EPO Art. 56 • Biotech-Loop
CRISPR-Cas9 Prosecution Loop
EP 2 305 838 B1 • Art. 56 EPC Inventive Step
Basierend auf realer EPO BoA CRISPR-Cas9 Art. 56 Zurückweisung →
63/100 — Novelty Gap
Art. 56 EPC Einwand: eukaryotische Anwendung ist naheliegend aus Jinek 2012
| Patent |
EP 2 305 838 B1 — CRISPR-Cas9 System für Genom-Editierung in Eukaryontischen Zellen |
| Tech Field |
Biotechnology — CRISPR-Cas9 Gene Editing |
| OA Type |
EPO Examination Communication — Art. 56 EPC Inventive Step objection |
| Rejection |
Claim 1 lacks inventive step; Examining Division says extension from prokaryotic (Jinek 2012) to eukaryotic cells is obvious; no technical effect demonstrated for eukaryotic specificity. |
| Key Issue |
Eukaryotic cell scope vs. Jinek 2012 prokaryotic teaching; RNP vs. plasmid delivery distinction; off-target profile as technical effect. |
Agent: OA empfangen → Art. 56 EPC Einwand identifiziert → Gap-Analyse (eukaryotische Spezifität vs. Jinek 2012 prokaryotische Lehre) gestartet.
| Typ |
Nr. |
Inhalt |
| Unabhängig |
1 |
Use of a CRISPR-Cas9 system comprising a guide RNA (gRNA) and a Cas9 endonuclease for editing a target DNA sequence in a eukaryotic cell, wherein the gRNA directs the Cas9 endonuclease to the target DNA sequence via Watson-Crick base pairing. |
| Unabhängig |
2 |
A method for editing a target DNA sequence in a eukaryotic cell, comprising: providing a gRNA comprising a spacer sequence of 15–25 nucleotides; providing a Cas9 endonuclease; forming a ribonucleoprotein (RNP) complex; introducing the RNP complex into the eukaryotic cell; cleaving the target DNA sequence. |
| Unabhängig |
3 |
A kit comprising: a gRNA and a Cas9 endonuclease for use in a method according to claim 2. |
Rejection Summary
Art. 56 EPC — claim 1 lacks inventive step over D1 (Jinek 2012)
Primary Ref D1
- D1 Quelle: Jinek et al. (2012), "A programmable dual-RNA–guided DNA endonuclease in adaptive bacterial immunity", Science 337(6096):816-21
- Passage: D1 discloses single-guide RNA (sgRNA) + Cas9 for DNA cleavage in prokaryotic systems; teaches the basic CRISPR-Cas9 mechanism and the RNP complex formation principle.
- Note: D1 does not disclose use in eukaryotic cells, nuclear localization, or codon optimization.
Secondary Ref D2
- D2 Quelle: Cong et al. (2013), "Multiplex genome engineering using CRISPR/Cas systems", Science 339(6121):819-23
- Passage: D2 shows CRISPR-Cas9 works in human cells — but does not address RNP delivery vs. plasmid, or eukaryotic-specific off-target profile.
Examiner's Argument: Jinek 2012 establishes the CRISPR-Cas9 mechanism; D2 shows eukaryotic applicability; the skilled person would straightforwardly apply the system to eukaryotic cells. No unexpected technical effect.
PSA Technical Problem: How to provide a CRISPR-Cas9 system with improved precision and reduced off-target effects in eukaryotic cells?
Novelty Gap Score
63
/ 100
Agent: OA analysiert → Jinek 2012 prokaryotische Lehre vs. eukaryotische Ansprüche → Amendment-Vorschlag mit RNP-Delivery und quantitativen Schwellenwerten generiert.
Use of a CRISPR-Cas9 system comprising a guide RNA (gRNA) and a Cas9 endonuclease for editing a target DNA sequence in a eukaryotic cell,
characterized in that:
(a) the gRNA comprises a spacer sequence of at least 20 nucleotides that is complementary to the target DNA sequence,
(b) the Cas9 endonuclease is delivered as a ribonucleoprotein (RNP) complex with the gRNA, and
(c) the RNP complex is introduced into the eukaryotic cell by electroporation or lipid nanoparticle (LNP) delivery,
wherein the method achieves at least 90% on-target editing efficiency and less than 1% off-target cleavage at the top-5 predicted off-target sites, as measured by targeted amplicon sequencing.
Spec-Anker:
[0042] (RNP delivery via electroporation)
[0058] (LNP formulation)
[0071] (on-target efficiency >= 90%)
[0083] (off-target < 1%)
Key Additions vs. Original
| Element |
Zusammenfassung |
| 01 |
RNP delivery (not plasmid) — structural and functional distinction from Jinek 2012 |
| 02 |
Electroporation or LNP delivery — specific delivery modality required for in vivo application |
| 03 |
Quantitative efficiency thresholds: >= 90% on-target, < 1% off-target — measurable technical effect |
Agent: Anspruch 1 geändert → 3 strukturelle Unterscheidungsmerkmale (RNP-Delivery, Elektroporation/LNP, quantitative Schwellenwerte) → Counter-Arguments werden generiert.
RESPONSE TO EXAMINER'S COMMUNICATION
European Patent Application No. [App#]
Inventive Step Objection — Art. 56 EPC
The Examining Division objects that claim 1 lacks inventive step under Art. 56 EPC. Applicant submits the following response.
I. CLOSEST PRIOR ART AND TECHNICAL PROBLEM
D1 (Jinek 2012) represents the closest prior art and discloses sgRNA + Cas9 for DNA cleavage
in prokaryotic systems. The technical problem underlying the claimed invention is to provide
a CRISPR-Cas9 system suitable for precise genome editing in eukaryotic cells with improved
safety and delivery efficiency.
II. DISTINGUISHING FEATURES AND TECHNICAL EFFECT
The claimed subject-matter is distinguished from D1 by the following features:
(a) RNP delivery as ribonucleoprotein complex — D1 does not disclose RNP delivery; it teaches
plasmid-based or in vitro delivery. RNP delivery provides immediate Cas9 activity with
reduced persistence, which reduces off-target accumulation in dividing cells.
(b) Specific delivery modality: electroporation or LNP — these delivery methods are not disclosed
in D1 and are required for effective nuclear delivery in eukaryotic cells. The delivery modality
itself influences the intracellular Cas9 concentration profile and off-target kinetics.
(c) Quantitative efficiency thresholds (>= 90% on-target, < 1% off-target) — D1 provides no
quantitative disclosure of editing efficiency or off-target rates. The claimed thresholds
define a measurable technical effect not taught by D1.
III. NO MOTIVATION TO COMBINE D1 + D2
D1 addresses prokaryotic CRISPR-Cas9 function. D2 shows eukaryotic applicability but does not
teach RNP delivery or address the off-target profile. The combination of D1 + D2 would not
motivate the skilled person to specify RNP delivery as a structural element or to require
quantitative efficiency thresholds. The skilled person would not arrive at the claimed solution
without hindsight knowledge of the claimed invention.
IV. EUKARYOTIC SPECIFICITY AS TECHNICAL EFFECT
The restriction to eukaryotic cells is not merely a field-of-use limitation. Eukaryotic gene
editing requires:
- Nuclear localization signals (absent from D1 prokaryotic teaching)
- Codon optimization for mammalian expression (not disclosed in D1)
- Chromatin accessibility considerations (D1 addresses naked DNA only)
- Subcellular compartmentalization (nucleus vs. cytoplasm)
These constraints constitute technical differences that go beyond a "design choice" and
represent a genuine technical effect: reliable, reproducible gene editing in a complex
cellular environment.
V. CONCLUSION
The subject-matter of claim 1 involves an inventive step under Art. 56 EPC.
Allowance is requested.
Agent: Counter-Arguments generiert (8 Min.) → Autonomous Re-Search auf amended Claims gestartet.
| Rank |
Patent / Dokument |
Score |
Unterscheidung |
| 1 |
WO 2014/191499
Mali et al., 2013 |
52/100 |
CRISPR in human cells — no RNP delivery, no quantitative efficiency thresholds |
| 2 |
US10,000,772 B2
Intellia Therapeutics |
31/100 |
RNP delivery disclosed later — not in D1/D2 timeframe; no LNP as claim element |
| 3 |
EP 2 871 522 B1
Toolgen, 2016 |
28/100 |
Korean CRISPR — eukaryotic, but no RNP/LNP specification |
| 4 |
Zhen et al. 2015
NPL — RNP electroporation |
44/100 |
RNP electroporation in human cells — partial overlap, no LNP |
| 5 |
Doudna & Charpentier 2014
NPL — CRISPR-Cas9 |
38/100 |
Foundational but prokaryotic; no quantitative off-target data |
Re-Search Verdict
No prior art combines RNP delivery + LNP + quantitative efficiency thresholds in eukaryotic cells. Score delta: highest hit falls from 87 → 52. Confidence: 81%.
Confidence: 81%
Agent: Re-Search abgeschlossen. Score-Delta: höchster Treffer fällt von 87 auf 52. Keine Einzelreferenz kombiniert RNP + LNP + quantitative Effizienz-Schwellenwerte → Chain abgeschlossen.
Action:
Pass (conditional)
Strong differentiation via eukaryotic specificity + RNP delivery modality + quantitative thresholds.
No prior art combines these three elements. Confidence: 81%.
Human check required: spec support for amended elements ([0042], [0058], [0071], [0083]), verification of Jinek 2012 priority date chain.
| Szenario |
Stunden |
| Ohne ClaimForge |
20–28 h |
| ClaimForge Loop |
2.5 h |
| Netto-Ersparnis |
18–25 h |
Caveat: EPO oral proceedings not covered; Art. 123 added-matter check required by human attorney before filing.
- EPO oral proceedings: human attorney required if examining division maintains Art. 56 objection
- Art. 123(2) added matter: automated check flags potential issues, human verification required
- Jinek 2012 priority date: must be verified by human counsel before relying on it as closest prior art
- In vivo delivery in specific tissue types: may require additional experimental data
CRISPR / Biotech als Demo-Szenario
ClaimForge's autonomer Loop kann über den gesamten Prosecution-Workflow eingesetzt werden — von der Prior-Art-Recherche über Claim-Tree-Generierung bis zur Office-Action-Erwiderung, auch für Biotech-Patente mit komplexen molekularbiologischen Unterscheidungsmerkmalen.