Korean biotech company ToolGen has initiated patent infringement lawsuits against Vertex Pharmaceuticals over Casgevy, the world's first approved CRISPR gene therapy, marking a significant escalation in the ongoing battle over fundamental genome editing patents. The company filed suit in the UK High Court in April 2025, targeting Vertex and its manufacturing partners Lonza and RoslinCT.
CRISPR Patent Dispute Reaches Civil Courts
ToolGen's legal action represents a shift from traditional patent office disputes to civil litigation, focusing on what the company claims is unauthorized use of its proprietary CRISPR RNP (Ribonucleoprotein complex) technology. The Korean company has secured patents for this technology worldwide, including in Europe under patent EP 4 357 457.
"Vertex's CASGEVY was born from ToolGen's proprietary CRISPR RNP technology," stated ToolGen CEO Jong Sang Ryu. "As the company behind the world's first CRISPR Cas9-based gene therapy, we believe Vertex should fairly recognize ToolGen's contribution through appropriate licensing."
Casgevy's Commercial Success and Market Impact
Casgevy became the world's first genome editing therapy to receive marketing authorization, starting with UK approval in November 2023, followed by European Commission approval in February 2024 and subsequent US approval. The therapy provides a novel treatment for patients with sickle cell disease and beta-thalassemia, two serious blood diseases.
The one-time treatment carries a price tag of approximately £1.7 million ($2.2 million USD), with sales projections indicating blockbuster potential. The therapy uses CRISPR/Cas9 technology to modify patients' stem cells to produce functional rather than defective hemoglobin.
Strategic Legal Maneuvering
In response to ToolGen's announced legal action, Vertex preemptively filed a nullity suit against EP 4 357 457 in the Netherlands in February 2025. The Netherlands was chosen strategically as it is where Casgevy therapy is produced, and Dutch patent courts have recently shown a tendency to invalidate patents.
Vertex's defense team is led by Kirkland & Ellis partner Daniel Lim, who has extensive experience in CRISPR/Cas patent proceedings. ToolGen has assembled a team from Potter Clarkson, with lawyer Nick McDonald leading the case and Mark Didmon heading the patent attorneys on technical matters.
Technology at the Center of Dispute
ToolGen's CRISPR RNP technology represents what the company describes as a groundbreaking method that delivers the Cas9 protein directly into cells in its protein form. According to ToolGen, this approach avoids cellular toxicity often associated with DNA- and mRNA-based systems and eliminates the risk of foreign DNA integration into the genome. The technology reportedly provides significantly lower off-target effects and superior safety profiles.
Licensing Objectives and Patient Access
ToolGen emphasized that the lawsuit "is not aimed at restricting patient access to CASGEVY in the United Kingdom." Instead, the company seeks to secure a worldwide license agreement through the litigation, indicating its primary goal is proper recognition and compensation for its technology rather than blocking patient access to the therapy.
The legal battle occurs against the backdrop of Vertex's December 2023 licensing agreement with Editas Medicine for CRISPR genome editing technology. Editas holds exclusive licenses to various CRISPR/Cas patents from institutions including Harvard Institute, The Broad Institute, and the Massachusetts Institute of Technology.
Broader Patent Landscape
The dispute reflects the complex patent landscape surrounding CRISPR technology, with various researchers, institutes, and companies contesting basic patents for CRISPR/Cas and related applications. Multiple parties have challenged ToolGen's patent family through opposition proceedings at the European Patent Office, including Vertex through Carpmaels & Ransford, as well as challenges from Grund IP and Vossius & Partner.
As ToolGen seeks a global license agreement, the Korean company may expand its legal pressure on Vertex with additional lawsuits in other jurisdictions, with the Unified Patent Court remaining a possibility for future action.
