BioTech IP Review

Cas9/RNA Complexes for Inducing Modifications of Target Endogenous Nucleic Acid Sequences

  • Assignee / Owner: ToolGen, Inc. (South Korea–based genome editing technology company)
  • Patent Number: 12,473,559
  • Filed: (continuation framework dating back to earlier applications; priority filings from 2020/2023)
  • Patent Issued: November 18, 2025
  • Title: Cas9/RNA Complexes for Inducing Modifications of Target Endogenous Nucleic Acid Sequences in Nucleuses of Eukaryotic Cells

What It Covers

This patent protects foundational next-generation CRISPR-Cas9 ribonucleoprotein (RNP) technology that has direct importance for therapeutic genome editing:

Core Invention
  • It claims compositions and methods for assembling CRISPR-Cas9 RNP complexes — combining Cas9 protein (with a nuclear localization signal) and a single-guide RNA (sgRNA) — to induce targeted gene edits in the genome of eukaryotic cells (including human cells).
  • The technology covers pre-complexing the Cas9 protein and guide RNA outside the cell, then delivering the RNP directly into cells (for example, via electroporation), where it induces precise genomic modifications.
Key Technical Elements
  • Cas9 Protein with Nuclear Localization Signal (NLS): Enables efficient entry into the nucleus of target cells.
  • Chemically Synthesized sgRNA: Combines a CRISPR RNA (crRNA) and trans-activating crRNA (tracrRNA) that guide the Cas9 to the precise genomic target.
  • Defined RNP Stoichiometry: The issued patent covers methods specifying high-precision molar ratios for RNP assembly and delivery to optimize editing efficiency and reduce off-target effects.

Why It’s Important

1. Direct relevance to CRISPR therapies

This RNP delivery technology is used in clinical and ex vivo gene editing workflows, including therapies like Casgevy (exagamglogene autotemcel) — the first approved CRISPR-based therapy for sickle cell disease and β-thalassemia.

2. Global strategic reach

ToolGen’s patent strengthens its global IP portfolio by securing U.S. rights to an RNP platform already covered in Europe, Asia, and other jurisdictions — a critical asset for licensing negotiations or enforcement against major biotech products.

3. Foundation for future clinical use

Direct delivery of Cas9 RNP (rather than DNA or mRNA) shortens intracellular editing times, reduces off-target edits, and improves safety — enhancing the clinical attractiveness of CRISPR therapeutics across a range of diseases.

4. Commercial leverage and litigation

ToolGen has initiated litigation based on this patent in the U.S. to enforce its rights against sophisticated CRISPR therapy developers — highlighting its perceived commercial value.

Summary

U.S. Patent No. 12,473,559, issued November 18, 2025 to ToolGen, Inc., covers advanced CRISPR-Cas9 RNP complexes and their delivery methods for inducing precise genomic edits in eukaryotic cells. Because such RNP delivery technologies are central to many therapeutic CRISPR applications (including the manufacturing of approved therapies like Casgevy), this patent is one of the most lucrative and strategically important CRISPR-related patents of 2025, underpinning commercial and clinical value in the gene-editing therapeutics space.

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