PTAB

IPR2018-01566

Becton, Dickinson and Co. v. bioMerieux S.A.

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1. Case Identification

2. Patent Overview

  • Title: Method for Detecting Methicillin-Resistant Staphylococcus aureus (MRSA)
  • Brief Description: The ’337 patent relates to methods for detecting MRSA using multiplex DNA amplification. The claimed methods simultaneously test a sample for two distinct DNA segments: (1) the junction formed by the insertion of an SCCmec cassette into the S. aureus chromosomal DNA, and (2) a region of the mecA gene, which confers methicillin resistance. The presence of both segments is used to confirm an MRSA-positive result.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claim 15 under 35 U.S.C. §102

  • Prior Art Relied Upon: Oberdorfer (a 2006 European journal article), as evidenced by Huletsky (a 2004 journal article) and Warren (a 2004 journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the Oberdorfer reference, which was not considered during prosecution, discloses every limitation of claim 15. Oberdorfer described a study evaluating a commercial real-time PCR assay for MRSA (the IDI-MRSA assay). Petitioner provided evidence from Huletsky and Warren to establish that this IDI-MRSA assay was a known test that amplified only the SCCmec junction. Oberdorfer reported that this assay suffered from false positives caused by certain methicillin-sensitive S. aureus (MSSA) strains that contained the junction but lacked the mecA gene. Crucially, Oberdorfer then expressly disclosed a solution: "If the detection of the mecA gene were added into the IDI-MRSA test in the form of a multiplex approach, one could avoid the false-positive results caused by MSSA."
    • Key Aspects: Petitioner contended this statement explicitly teaches a method comprising a multiplex reaction amplifying both the SCCmec junction and a region of mecA, and detecting both to confirm MRSA, thereby anticipating claim 15. The argument hinged on the assertion that even though phrased as a suggestion, Oberdorfer's disclosure was enabling and placed the complete invention in the public's possession, as the underlying techniques were well-known.

Ground 2: Obviousness of Claims 15, 29-31 under 35 U.S.C. §103

  • Prior Art Relied Upon: Huletsky (a 2004 journal article on a real-time PCR assay), Oberdorfer (the 2006 journal article suggesting an improvement), and Sinsimer (a 2005 journal article on a multiplex beacon platform).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Huletsky disclosed a base real-time multiplex PCR method for detecting MRSA by amplifying the SCCmec junction. Huletsky itself acknowledged that its method could misidentify some MSSA strains as MRSA, creating false positives. Oberdorfer, in testing Huletsky's method, identified the same problem and explicitly suggested the solution: adding detection of the mecA gene via a multiplex approach to improve accuracy. Sinsimer provided the final piece, demonstrating that designing and using primers and molecular beacon probes to detect the mecA gene as part of a multi-target, single-tube PCR reaction was a successful and well-established technique. Together, Petitioner argued these references teach all limitations of independent claim 15. Dependent claims 29-31 add further details on the oligonucleotide sets (primers) and probes used for detection, which Petitioner asserted were also rendered obvious by the combination, as Sinsimer taught the specific design of such components for mecA detection in a multiplex system.
    • Motivation to Combine: A POSITA would be motivated to combine the references for a clear and compelling reason expressly stated in the prior art: to solve the known false-positive problem of the Huletsky assay. Oberdorfer provided the explicit rationale to modify Huletsky's assay to "avoid the false-positive results caused by MSSA." This would improve the diagnostic reliability of a commercially relevant test, a strong motivation for a skilled artisan.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in making the combination. Huletsky provided a functioning base multiplex assay. Oberdorfer provided the blueprint for the modification. Sinsimer demonstrated that the specific technical step required—adding primers and a distinctly-labeled molecular beacon probe for the mecA gene into a multiplex reaction—was not only feasible but had been successfully implemented in a four-color multiplex assay. Modifying Huletsky's two-fluorophore assay to a three-fluorophore assay by adding the mecA components taught by Sinsimer was therefore a predictable and straightforward implementation of known techniques to achieve a predictable result.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §325(d) would be inappropriate because the petition raises a ground based on a key prior art reference, Oberdorfer, that was never presented to or considered by the USPTO during the original prosecution. Petitioner asserted that the Examiner's "Reasons for Allowance" for the '337 patent were predicated on the finding that no cited references disclosed amplifying and detecting both the SCCmec junction and the mecA gene. Since Oberdorfer expressly suggests this very combination, Petitioner contended it presents significant new evidence warranting institution of review.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 15 and 29-31 of Patent 8,367,337 as unpatentable under 35 U.S.C. §102 and §103.