Patent Invalidity Strategy

Patent invalidity arguments must be proven by clear and convincing evidence in district court (Microsoft v. i4i, S.Ct. 2011) — a higher standard than the preponderance standard used at PTAB — and selecting and prioritizing arguments requires strategic judgment: THE GROUNDS FOR INVALIDITY: § 101 INELIGIBLE SUBJECT MATTER: patent claims an abstract idea; law of nature; or natural phenomenon; Alice/Mayo two-step test; most powerful for software and business method patents; can be raised at any stage including motion to dismiss; § 102 ANTICIPATION: a single prior art reference must disclose EVERY element of the claim; each element must be explicitly or inherently present in the single reference; anticipation requires that someone 'described' the claimed invention before the critical date; no picking and choosing from multiple references; § 103 OBVIOUSNESS: the claimed invention would have been obvious to a person of ordinary skill in the art (POSITA) at the time of filing; can combine multiple references; KSR flexible standard requires: motivation or reason to combine; reasonable expectation of success; secondary considerations weigh against obviousness; § 112(a) LACK OF WRITTEN DESCRIPTION: specification did not demonstrate the inventor's possession of the full scope of the claimed invention at the time of filing; particularly important for genus claims; § 112(a) LACK OF ENABLEMENT: specification does not enable one of ordinary skill to make and use the full scope of the claims without undue experimentation; Amgen v. Sanofi (S.Ct. 2023) held that broad functional genus claims on antibodies were not enabled by limited examples; § 112(b) INDEFINITENESS: claims do not inform one of ordinary skill of the invention's scope with reasonable certainty (Nautilus v. Biosig, S.Ct. 2014); PRIORITIZATION STRATEGY: § 101 first (can win at pleadings; no claim construction needed; low cost); then IPR petition for § 102/103 (cheaper than district court; higher success rate at PTAB); § 112 in district court (expert-intensive; Amgen v. Sanofi has strengthened these arguments for functional genus claims); FILE FOR IPR EARLY: the 1-year § 315(b) bar runs from service of the complaint; missing this window forecloses IPR as an option.

An invalidity prior art search for litigation support differs significantly from a patentability search conducted before filing — the litigation search is broader, more exhaustive, and must cover non-obvious sources that an examiner might have missed: PRIOR ART CATEGORIES UNDER AIA (35 U.S.C. § 102): prior art is anything that was: (a) patented; described in a printed publication; in public use; on sale; or otherwise available to the public before the effective filing date; (b) describes the invention AND was made by the same inventors = not prior art; NO ABSOLUTE NOVELTY UNDER PRE-AIA: for patents filed before March 16, 2013 (pre-AIA patents are still litigated today): § 102(a): known or used in the US; patented or described in a printed publication anywhere BEFORE the invention date; § 102(b): patented or described in a printed publication; or in public use or on sale IN THE US more than 1 year before the application filing date; INVALIDITY SEARCH METHODOLOGY: START WITH WHAT THE EXAMINER SAW: examiner's search log (in the prosecution history); if the examiner missed an obvious search, you may find art they overlooked in the obvious places; PATENT LITERATURE: Google Patents; USPTO PAIR; Espacenet (European Patent Office; covers 150+ million documents); Derwent Innovation (most comprehensive; $$$); CIPO (Canadian); JPlatPat (Japanese); CNIPA (Chinese); KIPO (Korean); Patentscope (WIPO PCT); MOST IMPORTANT NON-PATENT LITERATURE (NPL) SOURCES: academic journals (PubMed for biotech/pharma; IEEE Xplore for electronics/CS; ACM Digital Library for software; Scopus; Web of Science); conference proceedings (SIGGRAPH for graphics; USENIX for systems; CHI for HCI); technical standards (IETF RFC; IEEE standards; 3GPP; ETSI — critical for SEP litigation); textbooks and technical books; patent applications (published 18 months after filing; may be prior art even if never granted); LESS OBVIOUS BUT VALUABLE SOURCES: product manuals and user guides (often ignored by examiners); open source code commit histories (GitHub; SourceForge; Gitorious); newsgroup archives (Usenet; Google Groups archive going back to 1980s); academic theses and dissertations (ProQuest Dissertations; institutional repositories); trade publications and industry magazines; TIMING CRITICAL UNDER PRE-AIA: must establish exact date of prior art (publication date; public disclosure date; on-sale date); affidavits from persons who saw; used; or sold the technology may be needed; AIA: if patent filed post-March 16, 2013, only 'publicly available' art before effective filing date counts.

Inter partes review (IPR) at the Patent Trial and Appeal Board (PTAB) is often a defendant's most powerful invalidity tool — offering a faster timeline, lower evidentiary standard, and better statistical success rates than district court invalidity defenses: IPR vs. DISTRICT COURT INVALIDITY — THE KEY DIFFERENCES: EVIDENTIARY STANDARD: PTAB: preponderance of the evidence (more likely than not); much lower bar than district court's clear and convincing evidence; IPR petitioners prevail in part or whole on ~60-70% of instituted trials; CLAIM CONSTRUCTION: PTAB uses Phillips standard (ordinary and customary meaning as understood by POSITA); same as district court; consistent construction is important for parallel proceedings; GROUNDS: IPR can only challenge claims on § 102 (anticipation) and § 103 (obviousness) grounds based on patents or printed publications; CANNOT challenge on § 101; § 112; prior use; prior sale; or experimental use grounds; PGR (post-grant review, within 9 months of grant) can use any invalidity ground; COST: IPR petition filing + attorney fees: $400,000–$600,000 through final written decision; significantly cheaper than district court trial; TIMELINE: IPR trial to final written decision: approximately 12–18 months from petition filing; district court trial: 2–4 years; STAY: district court often stays the district court case pending IPR — stops expensive discovery; trial preparation; expert fees during IPR period; THRESHOLD — WHEN PTAB WILL INSTITUTE: petitioner must show 'reasonable likelihood' it prevails on at least one challenged claim; institution rates have declined from ~80% (2012-2016) to ~60-65% (2022+); APPLE RULE (SAS Institute v. Iancu, S.Ct. 2018): PTAB must either institute on all grounds and claims in petition or deny institution; cannot partially institute; FINTIV RULE AND DISCRETIONARY DENIAL: PTAB uses Apple v. Fintiv 6-factor test to determine whether to discretionarily deny institution when parallel district court proceeding is advanced; controversial; subject to Director review; 35 U.S.C. § 315(b) 1-YEAR BAR: IPR petition must be filed within 1 year of service of the complaint alleging infringement; missing this deadline = forever barred from IPR on those patents; ESTOPPEL (35 U.S.C. § 315(e)(2)): after final written decision, petitioner is ESTOPPED in district court and ITC from asserting invalidity on any ground petitioner raised OR REASONABLY COULD HAVE RAISED in IPR; strategy: choose IPR grounds carefully; do not raise every possible § 102/103 argument in IPR — save some for district court backup.

Section 112 invalidity arguments — written description and enablement — have become increasingly powerful tools for challenging broad pharmaceutical and biotechnology patents, particularly after the Supreme Court's 2023 decision in Amgen v. Sanofi: WRITTEN DESCRIPTION (§ 112(a) FIRST PARAGRAPH): the specification must describe the claimed invention in sufficient detail to show that the inventor actually possessed the full scope of the invention at the time of filing; KEY CASES: Ariad Pharmaceuticals v. Eli Lilly (Fed. Cir. en banc 2010): confirmed written description as a separate requirement from enablement; rejected the argument that enablement alone satisfies § 112(a); Nutraceutix v. Chesapeake Research (Fed. Cir. 2014): claim to a genus must be supported by representative species in the specification; GENUS CLAIMS — THE HARDEST TO SUPPORT: a claim to a class of millions of compounds is hard to support with written description of a few examples; courts look for: representative number of species in the specification; common structural features; functional grouping with shared structure; ENABLEMENT (§ 112(a) FIRST PARAGRAPH): the specification must teach one of ordinary skill in the art how to make and use the claimed invention across the full scope of the claims WITHOUT undue experimentation; WANDS FACTORS (eight factors courts consider for undue experimentation): (1) quantity of experimentation needed; (2) amount of direction or guidance in specification; (3) presence/absence of working examples; (4) nature of the invention; (5) state of the prior art; (6) relative skill of those in the art; (7) predictability of the art; (8) breadth of the claims; AMGEN v. SANOFI (S.Ct. 2023) — LANDMARK ENABLEMENT RULING: BACKGROUND: Amgen's PCSK9 antibody patents (cholesterol-lowering treatment) claimed a functional genus — any antibody that (1) binds to PCSK9 and (2) blocks the protein from binding to LDL receptors; Amgen disclosed 26 specific antibodies with structural descriptions; THE COURT'S HOLDING (unanimous, 9-0): the functional genus claim was NOT enabled; reason: Amgen claimed every antibody achieving a particular function but provided only 26 examples out of potentially millions of possible antibodies achieving that function; enabling any particular antibody doesn't enable the full scope of claiming EVERY antibody achieving that function; Wands factor 1 (quantity of experimentation) was dispositive — scientists would need to screen millions of possible antibodies to find all those within the claim scope; IMPACT: dramatically strengthened invalidity arguments against broad functional genus claims in pharma and biotech; IMPLICATION FOR PATENT DRAFTERS: do not claim broad functional results ('any antibody that blocks X') without structural limitations; narrow claims to specific structural classes with representative examples; consider functional + structural hybrid claims; IMPACT FOR DEFENDANTS: Amgen framework applies beyond antibodies — use it against any broad functional claim covering a vast set of possible embodiments.