James Warner


James leads the Pharmaceuticals team at Carpmaels & Ransford. His practice focuses exclusively on medicinal chemistry inventions for pharmaceutical innovators and has a reputation for his imaginative approaches to legal and technical strategies on the most commercially important cases. His work is inevitably contentious in nature and he has over 20 years’ experience in conducting multi-opponent European Patent Office (EPO) opposition proceedings. James is one of only a handful of advocates to have first chair experience of defending EPO oppositions with more than eight opponents and to date has been instructed on ten opposition defences of this size. He brings practical experience of the subtle interactions of patent, supplementary protection certificate and regulatory law to these commercial situations.

Individually recommended in MIP and IAM Patent 1000, and noted as “excellent” by Legal 500, James 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 most of Novartis’ blockbuster products and has led numerous EPO opposition defences to generic challenges, most notably the multi-party oppositions against Novartis’ Entresto (valsartan/sacubitril), Exforge (valsartan/amlodipine), Glivec (imatinib), Aclasta (zoledronate), Ultibro (indacaterol/glycopyrronium) and Jakavi (ruxolitinib) 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. James recently successfully defended Amgen’s patent for Otezla (apremilast) against a 15-opponent opposition.

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 reputation defending cases involving clinical trial disclosures, was involved in the leading case law in this space (T239/16) and is particularly sought out for defending cases with a similar fact pattern. He has represented before the EPO’s Enlarged Board of Appeal twice, and is currently representing in the likely referral to the Enlarged Board on the validity of the joint applicant’s approach (T1513/17).

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

Key Cases

  • Genvoya® – Gilead v multiple opponents (new chemical entities, salt forms and combination products – multiple EPO opposition proceedings)
  • Exforge® & Exforge HCT® – Novartis v eight opponents (combination product patent – EPO opposition proceedings; litigation support)
  • Glivec® – Novartis v 10 opponents (formulation patent – EPO opposition proceedings; litigation support)
  • Aclasta® – Novartis v five opponents (second medical use and new regimen patent – EPO opposition proceedings; Enlarged Board of Appeal petition for review; litigation support)
  • Jakavi® – Incyte v Actavis & Generics UK (salt patent)