An Emerging PTAB Threat for Bio/Pharma: Leveraging Written Description Vulnerabilities in IPR

Bio/pharma patents are rarely targeted in inter partes review (IPR) proceedings because their technical vulnerabilities often relate to written description and/or enablement. IPR, of course, is restricted in scope to grounds of unpatentability that are based on patents and printed publications. Claims in the unpredictable arts, even when challenged in IPR, can be relatively tougher to invalidate as compared to patents in the predictable arts. Section 112 (written description) issues can be litigated in an IPR—but Section 112 cannot provide the stand-alone trial ground.

For example, where a subject patent claims priority to one or more prior filings, the Section 112 support of those filings is properly litigated in IPR if the claims of the subject patent are argued as lacking support in the earlier filings. The distinction is that Section 112 is not being assessed as a stand-alone challenge, but rather, as part of the priority assessment to determine the applicability of intervening prior art under Sections 102 and 103.

Key Takeaways for Practitioners

The above IPR strategy is not new. However, it might be significantly more valuable to bio/pharma patent challengers as a mechanism to force an Amgen analysis on older patent portfolios via IPR. Amgen Inc. v. Sanofi, 143 S. Ct. 1243 (2023). This is because while PGR is available for stand-alone Section 112 challenges (at least for post-2012 patent filings), the limited PGR window (nine months from issuance) has typically long since closed by the time most high-value bio/pharma patents are litigated. Likewise given its expansive scope, even when available, PGR brings added estoppel liability for patent challengers. For these reasons, IPR provides the optimum path to Section 112 review.

To seek IPR for purposes of litigating Section 112, it is not enough to just point out that the claims are not supported. Intervening art must be identified, and there are a few intervening art scenarios that patent challengers might leverage to secure an Amgen analysis at the PTAB:

  1. Apply intervening art in an IPR that potentially invalidates the claims under Sections 102/103;
  2. Apply intervening art of the inventors in an IPR that shows further development of the claimed subject matter post-filing to prove them initially unsupported and to invalidate the claims under Sections 102/103; or
  3. Apply the earliest priority document as intervening art that demonstrates obviousness with its “research assignment” and simultaneously demonstrates that the inventor was not in possession of the invention for Section 112 purposes.

We expect to see a renewed interest in intervening art challenges at the PTAB as a mechanism for bio/pharma patent challengers to secure an Amgen analysis for undermining a portfolio of related patents.

To learn more from Wolf Greenfield’s Scott McKeown, please visit his most recent blog post.