PTAB

IPR2021-00850

Spectrum Solutions LLC v. Longhorn Vaccines & Diagnostics LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Methods for Preserving and Stabilizing Nucleic Acids in Biological Samples
  • Brief Description: The ’467 patent discloses methods for preserving and stabilizing nucleic acids in a biological sample suspected of containing pathogens. The method uses a single-step aqueous composition comprising five reagent classes: chaotropes, detergents, reducing agents, chelators, and buffers, intended to denature proteins, inactivate nucleases, and kill pathogens without degrading the nucleic acid.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 2, 4, 7, 17-20, 22, 23, 29, 31, and 34-39 under 35 U.S.C. §102 over Birnboim

  • Prior Art Relied Upon: Birnboim (Application # 2004/0038269).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Birnboim discloses every limitation of the challenged claims. Birnboim teaches a one-step method using an aqueous composition to stabilize and preserve nucleic acids from biological samples (e.g., saliva) at room temperature for extended periods. Specifically, Petitioner pointed to Example 3 of Birnboim, which discloses a "nucleic acid-preserving solution" containing urea (a chaotrope), sodium dodecyl sulfate (a detergent), sodium ascorbate (a reducing agent), CDTA (a chelator), and TRIS-HCl (a buffer). Petitioner asserted this composition meets all the component requirements of independent claim 1. Further, the concentrations disclosed for these components in Birnboim’s examples and specification were argued to fall within the ranges recited in dependent claim 2, thereby anticipating it and other dependent claims specifying particular reagents (e.g., claim 4 for SDS, claim 7 for TRIS) and storage conditions.

Ground 2: Obviousness of Claims 10, 11, 24, 25, and 28 over Birnboim in view of Mori

  • Prior Art Relied Upon: Birnboim (Application # 2004/0038269) and Mori (WO 2005/111210).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claims requiring a surfactant or defoaming agent. Petitioner argued that Birnboim’s base composition discloses the five core reagents, and its method involves vigorous shaking, a step known to cause foaming, particularly in the presence of detergents like SDS. Mori teaches a "nucleic acid-solubilizing reagent" containing similar components (chaotrope, surfactant, etc.) and discloses that adding a defoaming agent, such as a silicone polymer, is preferable to reduce foaming during homogenization treatments like high-speed stirring.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would have been motivated to add a defoaming agent as taught by Mori to Birnboim’s composition. This addition would be a simple and predictable solution to the known problem of foaming caused by agitation of detergent-containing solutions, thereby improving the reliability of subsequent analysis, such as PCR, where bubbles can interfere with results.
    • Expectation of Success: A POSA would have had a reasonable expectation of success because Mori teaches using defoaming agents in highly similar nucleic acid solutions containing chaotropes and detergents. Mori also discloses concentration ranges for the defoaming agent (0.1% to 10%) that overlap with the range recited in claim 10 (0.0001% to 0.3%), making the combination predictable.

Ground 3: Obviousness of Claim 12 over Birnboim in view of Das

  • Prior Art Relied Upon: Birnboim (Application # 2004/0038269) and Das (Application # 2005/0123928).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addressed claim 12, which specifies that the pathogens are influenza virus or bacteria that cause tuberculosis. Petitioner contended that Birnboim teaches its composition can be used to preserve nucleic acids from generic bacteria and viruses. Das is specifically directed to detecting tuberculosis-causing mycobacteria and discloses a lysis buffer containing the same five classes of reagents as Birnboim: a chaotrope (guanidinium isothiocyanate), detergent (N lauryl sarcosyl), reducing agent (2-mercaptoethanol), chelator (EDTA), and buffer (Tris).
    • Motivation to Combine: Since both references teach virtually identical compositions for the same general purpose (lysing cells and preserving nucleic acids), a POSA would have been motivated to apply Birnboim’s well-disclosed preservation method to the specific pathogen context taught by Das. This would amount to nothing more than using a known composition for its intended purpose on a specific, known type of biological sample.
    • Expectation of Success: A POSA would have expected success because Das demonstrates that this type of five-reagent composition is effective for lysing tough mycobacterial cells and preparing their DNA for analysis. The underlying chemical principles are the same, making the successful application of Birnboim’s composition to tuberculosis samples predictable.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 1-9 and 15-39 are obvious over Birnboim alone. Other grounds combined Birnboim with Mori, Helftenbein (Patent 6,776,959), and Birnboim2006 (WO 2006/096973) to argue the obviousness of adding internal positive controls (claims 13, 14, 26, 40-42) and other claimed features.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-42 of the ’467 patent as unpatentable.