Post-grant oppositions for pharma patents (Part 3): A look at potential strategies

In FY2016, the percentage of patents that were found to be valid in the PTAB’s final written decision for the biopharma sector was quite high (~34% valid vs. 39% invalid), relative to other industries (AIA Trial Statistics,, accessed March 8, 2017). A well-planned strategy will help both a petitioner and patent owners (POs) maintain a strong position during a post-grant opposition (PGO) petition. In this third and final part of our three-part blog series, we offer insights on some potential strategies for petitioners and POs.

Offensive strategies for the petitioner

  • Filing a PGO petition during data exclusivity: Unlike Hatch-Waxman (HW) district court litigation (which is triggered by an ANDA submission along with a Paragraph IV challenge, and can only be filed after 4 years of data exclusivity), PGO proceedings can be filed against patents of interest during the data exclusivity period. The major drawback with this approach is that the petitioner will not receive the coveted 180-day market exclusivity that is given to the first ANDA filer who wins HW district court litigation; instead, the petitioner could open the market to all generics manufacturers after a successful PGO petition.
  • Filing a PGO petition after data exclusivity—first filers: The HW district court litigation period is potentially the most advantageous time for generics companies, especially first-filers, to utilize PGO proceedings [especially inter partes review (IPR), which must be filed within 1-year from the HW litigation start date]. The petitioner can use the early months of the district court litigation to develop a complete prior art landscape and then finalize the grounds and evidence to file the petition. If the patents are found to be invalid via IPR, it is more likely that the district court gives judgment in favor of the generics company, and that this judgment will be rendered more quickly. The first-filer in this case will also receive 180 days of market exclusivity.
  • Filing a PGO petition after data exclusivity—late filers: In another scenario, generics companies may decide to apply for an ANDA with a paragraph IV certification at a later stage, 2-4 years before patent expirations, around the time when the first filer’s HW litigations are reaching the trial phase. These late filers may use IPR as a parallel attack for the same patents at issue. If a late filer is able to invalidate the patent via IPR, it may also be able to obtain the required district (or higher) court final judgment in their favor, thus triggering the 75-day forfeiture timeclock on the 180-day exclusivity granted to first filers. By triggering the forfeiture or at least an early start of the 180-day exclusivity period, the late filer can enter the market sooner. IPR in parallel with HW court litigations may impose pressure on the PO, who may choose to settle and allow the generics companies to enter the market before patent expiration.

Some additional points to consider:

  • The petitioner should carefully consider the overlap between claims challenged in PGO proceedings and in district court. If the claims do not overlap, the court may not see fit to stay the HW litigation pending the outcome of the PGO.
  • Unlike in Post grant review (PGR), in an IPR proceeding, a third party may still use all other invalidity defenses (except printed publication and patents) in a further appeal to the Federal Circuit. Therefore, a petitioner should do a thorough prior art search to decide which grounds and PGO proceedings should be chosen to reduce the risk of estoppel after the final written decision.

Defensive strategies for the PO:

  • The PO can try to prevent claims from getting instituted by using the patent owner preliminary response (POPR). According to information released by the USPTO (AIA Trial Statistics,, accessed March 8, 2017), filling a POPR may increase the chances of institution denial by PTAB. Thus, the PO should do thorough research on the grounds and prior art evidence submitted in the petition and frame a strong response. They can leverage any evidence and expert testimony produced during the patent examination process. For example, in an IPR petition filed by Boehringer Ingelheim in 2015 challenging the validity of a patent claim protecting Rituxan (IPR2015-00418), the PO (Biogen) proved that the evidence submitted was not a printed publication but a clinical trial protocol in its POPR. PTAB ultimately denied the petition.
  • If the PO believes that the claims are strong and will not be invalidated, it is better to allow PTAB institution and follow the PGO process until the final written decision is delivered in the PO’s favor. It will limit the power of petitioner (through estoppel) from attacking the same patent claims in a later appeal.
  • The PO can also consider a settlement agreement, although it may not prevent PTAB from issuing the final written decision. In FY2016, 19% of the petitions were dismissed by PTAB, likely in most cases because both the parties agreed to settle (e.g., Accord Healthcare vs. Helsinn Healthcare and Roche [Palonosetron], PGR2014-00010, Sanofi-Aventis US LLC vs. Genentech [Cabilly], IPR2015-01624).

Ultimately, a carefully drafted patent application may best withstand a future PGO petition. As the claim construction standard in PGO proceedings is broadest reasonable interpretation (BRI), it is advisable for a PO to clearly define any potentially disputable claim terms or phrases while drafting a patent and avoid ambiguity in the claim language. The PO also may protect a brand by having a few pending patent applications; this may permit the PO to amend the scope of new claims in pending applications to protect that brand—keeping in mind that new claims should be patently distinct from any prior invalidated claims.