Context: CRISPR-Cas9 drugmakers Vertex Pharmaceuticals, Lonza, and Roslin Cell Therapies (RoslinCT) challenged ToolGen’s EP4357457 (“Composition for cleaving a target DNA with a guide RNA specific for the target DNA and a nucleic acid encoding a Cas protein or a Cas protein itself, as well as the use thereof”) in three separate filings between October 2024 and March 2025 (European Patent Register). They claimed that the subject matter of the patent is not patentable and goes beyond the content of the application as originally filed.
What’s new: ToolGen has sued Vertex, Lonza, and RoslinCT in the High Court of Justice for England & Wales (EWHC) over the infringement of EP4357457 (Case No. HP-2025-000013).
Direct impact and wider ramifications: ToolGen’s lawsuits do not come as a surprise, given the company is likely eager to maintain its leading position in the CRISPR field. It will be interesting to see whether or not it will be able to defend its growing corner of the market, which is still in its early days and could be anyone’s game. ToolGen has recently celebrated some significant victories in patent oppositions, including when an anonymous company challenged its AU2013335451 in Australia’s Patent Office and, after successfully amending the patent’s claims, the Federal Court of Australia allowed it to proceed to grant.
South Korea-based ToolGen is a leading gene editing company known for its CRISPR-Cas9 system. It holds over 80 European patents in the field of CRISPR gene editing, including EP4357457, which was granted by the European Patent Office (EPO) in September 2024. That patent was the very first European patent it secured for a CRISPR-Cas9 protein delivery method (October 22, 2024 BusinessKorea).
RoslinCT, Vertex and Lonza all use CRISPR-Cas9 gene editing technology to discover, develop and market new treatments for genetic diseases like sickle cell disease and beta-thalassemia.
Vertex’s patent opposition, filed by Carpmaels & Ransford LLP’s Cameron Marshall on February 28, argued that the “claims go beyond the content of the application as filed and that, anyway, they lack priority basis and so lack novelty and/or inventive step”. It also claimed that EP4357457 is a second-generation application filed from EP3372679 (“Composition for cleaving a target dna comprising a guide rna specific for the target dna and cas protein-encoding nucleic acid or cas protein, and use thereof”), which was a first-generation divisional of the original PCT application. Vertex added:
“The granted claims were all included in the second-generation divisional at the time of filing, but none of them finds basis in either the original PCT application (grandparent) or in the first-generation divisional application (parent), so the claims do not meet the requirements of Article 76(1) EPC.”
The first opposition was filed by Vossius & Partner’s Dr. Hans-Rainer Jaenichen, upon publication of the patent’s grant. This indicates that the firm was monitoring the examination process and filed an already-prepared opposition notice on the very date the grant was made public.
The most recent patent opposition was filed by Grund IP’s Dr. Martin Grund. All three firms also requested oral proceedings in case the EPO’s Opposition Division is inclined not to revoke the patent in question.
At the heart of the patent-in-suit is ToolGen’s Ribonucleoprotein (RNP), a technology that directly delivers the Cas9 protein to cells, preventing the insertion of foreign genes and reducing cellular toxicity. This technology is widely implemented in both plant and animal gene editing, and drug development, and is allegedly used in Vertex’s Casgevy drug – a treatment for hereditary rare diseases, such as sickle cell disease and beta-thalassemia. Casgevy first received European marketing authorization in February 2024 and costs $2.2 million per course of treatment.
ToolGen’s suit, which was filed on April 15 by Potter Clarkson LLP, is not aimed at restricting the use of Casgevy by UK patients but to obtain “fair compensation” for its technology, the plaintiff has stated. The company’s CEO Yoo Jong-sang further said Casgevy from Vertex was born using ToolGen’s CRISPR RNP technology and the company “expects Vertex to acknowledge the use of ToolGen’s CRISPR gene editing and CRISPR RNP technology to create this innovative treatment and pay a fair price for it.”