Kirkland & Ellis

Firm overview:

Arguably the biggest force in patent litigation in London, Kirkland & Ellis is widely considered to be a top-tier firm—they’re “outstanding”, says an industry peer. In less than a decade, the UK patent practice of the world’s highest-grossing law firm has propelled itself from greenfield project to market leader. The London team maintains a strong transatlantic connection with colleagues in the US, working as one formidable unit on global disputes and non-contentious patent matters. Clients rely on the team for straight-talking advice when faced with critical decisions over key IP.

“They litigate cases to the nth degree,” comments a competitor, who also admits that Kirkland’s market share of contentious patent work is “impressive”. The team relishes a challenge and takes on the most challenging cases that have failed elsewhere. Kirkland litigators are known for their extremely thorough preparation for hearings, with a relentless focus on detail and armoury of creative solutions that push the boundaries of patent law.

“They’re kind of everywhere, and not in a negative way,” comments another industry counterpart, although the team’s rise to prominence is also attributed to “a certain kind of aggressive style”. Kirkland has been particularly active in the flurry of high-profile technology and telecoms standard-essential patents cases in the UK, often acting for the company that wants a FRAND licence such as Lenovo in its dispute with Ericsson.

Team overview:

“They have a healthy caseload, and that’s reflected in the number of people doing the work,” says a competitor of Kirkland’s London patent team. Junior lawyers become partners at the firm earlier than at more traditional boutiques, with the team handling multiple high-profile matters for prestigious clients.

A peer credits Nicola Dagg with building “this amazing market-leading team from zero … it’s incredible”. Described as a “force to be reckoned with”, and an “an exceptional lawyer”, Dagg is considered one of the best patent litigators in Europe. Her practice covers standard essential patent (SEP) and FRAND disputes, and her extensive experience also includes blockbuster small molecule litigation against generic companies, biologies and biosimilar litigation, vaccines, diagnostics and gene therapies.

Also a stand-out litigator at the firm, Oscar Robinson has acted in many of the major FRAND disputes before the High Court, Court of Appeal and UK Supreme Court in recent years. He also draws on his background in biological sciences to handle life sciences litigation.

Daniel Lim has a broad practice that covers a wide range of technical fields. As well as UK litigation, Lim is regularly called upon to assist clients in multi-jursidictional disputes at a pan-European and global scale.

Key matters:

• Lenovo v Ericsson

Partners Nicola Dagg, Jin Ooi, Peter Pereira, Oscar Robinson, and associates Ashley Grant and Andrew Marks were on the Kirkland & Ellis team representing Lenovo in its high-profile FRAND dispute with Ericsson.

In February 2025, the UK Court of Appeal handed a victory to Lenovo, finding that Ericsson had breached its obligation of good faith despite Lenovo’s efforts to enter into a licence on FRAND terms.

“As this very important Court of Appeal judgment states, this behaviour by Ericsson is ‘hold up’,” Dagg told WIPR at the time.

• Panasonic v Xiaomi and Oppo

Kirkland & Ellis represented Xiaomi in a telecommunications patent dispute with Panasonic. In October 2024, judges at the Court of Appeal in England and Wales sided with Xiaomi, granting its request for an interim licence declaration and criticising Panasonic for acting in bad faith.

“The court has condemned Panasonic’s conduct as being inconsistent with its obligations under the European Telecommunications Standards Institute (ETSI) rules and its undertakings to the English Court to enter into the global FRAND licence terms to be determined by the English Court,” the Kirkland team said at the time.

• Success for Intel in semiconductor dispute

Intel secured a win against US competitor R2 Semiconductors in the UK High Court in August 2024, halting an injunction that could have barred the sale of some Intel chips.

Judges found R2’s patent invalid for lack of inventive step. The dispute also spanned the US, France and Italy.

Kirkland & Ellis represented Intel in the matter.

• Successful defence of Astellas Pharma patent for blockbuster cancer drug

Kirkland client Astellas Pharma successfully defended the patent for its blockbuster prostate cancer drug Xtandi in the UK High Court in October 2024.

The court dismissed challenges from Accord Healthcare, Sandoz, and Teva, who sought to invalidate the patent and clear the way for generic versions of the treatment.

Astellas highlighted the win as a major advancement in cancer treatment and patient care.

Clients:

Astellas, Intel, Lenovo, Xiaomi