iron, success in treating the cardiac effects of iron overload was a reasonable expectation, not a guarantee.

4. Key Claim Construction Positions

  • Petitioner’s entire invalidity case was predicated on the argument that the "intended result" clauses within the claims should be construed as non-limiting. Clauses such as "sufficient to treat iron induced cardiac disease" (claim 1), "sufficient to...reduce the iron burden in the heart" (claim 5), and "wherein said administration preferentially reduces the iron in the heart" (claims 6-10) were asserted to lack patentable weight.
  • The core of this position was that these phrases merely state the purpose or describe an inherent property of an old and known process—administering deferiprone to an iron-overloaded patient. Petitioner, citing Bristol-Myers Squibb Co. v. Ben Venue Labs., argued that newly discovered results of known processes directed to the same purpose are not patentable because such results are inherent. Since these clauses do not add a new or different manipulative step to the method, they should not be treated as limitations. This construction was positioned as dispositive, as it would mean the claims are directed only to a well-known method of administration, which is exhaustively described in multiple prior art references.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-17 and 19 of the ’328 patent as unpatentable under 35 U.S.C. §§ 102 and 103.