While losing at the EPO, ToolGen escalates battle against Vertex in Europe

ToolGen is seeking a global licensing agreement with Vertex for the use of the world’s first genome-editing therapy, Casgevy. The Korean biotech company is now stepping up the pressure once again on Vertex and its commercial manufacturing partner, Lonza. It has filed two further lawsuits at the Unified Patent Court and the District Court The Hague.

At the UPC local division The Hague, ToolGen sued the two companies for infringement of the unitary patent EP 4 397 760. ToolGen is seeking an injunction in 18 UPC member states (case ID: UPC_CFI_0001830/2026). A UPC lawsuit had been on the cards since the dispute began in early 2025, but has only now become a reality. This brings the total number of cases before the European court involving biotechnologically produced therapies to one more. This year, several mRNA cases are at the centre of UPC proceedings.

In the Netherlands, the ToolGen filed a lawsuit based on EP 4 342 987. Both patents are recently granted divisional patents. They belong to the same family as EP 4 357 457, which is already the subject of proceedings in the UK, the Netherlands and at the EPO.

ToolGen has also challenged Vertex’s Casgevy therapy in the District of Massachusetts, alleging infringement of its US Patent No. 12,473,559.

Million-dollar business

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. In the past, media reports put the cost of the one-time treatment at approximately $2.2 million.

The expansion of its legal actions in Europe “demonstrates ToolGen’s commitment to obtaining fair compensation for the unauthorised use of its valuable, and growing, patent portfolio directed at foundational CRISPR RNP technology,” a company spokesperson says.

ToolGen reiterated once again that, in implementing its enforcement strategy, its aim is not to limit or delay patient access to Casgevy or other genome-editing therapies, but to ensure appropriate recognition and compensation for the use of ToolGen’s foundational technology.

The UK and Dutch cases

In early 2025, the Korean company filed a claim in the UK High Court regarding infringement of its EP 457 (case ID: HP-2025-000013). ToolGen is seeking an injunction.

Meanwhile, Vertex and Lonza went on the offensive in the UK and filed a revocation action against EP 457, as well as against the two divisional applications EP 987 and EP 760 (case ID: HP-2026-000004). JUVE Patent has learnt that the UK High Court will hear these claims together with ToolGen’s original claim in November 2026.

In the Netherlands, it was Vertex who went on the offensive first. In February 2025, Vertex filed a nullity suit against EP 457 at the District Court of The Hague (case ID: C/09/689657). At that time, Vertex anticipated an infringement claim by ToolGen against Lonza’s production of Casgevy at its Dutch facility.

In September 2025, ToolGen’s challenge to the production of Casgevy in the Netherlands came to pass (case ID: C/09/691064 25/765).

Setback at the EPO

ToolGen’s EP 457 thus plays a central role in the first wave of litigation surrounding Casgevy. Last week, an opposition division of the EPO, presided over by judge Giovanni Macchia, revoked the patent. The opposition division had scheduled the hearing for 27 to 29 May, but reached its decision after just one day.

It is considered certain that ToolGen will now lodge an appeal against the decision with the Boards of Appeal. However, this could now delay ToolGen’s older infringement suits in the UK and the Netherlands. But the EPO’s decision has no impact on the recent lawsuits.

Vertex had 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 man claims.

The advisers

The Düsseldorf-based patent attorney firm König Szynka von Renesse drafted ToolGen’s patent applications, with Lars Hemsath taking responsibility. In early 2025, the firm joined forces with Hoffmann Eitle, which has been registered as ToolGen’s EPO representative since then.

Hoffmann Eitle works closely with Potter Clarkson on the matter. ToolGen filed the UK suit and now the UPC case via a mixed team from Potter Clarkson. Lawyer Oliver Laing leads the cases, with Mark Didmon heading the patent attorneys on technical matters.

In the Netherlands, the patent team at BarentsKrans, led by partner Jaap Bremer, is handling the cases. The patent team at this Dutch full-service law firm is based in The Hague and specialises in litigation concerning pharmaceutical patents, particularly for generic drug companies.

Freshfields or Carpmaels?

On the defendant’s side, it is not yet known who will lead the proceedings at the UPC and the District Court of The Hague. The claims are currently being served.

In the UK proceedings, Kirkland & Ellis partner Daniel Lim leads Vertex’s defence team. He has a strong reputation for CRISPR-Cas cases. However, the firm does not have a patent team on the continent. Its London patent litigators are also not admitted to the UPC.

A team from Freshfields’ Amsterdam office led by partner Rutger Kleemans represents Vertex and Lonza in the Dutch proceedings. It would be a surprise if it were not also instructed to defend the latest claim in the Netherlands.

Freshfields also maintains a strong presence at the UPC with an international team. The same applies to the patent litigation team of Vertex’s EPO advisers, Carpmaels & Ransford. They are therefore likely to be shortlisted for the defence at the UPC.