any challenged claim within one year. For good cause, the
PTAB may extend this one-year period by up to six months.
A final written decision will issue within 12 to 18 months of
the petition date, which is typically much shorter than district
court litigation, which averages about two and a half years, or
Notably, there is no requirement that a petitioner have
standing to petition the PTAB for inter partes review. Rather,
the only limits are that the petitioner cannot be the owner of
the patent, and cannot have been sued for infringement of
the patent more than one year before filing a petition. As a
result, IPR proceedings present an attractive option to parties
that cannot obtain personal jurisdiction over a patent holder
in district court or lack standing to challenge validity in
district courts. For example, foreign parties contemplating
entering US markets to compete with patented products can
petition the PTAB for inter partes review of a competitor’s
patent in advance of entering the US market.
There is a downside to IPR—the potentially broad scope
of statutory estoppel under 35 U.S.C. § 315(e). Section 315(e)
prevents a petitioner in an inter partes review from asserting
in a civil action or before the USPTO any ground of invalidity
which the petitioner “raised or reasonably could have raised”
during the inter partes review. However, recent court cases
interpreting 35 U.S.C. § 315(e) have shown a trend towards
a narrow interpretation. For example, the Federal Circuit
has held that Section § 315(e) does not estop IPR petitioners
from raising grounds of invalidity in district court or at
the USPTO which were raised in the IPR petition but not
instituted by the PTAB. (See Shaw Indus. Grp., Inc. v.
Automated Creel Sys., Inc., 817 F.3d 1293, 1300 (Fed. Cir.
2016)). District courts are starting to follow. (See Intellectual
Ventures I, LLC et al. v. Toshiba Corp. et al. (“IV”), Civ. No.
13-453-SLR (D. Del. Jan. 11, 2017)).
For the foreseeable future, IPRs will continue to be an
expeditious and powerful tool for challenging the validity
of US patents.
Post-Grant Review (PGR)
Post-grant reviews allow broad invalidity arguments, but
for a brief window of time. Thus far, PGRs have been the
least popular post-grant proceeding, with only about 1%
of the petitions filed seeking post-grant review. Petitioners
may seek post-grant review of any US patent which has
at least one claim having an effective filing date on or after
March 16, 2013, and has been granted or reissued within the
last nine months. Consequently, relatively few patents are
eligible for PGR at any given time. Petitions for post-grant
review may be based on any statutory provision for invalidity:
35 U.S.C. § 101 (ineligible subject matter), § 102 (lack of
novelty), § 103 (obviousness), and § 112 (lack of enablement
or written description).
The timeline for a PGR proceeding is similar to that of IPRs.
Once the PTAB has issued a final written decision granting
a petition to institute a PGR, the AIA requires that the PTAB
issue a final written decision on the patentability of any
challenged claim within one year.
Similar to IPRs, there is no requirement for standing by the
petitioner, or personal jurisdiction over the patent to petition
the PTAB for post-grant review. Rather, the only limits are
that the petitioner cannot be the owner of the patent, and
cannot have already sued in district court to invalidate
As with IPRs, prospective petitioners should consider the
potentially broad scope of statutory estoppel, which parallels
the IPR estoppel provision.