Jennifer Antcliff


Jenny is a partner in the firm’s Dispute Resolution team, ranked as a Next Generation Partner by Legal 500 (2024, 2023) and an Up and Coming Partner by Chambers & Partners (2023). Her patent litigation expertise focusses on biotechnology and pharmaceutical products, including blockbuster small molecule drugs, therapeutic antibodies and orphan medicines. According to Legal 500 (2023), Jenny is “one of the best patent litigators in London”.

Jenny has litigated before the UK Patents Court, the Court of Appeal and the Supreme Court, most notably the Eli Lilly v Human Genome Sciences cases, and the Warner-Lambert v Actavis (“pregabalin”) litigation. Jenny has since represented FibroGen against Akebia in a further significant and successful appeal to test the boundaries of UK law on sufficiency (Impact Case of the Year, MIP 2022).

Jenny also specialises in complex SPC litigation and associated regulatory advice, many cases involving references to the CJEU or EFTA Court, including C-493/12 Eli Lilly v Human Genome Sciences, E-16/14 Pharmaq v Intervet, C-577/13 Actavis v Boehringer Ingelheim, C-443/17 AbraxisBioscience and, most recently, Teva v Janssen Pharmaceutica (Xeplion®). Jenny was awarded SPC Litigator of the Year at the LMG Life Sciences Awards (EMEA) in 2023 and 2022.

As a “highly skilled patent litigator with an extensive knowledge of the pharmaceutical industry” (Chambers & Partners, 2022) Jenny increasingly assists her clients in this sector with cross-border patent and SPC litigation matters, working closely with the business and external advisers to align launch or enforcement strategies across Europe.

The Legal 500 also cites that “Clients also praise “excellent litigator” Jennifer Antcliff, who focuses on biotechnology and pharmaceutical patent litigation and “is already a star and has a phenomenal future ahead of her”. (Legal 500, 2020)

Jenny joined Carpmaels & Ransford from her role as IP Litigation Counsel at Actavis/Allergan, where she handled high-profile patent cases such as Actavis v ICOS (tadalafil) and the LYRICA® (pregabalin) litigation – the first case before the UK Courts in which infringement of a second medical use patent was put in issue. Actavis successfully resisted an interim injunction and any findings of infringement at trial.

Jenny trained and qualified at a magic circle firm after obtaining а first class honours degree in biochemistry from Imperial College, London, and а doctorate in molecular and structural biology from the University of Oxford.

“an incredibly talented lawyer with a wealth of experience in advising on European litigation strategy and coordinating multi-jurisdictional complex disputes in the pharmaceutical and biotechnology space. She has a strong scientific and technical knowledge and is great at ensuring that all the details of a case are thoroughly investigated. Jennifer is also strategic, pragmatic and knows how to gracefully move a case forward.”
IAM Patent 1000, 2024


  • BSc Biochemistry (Imperial College London)
  • DPhil (PhD) Molecular & Structural Biology (University of Oxford)
  • Diploma in IP Law & Practice (University of Oxford)
  • Solicitor
  • UPC Representative

Key Cases

  • Janssen, Pfizer, Regeneron v Amgen (bispecific antibodies – High Court)
  • Anti-CGRP antibodies for treating migraine – defence of key patent against competitors
  • Human Genome Sciences v Eli Lilly (mAbs/plausibility – Supreme Court & Court of Appeal)
  • Akebia, GSK v FibroGen (sufficiency of therapeutic use claims – High Court, Court of Appeal; Impact Case of the Year, MIP 2022)
  • Warner-Lambert v Actavis (plausibility/skinny label enforcement – High Court, Court of Appeal)
  • Accord v Celgene (Revlimid® – High Court)
  • Teva v Janssen Pharmaceutica (SPCs for prodrugs – High Court)
  • C-443/17 Abraxis Bioscience v Comptroller General of Patents (SPCs, Article 3(d) – CJEU)
  • C-493/12 Eli Lilly v Human Genome Sciences (SPCs, Article 3(a) – CJEU)