Mark Chacksfield QC

CALL: 1999 (England & Wales 1999, Ireland 2021) | SILK: 2019
Mark Chacksfield QC
Formerly a sector leading IP junior, having taken silk in 2019 Mark is now forging an impressive reputation as an innovative and responsive silk in complex pharmaceutical, biopharmaceutical and telecoms patent actions.

Mark has appeared in many of the leading patent cases over recent years, where he has a stellar reputation, but also attracts a loyal following across the entire range of IP and media cases.

He is praised for his deep understanding of the law, innovative and inventive mind, and his impressive work ethic.

  • Experience

    Patents & SPCs

    • Optis Cellular Technology LLC v Apple Retail [2021] EWHC 1739 (Pat): this was a further successful patent validity and  infringement claim brought against Apple in Optis’ ongoing litigation. In particular Mark ran and defended against the potentially enormously important novel ‘estoppel’ defence advanced by Apple, to the effect that the alleged ‘late’ declaration by Optis’ forerunner in title barred Optis from enforcing its patent rights in the UK.
    • Vestel Elektronik v Access Advance LLC [2020] EWCA Civ 440, [2021] 4 W.L.R. 60, [2021] F.S.R. 28: this jurisdictional appeal involved a novel attempt by an implementer of the HEVC/H.265 standard to bring a claim for a FRAND declaration against the administrator of a patent pool and a patentee therewithin.
    • Optis Cellular Technology LLC v Apple Retail [2020] EWHC 2746: a successful patent validity and infringement claim brought against Apple, and potentially opening the door to a FRAND determination in a claim publicly valued by Apple as being worth up to US$8 billion.
    • Pfizer v F Hoffmann-La Roche AG [2019] EWHC 1520, [2019] RPC 14: this case remains unique as the first successful defence by a patentee of an ‘Arrow’ declaration. Involving extensive questions of the law of declaratory relief and also of Belgian practice and procedure, the Court for the first time held that no declaration should be granted, and therefore refused to opine on the underlying technical issues.
    • Actavis Group PTC EFH v ICOS Corp [2019] UKSC 15, [2020] 1 ALL E.R. 213, [2019] RPC 9: the leading Supreme Court decision considering the correct approach to obviousness in UK law.
    • Eli Lilly v Genentech [2019] EWHC 387, [2019] WLUK 15: described by Arnold J as one of the most complex patent cases he had ever tried, this biopharmaceutical infringement/validity action involved 24 reports from 9 experts running to close to 700 pages.  Its focus was on the treatment of rheumatoid arthritis and psoriasis using inhibitory antibodies to the interleukin IL-17A/F, and infringement by Lilly’s ixekizumab MAb product.  See also the parallel SPC decision [2019] EWHC 388, [2019] 3 WLUK 4.
    • Technetix v Teleste [2019] EWHC 126 (IPEC), [2019] F.S.R. 19: an IPEC validity and infringement action notable for both being the first attempt to introduce into the UK a Formstein/ensnarement defence to infringement by equivalents, and also for being a case in which Mark’s client, the Defendant, was successful having chosen not to call their own evidence in the light of the cross examination of the Claimant’s expert.
    • Chugai Pharmaceutical Co Ltd v UCB Pharma SA [2018] EWHC 2264 (Pat), [2018] 8 WLUK 232: a claim for substantial royalties under a biopharmaceutical patent licence, the resolution of which required the defence of an infringement claim of a US patent run under US patent law.
    • Fujifilm Kyowa Kirin Biologics Co Ltd v AbbVie Biotechnology [2017] EWHC 395 (Pat): the first ‘Arrow declaration’ case to have come to trial, paving the way for the subsequent explosion in interest in this novel form of relief; Mark having also appeared for Arrow in the original case. See also the related decisions: [2017] EWCA Civ 1, [2017] RPC 9; [2016] EWHC 3383, [2017] RPC 8; [2016] EWHC 2204, [2017] RPC 7.
    • Unwired Planet International Ltd v Huawei Technologies Co Ltd [2017] EWCA Civ 266:  the first of the Unwired Planet cases to come to appeal, and was the subject of intense attention from the industry. Having succeeded at first instance, Unwired Planet successfully defended the judgment on appeal, paving the way for the much discussed FRAND action.

    Jurisdiction & Remedies

    • Vestel Elektronik v Access Advance LLC [2020] EWCA Civ 440, [2021] 4 W.L.R. 60 [2021] F.S.R. 28: this jurisdictional appeal involved a novel attempt by an implementer of the HEVC/H.265 standard to bring a claim for a FRAND declaration against the administrator of a patent pool and a patentee therewithin.
    • Chugai Pharmaceutical Co Ltd v UCB Pharma SA [2017] EWHC 1216 (Pat): this was an application to strike out a claim for want of subject matter jurisdiction which concerned the limits of the power of the Court to consider matters said to engage the validity of foreign patent rights.
    • Fujifilm Kyowa Kirin Biologics Co Ltd v Abbvie Biotechnology [2017] EWCA Civ 1: This was an appeal from the first instance decisions of Henry Carr J (on subject matter jurisdiction) and Arnold J (on personal jurisdiction) in litigation concerning the availability and scope of ‘Arrow declarations’ relating to the world’s largest pharmaceutical product, Humira.
  • Education & awards
    • BA in Natural Sciences (Zoology) 1st class, Clare College, Cambridge 1997
  • Professional memberships
    • Chancery Bar Association
    • Intellectual Property Bar Association
  • Hobbies & interests

    In an earlier life Mark was a keen sportsman, fencing at a national level, coming 2nd as an U20 epeeist, and once squeaking into the top 8 in the national championships. He was also a committed modern pentathlete, obtaining his Blue at Cambridge. Now, however, his exercise is mostly limited to carrying boxes of papers, an occasional run home from chambers and kicking a ball around with his three much loved children. He also remains involved in modern pentathlon, through a charity set up by Mark and two of his team mates (now with 200 supporters) to raise funds for, and generally assist with, the Cambridge University club. As a biologist by training, Mark has had a lifelong interest in wildlife and the environment, and also loves travel, good food and music (mostly of the type with irritating repetitive beeps).

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