James Warner


James leads the Pharmaceuticals team at Carpmaels & Ransford and “is well-known for handling multi-opponent oppositions, including rare cases with more than 10 opponents” (IAM1000). His practice focuses exclusively on medicinal chemistry inventions for pharmaceutical innovators and he has acquired a reputation for his imaginative approaches to the legal and technical strategies on the most commercially important cases. James has over 20 years’ experience in conducting multi-opponent European Patent Office (EPO) opposition proceedings – he is one of only a handful of advocates to have extensive first chair experience of defending EPO oppositions with large numbers of opponents and has over ten opposition defences of eight or more opponents on his CV. He brings practical experience of the subtle interactions of patent, supplementary protection certificate and regulatory law to these commercial situations.

Individually recommended in industry directories, James is “trusted by a number of well-known pharmaceutical companies” (JUVE Patent), and is particularly known for successfully prosecuting and defending NCE, combination, formulation, second medical use and dosage regimen patents on marketed products. In this sphere, he has advised on many of Novartis’ blockbuster products and has led numerous EPO opposition defences to generic challenges, most notably the multi-party oppositions against Novartis’ Entresto, Exforge, Glivec, Aclasta, Ultibro and Jakavi products. He is also the lead European outside patent counsel for Gilead’s HIV and HBV portfolios, successfully defending Gilead’s TAF and cobicistat medicines, present in a variety of their blockbuster antiviral products, against multi-opponent oppositions. He represents Roche in EPO opposition and appeal proceedings and is a lead counsel for Janssen’s small molecule portfolio, and is currently representing Janssen on the most opposed (and defended) European patent in the EPO’s history (20 opponents).

James’ EPO opposition work frequently brings him into contact with parallel national litigation, and he is particularly sought out to bring his EPO and technical experience to litigation strategies throughout Europe and the world. He has earned a particular reputation defending cases involving clinical trial disclosures, and has represented, or is representing, patent proprietors in many of the leading cases in this space, particularly T239/16, T108/21 and T1098/22.

James has a great deal of experience representing before the EPO’s Enlarged Board of Appeal, having prosecuted two petitions for review and currently representing Novartis before the Enlarged Board of Appeal on the questions around the EPO’s competence to examine the transfer of priority rights and the validity of the joint applicant’s approach (G1/22).

James, despite being a busy partner, always has time for our questions and personally communicates with us regularly.
Legal 500 2022


  • MChem (University of Oxford)
  • Chartered Patent Attorney
  • European Patent Attorney
  • Intellectual Property Litigation Certificate

Key Cases

  • Lead counsel for Novartis for many of their blockbuster products, in multiple opposition with multiple opponents, e.g. Entresto®, Exforge®, Glivec®, Aclasta®, and Ultibro®. E.g. T239/16, T403/18, T1098/22, T345/17, T741/23, T31/18, T263/14, T507/17 (combinations, formulations, second medical uses, co-crystals, salts, polymorphs and clinical trial inventions).
  • Lead counsel for Gilead for their HIV (e.g. Genvoya®) and HBV (e.g. Vemlidy) portfolios against multiple opponents in multiple EPO opposition proceedings – E.g. T2200/17, T1214/18 (new chemical entities, salt forms and combination products).
  • Lead counsel for J&J on numerous products, including the opposition defences on the dosage regime patents for Xeplion® (20 opponents) and Trevicta®/Trinza® (8 opponents)
  • Lead counsel for Roche, including T2035/22 (new chemical entities) and T562/20 (patient sub-groups).