ToolGen and BarentsKrans step up CRISPR battle against Vertex

The lawsuit alleges that Lonza’s production of Vertex’s Casgevy at its Dutch facility infringes ToolGen’s EP 4 357 457 patent covering CRISPR-Cas9 RNP technology. EP 457 is a divisional patent of EP 4 397 759.

Vertex, for whom Lonza manufactures the drug, had apparently anticipated this move. The company challenged EP 457 in February with a nullity action at the District Court of The Hague (case ID: C/09/689657).

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

Next strike

What Vertex had likely anticipated months ago has now come to pass: the infringement suit against Lonza’s production at the same court (case ID: C/09/691064 25/765).

ToolGen had already challenged Casgevy directly at the UK High Court in April (case ID: HP-2025-000013). The suit names Vertex’s parent company, its European company and commercial manufacturing partners Roslin Cell Therapies and Lonza Netherlands as defendants. Meanwhile, Vertex is defending itself in the UK through a validity action against EP 457.

Although ToolGen seeks an injunction against the production and sale of Casgevy in the UK and the Netherlands, CEO Jong Sang Ryu maintains that “the lawsuit is not intended to restrict patient access to life-changing therapies”.

By targeting a key European production hub, ToolGen aims to reaffirm the importance of its foundational CRISPR-Cas9 RNP technology and strengthen protection of its intellectual property rights, according to a company statement.

Patent battle with a long lead-up

Biotech companies have fought over CRISPR/Cas patents for years, primarily at patent offices around the world. Months ago, ToolGen announced it would file patent infringement suits against Vertex.

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-thalassaemia. 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.

Currently there are no other civil lawsuits between the parties outside the UK and Netherlands. However, as ToolGen seeks a global licence agreement, the Korean company may increase pressure on Vertex with further lawsuits. Although EP 457 is currently opted out, a UPC remains a possibility. Pharmaceutical and biotech companies had initially removed numerous patents from the jurisdiction of the new court. Recently, however, several of them have opted their patents back in. In particular, lawsuits concerning mRNA patents have recently been increasingly filed with the UPC. The local division in The Hague is the focus here.

BarentsKrans and Freshfields in Dutch proceedings

For a long time, it was unclear which law firm would represent ToolGen in the nullity action at the District Court in The Hague. Some firms, such as Bird & Bird and Brinkhof, were ruled out due to their involvement in EPO opposition proceedings around CRISPR Cas patents. In the end, the patent team at BarentsKrans, led by partner Jaap Bremer, secured the mandate.

The patent team of the Dutch full-service law firm is based in The Hague and has a strong focus on litigation regarding pharma patents, especially for generic drug companies such as Viatris. It now represents ToolGen in both the infringement action and the nullity action.

Senior associate Jarieke Timmerman and associate Maurits Tol complete the BarentsKrans team. René Ragders, patent attroney from Dutch firm AOMB, is advising on the technical aspects of the case.

Lonza’s lawyers in the Dutch infringement action have not yet been confirmed. However, it would be surprising if they did not come from Freshfields. A team from Freshfields’ Amsterdam office led by partner Rutger Kleemans filed the related nullity suit. Associate Allard van Duijn provides support.

Battle in the UK and at the EPO

In the UK proceedings, Kirkland & Ellis partner Daniel Lim leads Vertex’s defence team. He has a strong reputation for CRISPR Cas cases.

ToolGen filed the suit via a mixed team from Potter Clarkson. Lawyer Nick McDonald leads the case, with Mark Didmon heading the patent attorneys on technical matters. The mixed firm has a strong reputation in UK life sciences patents.

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

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. Grund IP and Vossius & Partner are also challenging the patent grant through straw man claims. Vossius has previously represented CRISPR Therapeutics in EPO oppositions against ToolGen.

Düsseldorf patent attorney firm König Szynka von Renesse drafted ToolGen’s patent applications. The firm joined forces with Hoffmann Eitle at the beginning of 2025, which is now registered as ToolGen’s EPO representative. Hoffmann Eitle works closely with Potter Clarkson on the matter.