BioTech IP Review

Publication Number: US 20250361528 A1
Filing Date: December 22, 2022
Publication Date: November 27, 2025
Applicant/Assignee: Sangamo Therapeutics, Inc.
Inventors: Friedrich A. Fauser, Jeffrey C. Miller, Sebastian Arangundy

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What This Patent Covers

This patent application describes advanced base editor systems that combine Sangamo’s proprietary zinc finger protein (ZFP) domains with cytidine deaminase domains to create fusion proteins capable of precise single‑base editing in DNA:

Zinc Finger‑Based Base Editors
The invention provides systems in which a ZFP domain — engineered to bind a specific DNA sequence — is fused to a cytidine deaminase domain (or fragments thereof) that can catalyze conversion of cytosine (C) to uracil (U), which can then be replaced by thymine (T) during DNA repair. Multiple fusion formats are described, including pairs of proteins that dimerize upon binding their targets.

Broader Gene Editing Capabilities
These base editor systems enable precise single‑base changes without creating double‑strand breaks, which reduces the risk of unwanted genomic alterations compared to traditional nuclease‑based editing. The system can be adapted for multiplex editing, enabling several targets to be edited in parallel.

Delivery Formats
The application also contemplates expressing the fusion proteins from nucleic acid constructs, including packaging them into viral vectors (like AAV or lentivirus) for in vivo delivery to patient cells — an important feature for therapeutic genome editing.

Methods and Uses
Methods of using these base editors include correcting disease‑causing point mutations, inducing knock‑outs by creating stop codons, or otherwise altering regulatory regions to up‑ or down‑regulate gene expression. Such precise editing has applications across a range of genetic diseases, rare disorders, or other conditions where point mutations are causal.

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Why This Patent Is Important

1) Core Platform Innovation
Sangamo’s zinc finger platform — one of the earliest and most deeply developed gene‑editing technologies — is central to the company’s value proposition in genomic medicine. This base editor patent protects next‑generation editing tools that can correct single nucleotide mutations, which are implicated in many monogenic disorders.

2) Therapeutic Breadth & Market Potential
Precise base editing could be used to treat a wide variety of genetic diseases (e.g., hemophilia, Fabry disease, ALS, Huntington’s, rare pediatric disorders), each representing multi‑billion‑dollar markets if effective therapies are developed. The flexibility of base editing makes it a strong platform for multiple product candidates.

3) Strategic IP Position
Owning patents on foundational base editor compositions and systems — rather than only product‑specific inventions — gives Sangamo broad intellectual property leverage. This strengthens bar­riers to entry, supports licensing opportunities, and enhances negotiation power in collaborations or partnerships.