ToolGen and Vertex focus battle over CRISPR/Cas therapy Casgevy in Europe

Biotech companies have fought over CRISPR/Cas patents for years, primarily at patent offices around the world. Now the technology has reached civil courts. Months ago, Korean biotech company ToolGen announced it would file patent infringement suits against Vertex. ToolGen is targeting the first therapy using CRISPR/Cas technology.

Casgevy became the world’s first genome editing therapy to receive marketing authorisation, starting with the UK in November 2023, followed by European Commission approval in February 2024. The US has also approved Casgevy.

The therapy provides a novel treatment for patients with two serious blood diseases: sickle cell disease and beta-thalassemia. The drug uses CRISPR/Cas9 to modify patients’ stem cells to produce functional rather than defective haemoglobin.

Media reports put the cost of the one-time treatment at approximately $2.2 million. In December 2023, Vertex entered into a licensing agreement with Editas Medicine for CRISPR genome editing technology. Editas is an exclusive licensee of various CRISPR/Cas patents, including from Harvard Institute, The Broad Institute, and the Massachusetts Institute of Technology.

Pre-emptive strike in the Netherlands

After ToolGen announced legal action at the end of last year, Vertex went on the offensive and filed a nullity suit against EP 4 357 457 in the Netherlands. EP 457 is a divisional patent of EP 4 397 759.

Dutch patent courts have recently shown a tendency to invalidate patents. Moreover, the Netherlands is where Casgevy therapy is produced.

Although Vertex filed the lawsuit in February, few details have emerged. However, JUVE Patent has learned that a team from Freshfields’ Amsterdam office led by partner Rutger Kleemans filed the nullity suit. Associate Allard van Duijn provides support.

It is not yet known which Dutch law firm ToolGen has instructed to defend the patent. However, several law firms may be conflicted due to their involvement in EPO opposition proceedings concerning CRISPR/Cas patents. For example, Koen Bijvank from Brinkhof is very active here for The Broad Institute, as is the UK team from Bird & Bird. A pure patent litigation team from a Dutch firm is therefore a likely choice.

Main strike in UK

ToolGen believes Vertex’s therapy Casgevy infringes its EP 457 and filed an action at the UK High Court in April (case ID: HP-2025-000013). ToolGen seeks an injunction but CEO Jong Sang Ryu stated the lawsuit “is not aimed at restricting patient access to Casgevy in the United Kingdom”.

Jong Sang Ryu said, “Vertex’s CASGEVY was born from ToolGen’s proprietary CRISPR RNP technology. As the company behind the world’s first CRISPR Cas9-based gene therapy, we believe Vertex should fairly recognise ToolGen’s contribution through appropriate licensing.” This indicates ToolGen aims to secure a worldwide licence agreement through the lawsuit.

The suit names Vertex’s parent company, its European company, and commercial manufacturing partners Roslin Cell Therapies and Lonza Netherlands as defendants. Kirkland & Ellis partner Daniel Lim leads Vertex’s defence team.

Lim was involved in CRISPR/Cas patent proceedings early on and observed procedures at the European Patent Office. Associates Alex Magnusdottir and Ray Cheng complete the Kirkland team. The law firms representing Lonza and Roslin are not yet known.

ToolGen filed the suit via a mixed team from Potter Clarkson. The firm has a strong reputation in UK life sciences patents and maintains both a renowned patent attorney practice and a nine-strong litigation team. Lawyer Nick McDonald leads the case, with Mark Didmon heading the patent attorneys on technical matters. Lawyer Oliver Laing and patent attorney Matthew Walsh provide support.

Potter Clarkson is also involved in CRISPR/Cas patent disputes at the EPO through its own straw man claim against The Broad Institute.

Battle at the EPO

Vertex will certainly defend itself in the UK with a counterclaim for revocation against EP 457. Currently there are no civil lawsuits outside the UK and Netherlands. However, as ToolGen seeks a global licence agreement, the Korean company may increase pressure on Vertex with further lawsuits. The UPC also remains a possibility.

Various researchers, institutes and companies have long contested basic patents for CRISPR/Cas and related use patents. Some involve grant proceedings concerning the ToolGen patent family. Vertex challenged the grant of EP 457 via Carpmaels & Ransford, led by partner Cameron Marshall. Grund IP and Vossius & Partner are also challenging the patent grant through straw men claims. Vossius partner Hans-Rainer Jaenichen has previously represented CRISPR Therapeutics in EPO oppositions against ToolGen.

Düsseldorf patent attorney firm König Szynka von Renesse drafted ToolGen’s patent applications, with Lars Hemsath taking responsibility. The firm recently joined forces with Hoffmann Eitle, which is now registered as ToolGen’s EPO representative. Hoffmann Eitle works closely with Potter Clarkson on the matter. In Germany, ToolGen also collaborates with Jones Day.