Book review: Terrell on the Law of Patents

This is a review of the twentieth edition of Terrell on the Law of Patents, which was released at the end of June 2024. This tome was first published in 1884 by Thomas Terrell, and in the 140 years since, has become a well-established authority for patent practitioners and judges, providing thorough commentary on both the substance and practice of UK patent law. These days, the volume is edited by a skilled team of members of the British intellectual property bar, with Douglas Campbell KC taking over as general editor, and Tim Austen as deputy editor, of the latest edition.

Since the last edition in 2020, there have been significant developments in UK intellectual property law, although the effects of Brexit have been somewhat limited in the realm of patent law. Of course, much has occurred since the establishment of the Unified Patent Court, to which the eighteenth edition of Terrell had optimistically included an entire chapter. However, with the UK's withdrawal from the UPC in 2020, this developing area of patent practice is no longer suitable for a UK-focused text and is not mentioned in the twentieth edition.

Outline of the Contents

There's no need to feel blue:
the new edition of Terrell is here!

The volume generally follows the same structure as previous editions, providing a general introduction to patents (Chapter 1), outlining the nature of patentable inventions (Chapter 2), and discussing the application process (Chapter 3). We then turn to entitlement in Chapter 4, which addresses the Court of Appeal and Supreme Court’s judgments in Thaler v Comptroller-General of Patents, finding that the Patents Act 1977 does not allow for a patent to be granted where the “inventor” is not a natural person, and therefore excludes AI machines. 

Chapter 5 explores the life of a granted patent, including the procedure for opposition and the law on employee inventions. Chapter 6 then considers supplementary protection certificates (SPCs), which are available for medicinal products and plant protection products (i.e. pesticides). It is here that the effect of Brexit is most noticeable. The EU has been considering reform proposals that were published in April 2023, which may lead to a divergence between the EU and UK schemes in the future. The authors also point out that the separate underlying marketing authorisations for Northern Ireland could now lead to differing application of paediatric extensions and, therefore, uneven protection for paediatric medicinal products across the UK. 

Chapter 7 examines the determination of the priority date of an invention. Chapter 8 explains the concepts of the person skilled in the art and common general knowledge. Chapter 9 discusses the construction of the specification and claims. Chapter 10 provides a bird's eye view of invalidity and the grounds of revocation, before we move into the detail of the various grounds in subsequent chapters. Chapter 11 addresses invalidity due to lack of novelty (i.e. anticipation), Chapter 12 focuses on invalidity due to lack of inventive step (i.e. obviousness), then Chapter 13 considers invalidity due to insufficiency.

This Kat was pleased to see that the topic of plausibility now receives separate attention in Chapter 14. Readers of this blog would be keenly aware that plausibility – despite not explicitly appearing in the text of the Patents Act nor the EPC – has been an important development over the last twenty years, which touches on several areas of UK and European patent law, including industrial application, insufficiency, novelty and inventive step.

Another welcome change to the structure of the text is that the chapter on infringement (Chapter 15) has been split up. The defences to infringement (both statutory exceptions and the non-statutory defences) are now considered separately in Chapter 16. The latter chapter includes discussion of the most recent judgments on the (still unresolved) question of whether the so-called Formstein defence exists in the UK. We then turn to the amendment of specifications in Chapter 17, followed by discussion of devolution, assignments, licences, co-ownership, and registration in Chapter 18.

Although the topic received much academic attention during the pandemic, compulsory licences (Chapter 19) did not see any major legal developments in recent years. The chapter simply maintains its detailed description of the law and practice of obtaining a compulsory licence under UK and retained EU law, as well as licences of right. Chapter 20 focuses on the ever-developing law on fair, reasonable and non-discriminatory (FRAND) licences. The chapter contains updates on the most recent case law, including the Supreme Court judgment in Unwired Planet v Huawei, as well as Interdigital v Lenovo and Optis v Apple. 

Chapter 21 explains the general practice and procedure of patent litigation, including case management conferences. The Intellectual Property Enterprise Court and the Short Trial Scheme continue to be dealt with separately in Chapter 22. The remedies for infringement are addressed in Chapter 23, declarations in Chapter 24, and action to restrain threats in Chapter 25. The text concludes with Chapter 26 on use by the Crown. The volume includes three appendices: the full text of the Patents Act 177, extracts of the European Patent Convention, and extracts of the Community Patent Convention (the text of Regulation (EC) 469/2009, concerning the SPC for medicinal products, which was included in the previous edition, has been removed).

Comments

The strength of Terrell lies with its insights into patent procedure and its description of what the law currently is, often accompanied by substantial quotes from relevant judgments. It differs in content and purpose from academic texts that have more space for critically discussing the law, how it has developed, and how it should develop in the future.  

Consider, for example, the increasing number of patent applications that have been subject to restrictions on publication since 2022, likely due to the rise in defence spending since Russia's invasion of Ukraine. Since the fifteenth edition of Terrell, Chapter 3 has explained that UK law provides two grounds for making a direction to keep a patent secret: the information in the patent specification "might be prejudicial to national security," or "prejudicial to the safety of the public." A practitioner who is familiar with the patent legislation in other jurisdictions might be left wondering why the UK has a bifurcated assessment, when other countries do not. 

No edition of Terrell has ever explained that the language of "prejudicial to the safety of the public" was introduced following a controversy whipped up by The Times in 1975, expressing outrage that the declassification of a patent for a chemical warfare agent (known as VX gas) might have disastrous consequences if the specification fell into the hands of terrorists. The image of a would-be terrorist consulting the British patent register for inspiration might seem a little bizarre, but the legacy of this furore is that when the Patents Act 1977 was drafted, the secrecy provisions were expanded. 

We might wonder if the UK Government's embarrassment in 1975 about a nerve gas patent (which had been simultaneously published in the US, Canada, Australia, France and the Netherlands), offers sufficient justification for maintaining an additional ground for withholding patents from publication today. But as a practitioner-focused text, it is arguably to Terrell's credit that the volume does not get distracted by such curiosities that might be prejudicial to the safety of a Kat.

Details

Publisher: Sweet & Maxwell

Extent: 1219

Format: Hardback and eBook (through Thomson Reuters ProView™)

ISBN: 9780414119284