12.3 Inter Partes Review (IPR) & Post-Grant Review (PGR)

Inter Partes Review (IPR) & Post-Grant Review (PGR)

The Leahy-Smith America Invents Act (AIA) created contested administrative trial proceedings before the Patent Trial and Appeal Board (PTAB) to provide fast, cost-effective alternatives to district court patent litigation. The two primary AIA post-grant trial proceedings are Post-Grant Review (PGR) (35 U.S.C. §§ 321–329) and Inter Partes Review (IPR) (35 U.S.C. §§ 311–319).

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Post-Grant Review (PGR) (35 U.S.C. §§ 321–329)

Post-Grant Review allows third parties to challenge the validity of a patent across virtually all statutory grounds shortly after the patent is issued.

Eligibility & Filing Window

• Patent Eligibility: PGR applies ONLY to patents subject to the First-Inventor-to-File (FITF) provisions of the AIA (effective filing date on or after March 16, 2013).
• Filing Window: A petition for PGR must be filed within 9 months of the patent grant date (or reissue grant date).
• Standing: Any person who is not the owner of the patent may file a petition for PGR, provided they have not previously filed a civil action challenging the validity of a claim of the patent.

Comprehensive Invalidity Grounds

Unlike IPR, PGR offers an extremely broad spectrum of invalidity grounds:

• 35 U.S.C. § 101: Patent eligible subject matter and utility;
• 35 U.S.C. § 102: Novelty / Anticipation (including prior public use, commercial sales, and oral disclosures);
• 35 U.S.C. § 103: Non-obviousness;
• 35 U.S.C. § 112: Written description, enablement, and definiteness (excluding best mode).

Institution Standard (§ 324(a))

The PTAB will institute a PGR trial if the petition demonstrates that it is "more likely than not" that at least one of the challenged claims is unpatentable, or if the petition raises a novel or important legal question.

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Inter Partes Review (IPR) (35 U.S.C. §§ 311–319)

Inter Partes Review is the most frequently utilized AIA trial proceeding. It provides a targeted mechanism to challenge patent claims based exclusively on printed prior art.

Eligibility & Timing

• Patent Eligibility: IPR applies to ALL patents, regardless of whether they were issued under pre-AIA first-to-invent rules or AIA first-inventor-to-file rules.
• Filing Window: A petition for IPR must be filed after the expiration of the 9-month PGR window (or after the termination of a PGR proceeding, if one was instituted).
• The One-Year Litigation Bar (§ 315(b)): An IPR petition is statutorily barred if filed more than 1 year after the date on which the petitioner, real party in interest, or privy was served with a complaint alleging infringement of the patent.

Narrow Prior Art Grounds (§ 311(b))

IPR challenges are strictly limited to invalidity grounds under 35 U.S.C. § 102 (anticipation) and § 103 (obviousness) based ONLY on prior art consisting of patents or printed publications. Inventions disclosed via prior public use, commercial sales, or § 112 indefiniteness/enablement defects cannot be asserted in an IPR petition.

Institution Standard (§ 314(a))

The PTAB will institute an IPR trial if the petition demonstrates that there is a "reasonable likelihood" that the petitioner would prevail with respect to at least one of the claims challenged in the petition.

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PTAB Trial Timeline & Standard of Proof

AIA post-grant trials follow strict statutory deadlines and procedural stages:

+-----------------------------------------------------------------------------------+
|                         PTAB AIA TRIAL STATUTORY TIMELINE                         |
+-----------------------------------------------------------------------------------+
| Month 0:   Petitioner files Petition (IPR or PGR).                                |
| Month 3:   Patent Owner Preliminary Response (POPR) filed (optional).            |
| Month 6:   PTAB Decision on Institution issued (within 3 months of POPR).       |
| Month 6-18: Discovery, Patent Owner Response, Petitioner Reply, & Oral Hearing.   |
| Month 18:  PTAB issues FINAL WRITTEN DECISION (Statutory 12-Month Trial Limit).    |
+-----------------------------------------------------------------------------------+

• 12-Month Trial Limit (§ 316(a)(11)): The PTAB is statutorily mandated to issue a Final Written Decision within 12 months of trial institution (extendable by up to 6 months for good cause).
• Preponderance of Evidence Standard: In PTAB proceedings, claims are evaluated under the preponderance of the evidence standard (over 50% likelihood), whereas district courts require clear and convincing evidence to invalidate an issued patent.

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Statutory Estoppel (35 U.S.C. §§ 315(e) & 325(e))

To prevent repetitive harassment of patent owners across multiple forums, the AIA enforces powerful statutory estoppel rules once the PTAB issues a Final Written Decision:

1. District Court & ITC Estoppel: The petitioner in an IPR/PGR proceeding (and any real party in interest or privy) is prohibited from asserting in district court or the ITC that a claim is invalid on any ground that the petitioner raised or reasonably could have raised during the post-grant proceeding.
2. USPTO Estoppel: The petitioner is barred from requesting or maintaining any USPTO proceeding (reexamination, IPR, or PGR) with respect to such claim on any ground raised or reasonably could have been raised.

"Reasonably Could Have Raised" Scope: Estoppel extends to any printed publication or patent prior art that a diligent searcher would have discovered and submitted in the petition.

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Tri-Party Comparison: IPR vs. PGR vs. Ex Parte Reexamination