UK – Guide to Preliminary Injunctions in Patent Litigation

Introduction

England is one of the pre‑eminent jurisdictions for patent litigation in Europe, thanks to its relatively fast and well-reasoned decisions, its experienced specialist judges and the robust use of expert evidence.

A Preliminary Injunction (PI) can be a critical tool in UK patent litigation. Whilst they are rarely granted in patent disputes in most technical fields, the UK courts have generally shown a willingness to grant PIs in pharmaceutical cases where market entry can cause immediate, irreversible price erosion. That said, despite an established body of case law granting PIs in pharmaceutical innovator/generic disputes, in recent years the English courts have become more unpredictable and what used to be a relatively easy remedy to obtain in certain circumstances is now being subjected to greater judicial scrutiny.

The law governing the grant of PIs in the UK focuses more on economic factors and the balance of justice than on the merits of the case. In generic and biosimilar disputes, a defendant is expected to “clear the way” by seeking revocation of the patent and/or a declaration of non-infringement prior to launch. If it does not do so, this may be a strong or even decisive factor in favour of the grant of a PI.

The most prominent reason that applications fail in the UK for a PI in technical fields outside pharmaceuticals is because damages are usually an adequate remedy to compensate the patentee for their losses. That said, where the patentee does not license its patents and where there will be permanent market damage if the alleged infringer launches its product or remains on the market (if launch has taken place), then a PI may be granted by the UK courts. The same legal test applies when deciding that PI application as in pharmaceutical cases, set out below.

It is also possible to obtain an anti-suit injunction (ASI) from the UK courts where there is an imminent threat in overseas proceedings of a patentee obtaining a PI affecting the UK market in circumstances where the parallel interim relief would be refused in the UK.

Another remedy which has become prominent in recent years is an anti-anti-suit injunction (AASI) typically granted by the UK courts where:

• one party has asked the UK court to determine Fair, Reasonable and Non-Discriminatory (FRAND) licensing terms for standards essential patents (SEPs); and
• there are parallel proceedings overseas where the foreign court is likely to grant an ASI which would prevent all or part of the UK FRAND case proceeding.

This situation crops up most commonly where technology implementers ask the UK courts for a declaration of entitlement to a global interim license. The intention of technology implementer litigants is to persuade SEP owners to enter into an interim license, where the implementer pays global royalties to be set by the UK court covering the past and present during the litigation (which may be adjusted at the final FRAND determination), and thereby avoid PIs and final injunctions in overseas jurisdictions that would prevent them operating. This UK declaration jurisdiction has resulted in the UPC and German national courts ordering anti-interim license injunctions (AILI) – a specific type of ASI - to preserve the UPC’s and German court’s ability to award injunctions impacting their territory. The UK AASI jurisdiction has been invoked in response, to encourage willing licensor behaviour from SEP owners. This case law is developing rapidly and is highly controversial.

Triggers for seeking a preliminary injunction in patent / SPC matters

There is no fixed deadline for applying for a PI, and there is no need to wait for the defendant to make infringing offers in order to obtain a PI. What is important is that the defendant may launch sometime within the lifetime of the patent, i.e. there must be the existence of a threat and intention to start selling the product before patent expiry (Teva v Chiesi ([2020] EWHC 1311 (Pat)).

A PI can therefore be applied for on a quia timet basis where a defendant is threatening and intending to commit an infringing act. The following may be relevant:-

1. Grant of a Marketing Authorisation (MA)

The act of obtaining an MA alone may be sufficient basis for applying for a PI on a quia timet basis, particularly if:-

• The MA has been obtained well in advance of patent expiry.

• The defendant refuses to disclose its marketing plans and refuses to commit to waiting for patent expiry or the conclusion of any proceedings to clear the way. This can create a strong inference of an intention to launch before expiry.

• The defendant has not taken any steps to “clear the way”.

• The defendant has previously launched pharmaceutical products “at risk”.

2. Application for revocation and/or a declaration of non-infringement

The fact that a company has taken steps to clear the way (for example, by starting revocation proceedings), even if it has not obtained an MA, may be sufficient to support an application for a PI. Again, the defendant’s actions, such as a refusal to give information about launch plans, may be an important factor.

 

Timing

It is always necessary for a party to act quickly when seeking a preliminary injunction. The equitable doctrine of laches applies to an application for a PI such that injunctive relief could be refused on the basis that there has been unreasonable delay that has prejudiced the other party. 

Even if the court considers that the delay is not such as to disentitle the patentee to relief on the basis of laches, the delay may affect the consideration of status quo leading to refusal of the PI if the defendant is already on the market.

The test as set out in the leading Case – American Cyanamid v Ethicon

In considering whether to grant a PI, the UK courts have traditionally applied a 4-stage test (American Cyanamid Co v Ethicon Ltd [1975], as more recently summarised by the Court of Appeal in Neurim Pharmaceuticals v Generics (UK) [2020] EWCA Civ 793).

In applying the American Cyanamid test, the court will consider the following questions.

Question 1: Is there a serious issue to be tried?

• This is a very low merits threshold – it is not a mini-trial.
• Infringement must be arguable – it does not have to be “more likely than not”.
• The patent must not be plainly invalid.
• The court should not attempt to resolve critical disputed questions of fact or difficult points of law.

Questions 2 and 3: Adequacy of damages - Would damages be an adequate remedy for the patentee for the loss sustained pending trial as a result of the defendant’s acts? If not, would damages (on a cross-undertaking) be an adequate remedy for the defendant if the defendant were to succeed at trial?

• In general, the more uncertain the quantification of damages, the more likely it is that damages would not be deemed to be adequate. This is highly fact sensitive.
• The court will consider:-
  1. If the injunction is not granted, would damages be an adequate remedy for the patentee?
     • In pharmaceutical cases, it is well recognised that there are very different market dynamics compared with patents in other fields.
     • This class of cases is distinguished by the following factors in particular:
     • Entry of one generic often leads to multiple generic entry, which is liable to lead to price-cutting and a resultant downward price spiral.
     • The practical ability of a patentee to restore its previous price if later successful at trial is generally constrained due to the way pharmaceutical pricing works in the UK.
2. If an injunction is granted, would damages be an adequate remedy for the alleged infringer?
   • Here the court will particularly have regard to arguments about any “first mover advantage” – if the defendant is likely to be the only generic on the market, it might be able to achieve a near monopoly price in the absence of competition.
   • The defendant will also usually have no track record of selling the product, making it difficult to quantify lost sales.

Question 4: Where there is doubt as to whether damages would be an adequate remedy for either side or both, where does the balance of convenience (or the risk of injustice) lie? 

The Court hearing an application for a PI is often required to make its decision on the basis of limited information in a rapidly changing situation. That can mean that it is difficult to determine the adequacy of damages for either side. If so, the court should take into account all other relevant factors that are put before it and consider the balance of convenience (or risk of injustice). This can include significant weight being attached to the impact on third parties, such as the National Health Service (NHS), where the court may have regard to factors such as pricing impact and procurement dynamics.

In answering Question 4, the court will therefore seek to determine what is the least harmful option – the basic principle is that the court should take whichever course seems likely to cause the least irremediable prejudice to one party or the other. The court should also take into account whether the defendant could have cleared the way. Where the other factors appear to be evenly balanced, the court is likely to preserve the status quo.

 

Willingness of the UK Courts to grant a PI in pharmaceutical cases

In general, a well established line of cases has shown that the UK courts are often willing to grant PIs in pharmaceutical cases. Given the UK court’s willingness to grant PIs, generic companies have been known to agree to stay off the market pending a decision on the merits, in return for a cross-undertaking in damages. This enables them to avoid liability for the costs of the application for a PI, and to claim damages for the period when they could have launched but didn’t, if they are successful in relation to non-infringement and/or revocation due course.

However, despite a substantial body of case law over the past 25 years where PIs have been granted, in recent years there have been cases where generic companies have successfully defended an application for a PI.

For example, in Neurim v Generics (T/A Mylan) [2020] EWHC 1362, a PI was refused on the basis of what were considered to be unusual circumstances, including that:

• There was a short period of assumed infringement because the trial had been expedited and would be heard in four months’ time.
• More than half of prescriptions in the UK were written by brand rather than generically. In the UK, those prescriptions can only be satisfied with the branded product even when the generic product becomes available. This provides some protection against generic competition.
• There was no evidence that any other generic would come onto the market before trial and therefore a downward price spiral was unlikely.

The court also considered that Neurim could be adequately compensated in damages because there was sufficient past sales price data to be able to quantify price depression from the competition, and there were comprehensive sales forecasts to assist in quantifying loss.

The High Court also recently refused an injunction in AstraZeneca v Glenmark [2025] EWHC 748 (Pat), which is discussed further below. Although this decision was reversed on appeal (largely due to a change in circumstances between the two decisions), it illustrates how greater scrutiny is now being applied by the court in balancing all of the factors relevant to the application for injunctive relief. There has been something of a shift from broad assumptions to economic analysis, with a higher onus on the patentee to prove irreversible harm.

 

The application and decision

An application for a PI is usually made inter partes (an ex parte application would only be appropriate in unusual circumstances). It is supported by evidence which relates wholly (or primarily) to the commercial factors relevant to the PI – economic expert evidence may be allowed. There usually will be no technical expert evidence.

A decision would usually be given by the court, at the latest, within a few weeks of the hearing of the PI application.

 

Is a bond or cross-undertaking payable when filing a preliminary injunction application?

If a PI is granted, the patentee must give the court a cross-undertaking to pay damages to the defendant if it is later determined on the merits that there is no infringement or the patent is invalid. A bank guarantee is not usually required.

Damages may also be payable to any third party who is affected and joined to the Order – for example, in the case of a human medicinal product, this might include the NHS.

 

Right to appeal

PI decisions may be appealed to the Court of Appeal. The Court of Appeal has shown a willingness to hear appeals within a very short time frame (days or weeks). In some cases, injunctive relief might be available pending appeal (this is discussed further below).

 

Blocking injunctions

Beyond traditional PIs, the UK courts have also demonstrated a willingness to deploy other forms of injunctive relief to protect pharmaceutical rights holders.

In Novo Nordisk A/S v British Telecommunications plc & ors [2026] EWHC 1094 (Ch), the High Court granted a website blocking injunction in the UK in relation to the supply of counterfeit and unlicensed prescription-only medicinal products. After being asked for support by the Medicines and Healthcare products Regulatory Agency (MHRA), Novo Nordisk sought and obtained an order directed at four target websites.

A few months later, the blocking order was not only expanded to cover a further seven target websites, but also to allow “dynamic blocking” (Novo Nordisk A/S v British Telecommunications plc & ors [2026] EWHC 1535 (Ch)). Dynamic blocking removes the need to repeatedly seek blocking orders from the court by enabling self-certification of infringement on the basis of a number of designated (confidential) criteria. The patentee can then notify internet service providers (ISPs) directly, and require the ISPs to take steps to block the offending websites.

In granting the blocking injunction, the judge acknowledged that the law is not afraid of adapting to new and fast-moving challenges – in his opinion, the context strongly suggested the need for a form of creative intervention. Not only were private rights being infringed, with wrongdoing both widespread and varied, but a clear public health issue seemed to weigh heavily on the decision.

 

Recent Decisions / Developments

Application of the American Cyanamid test

Recent case law has shown that the way the English courts apply the American Cyanamid test is becoming more nuanced, with some shifts in emphasis. The Court of Appeal recently commented that the courts will often be in doubt as to the adequacy of the respective remedies in damages, making the assessment of the balance of convenience (or risk of injustice) an important and decisive factor in many cases. As discussed below, the balance of justice test seems to be being applied in a more holistic way than previously, with greater scrutiny of the commercial factors and a higher evidential burden. And whilst third-party harm has always been a relevant factor, recent cases have shown that the courts are willing to carry out a sophisticated analysis of the NHS’s position.

Despite this shift, the UK courts currently remain bound by the American Cyanamid test, and the Court of Appeal recently confirmed that it could not follow the more flexible approach that has been adopted by the Irish courts (MSD v Clonmel). There is presently a live question as to whether the American Cyanamid questions are to be applied in a rigid and strictly sequential manner (essentially considering each question in isolation from the others and in order: serious issue; adequacy of damages; balance of convenience; status quo), or whether a more holistic approach should be adopted¹. Further guidance is eagerly awaited.

Greater judicial scrutiny of the commercial factors

Historically, in disputes between innovators and generics, the English courts fairly readily accepted that price erosion would take place and would be inherently irreversible, and this weighed in favour of the grant of a PI. In recent cases, the courts have interrogated the adequacy of damages with much greater rigour. Judges have required granular proof, not merely broad assertions, about the potential long-term price effects, noting that whether a price spiral will occur is intensely fact specific.

In AstraZeneca v Glenmark [2025] EWHC 748 (Pat), the High Court refused to grant an interim injunction on the basis that damages would be an adequate remedy for AstraZeneca because they could be calculated with a reasonably high degree of accuracy, and that damages on the cross-undertaking would not be an adequate remedy for Glenmark nor for the NHS. Factors considered included that there was no evidence that AstraZeneca would be likely to change its price and no evidence that, even if it did, it would not be able to reverse that in due course. There was also uncertainty as to the extent to which the defendant would have benefitted from being the first generic entrant. Ultimately, the court found that the quantification of damages due to Glenmark would be significantly more difficult than assessment of the damages due to AstraZeneca. Although the status quo would favour the grant of an injunction had other factors been evenly balanced, the judge said that, in his judgment, they were nowhere near being evenly balanced.

The Court of Appeal subsequently reversed this decision. However, by the time of the appeal of the PI application, there was evidence that other generics were preparing to enter the market and that this was likely to happen more quickly than the judge at first instance had anticipated, and this new evidence therefore undermined the assessment of the judge at first instance. On the basis of the new evidence, the Court of Appeal held that it was inevitable that there would quickly be price competition between three or more generic entrants leading to a downward price spiral.

Ultimately, the Court of Appeal found that there was (by that time) real doubt as to the adequacy of damages for both parties (and for the NHS) and as it was not possible to form a reliable view as to which side was more at risk of receiving an inadequate remedy in damages, given the shortness of the period in question, the status quo should be preserved. The Court of Appeal also found that the judge at first instance was wrong to discount Glenmark’s failure to clear the way when considering whether to preserve the status quo – a party must take all steps necessary to obtain a judgment before launch – and wrong to discount the fact that Glenmark sought to launch its product in the middle of trial. Launching 'at risk' would inevitably make it more difficult for the court to do justice to all the parties in due course. 

Lesser importance of the merits

Whilst other courts (including the Unified Patent Court) consider validity of the patent to be an important factor in the decision as to whether to grant injunctive relief, as mentioned above the UK courts do not attach such significance. This was highlighted in Bayer v Sandoz & Ors [2024] where the High Court extended a preliminary injunction (initially granted for a brief period after expiry of the SPC until judgment) pending appeal, despite the fact that Bayer’s patent had been found invalid. In granting the injunction, the High Court emphasised that the injunction only related to a short period and that, in short cases such as this, maintaining the status quo of the market is particularly important.

Status quo

The type of injunctive relief seen in Bayer v Sandoz, which aims to “hold the ring” for a relatively short time by maintaining the status quo, has been seen recently in a number of cases. Indeed, there is something of a trend at the moment for making a series of applications for a short PI at various stages in the proceedings. This enables the court to react to changing market conditions and to weigh up which party faces the greatest risk of injustice on the basis of the current risks of market disruption.

In AstraZeneca v Glenmark [2025], after granting a PI until conclusion of the Form of Order hearing (a hearing that takes place following judgment), the Court of Appeal contemplated that AstraZeneca might seek further injunctive relief and commented, “[f]or the avoidance of doubt, this does not dictate the outcome of any application that might be made by AstraZeneca for a further injunction at [the Form of Order hearing]. Any such application will need to be considered on its merits in the light of the relevant circumstances at that stage”. AstraZeneca did then seek an interim injunction pending appeal, which was granted. A factor in that decision was that the Court of Appeal was expected to deliver its decision within four weeks.

The importance of preserving the status quo was also evident from the decision in Bayer v Aspire [2024] EWHC 711 (Pat) where an injunction was granted to cover the period between trial and judgment. The judge highlighted that the short and crucial point about the application was that it was designed to preserve the status quo for a period of 9-10 days and doubted that either party would suffer a great deal of irreparable harm in that time. In contrast, to refuse an injunction would have changed the status quo in respect of an application after judgment, which had the potential to give rise to significant irreparable harm to the patentee.

These cases have demonstrated the importance of preserving the status quo between first instance and appeal, particularly in circumstances where the gap between first instance and appeal proceedings is likely to be short.

Behaviour of the parties

The English courts have been quite clear that they expect the parties to put orderly resolution of the dispute ahead of trying to obtain commercial advantage. The Court of Appeal in AstraZeneca v Glenmark summed up the expectation of the courts, as follows:

“As judges both in the Patents Court and in this Court have observed in a number of cases, it is important that parties should behave in a manner which is conducive to an orderly resolution of disputes of this kind, and not attempt to gain a commercial advantage by disrupting such orderly resolution. The effect of Glenmark’s conduct in this case has been to require a day of argument in the Patents Court and a day of argument in this Court to be devoted to, and very considerable costs to be expended on, the question of what is to happen during a period of one to three months. That is not a good use of the parties’ resources, still less a good use of scarce court resources.”

PI application on a patent application

In Novartis v Teva & others [2022] EWHC 959, Novartis sought a PI to prevent generic launch of the multiple sclerosis drug fingolimod (which Novartis sells under the brand name “Gilenya”), relying on a patent application which was still pending grant at the EPO. The Court held that the fact that the patent had not yet been granted did not present a bar to interim relief, making it clear that a PI can be sought on the basis of a patent that has not yet been granted.

However, the patent application in question was a second divisional from a much older parent application and the court commented that the practice of making repeated divisional filings and amendments so as to prevent generics from effectively seeking to clear the way is a factor that weighs against the granting of interim relief.

The facts in this case were unusual, because fingolimod is supplied only in secondary care such that its price is not determined by the NHS drug tariff, so the Court considered that generic launch was unlikely to cause an irrecoverable downward price spiral. The Court therefore held that damages would be an adequate remedy for Novartis if the patent were ultimately held to be valid and infringed, and refused the PI.

Willingness of the UK Courts to grant an ASI

The availability of an ASI is particularly relevant to cases where the patentee is seeking the UPC’s relief under its “long-arm” jurisdiction and also in patent infringement actions before national European courts where, in either situation, infringement of the UK portion of a granted European Patent is alleged and the patentee seeks to benefit from a cross border PI and/or final injunction pursuant to the CJEU’s jurisprudence in BSH Hausgeräte GmbH v Electrolux AB CJEU case C-339/22. The alleged infringer has the opportunity to initiate UK proceedings seeking a declaration of non-infringement and/or seeking revocation of the UK portion of the European Patent. In those proceedings, it is possible to seek an ASI to prevent the UPC or relevant European national court from determining the UK aspects of the proceedings before the foreign court.

In Cook UK Ltd v Boston Scientific Ltd [2022] EWHC 504 (Pat), a request for such an ASI was made in response to “kort geding” proceedings in the Netherlands by Boston Scientific against companies, including the applicant, alleging infringement of the UK, French and Irish designations of their European Patent for a surgical clip for treating gastrointestinal bleeding. While an ASI was not granted pending a full hearing on the issue, Mr Justice Meade did order that the respondents had to give the applicant at least 72 hours’ notice of any application to any court in the Netherlands to restrain or interfere with the intended UK action relating to the patent’s validity or infringement, or with the applicant’s intended ASI. The ASI issue was ultimately disposed of by consent in that case; Cook withdrew its claims in the Netherlands regarding the alleged UK infringement. 

The principles to be applied when deciding an ASI application were set out in Deutsche Bank v Highland Crusader Offshore Partners [2009] EWCA Civ 725. Specifically:

• The party seeking an ASI must generally show that proceeding before the foreign court is or would be vexatious or oppressive.
• In order to establish this on grounds of forum non conveniens, it is generally necessary to show that:
  • England is clearly the more appropriate forum, and
  • justice requires that the patentee in the foreign court should be restrained from proceeding there.
• Even if those points are established, the important restraining influence of considerations of comity are relevant.
• The principle of comity requires the court to recognise that, in deciding questions of weight to be attached to different factors, different judges operating under different legal systems with different legal polices may legitimately arrive at different answers, without occasioning a breach of customary international law or manifest injustice, and that in such circumstances it is not for an English court to give to itself the decision how a foreign court should determine the matter. The stronger the connection of the foreign court with the parties and the subject matter of the dispute, the stronger the argument against intervention.
• The decision whether or not to grant an ASI involves an exercise of discretion and the principles governing it contain an element of flexibility.

Willingness of the UK Courts to grant an AASI

In Warner Bros. Discovery v Nokia [2025] EWHC 2888 (Pat), an AASI was awarded to the applicant to avoid the possibility of an ASI or AILI being granted by the UPC or German national courts, even though Mr Justice Mellor was sceptical about whether there was a real risk that the respondent and SEP owner, Nokia, would seek that potential relief. In that case, a non-negligible risk was enough. The AASI was awarded without notice to Nokia.

Critical factors to the decision were:

• Whether Nokia had sought ASI relief in the past, particularly regarding recent and pending RAND determinations in the UK courts (Nokia had not).
• Whether Nokia had a track record of pursuing injunctive relief despite technology implementers commencing RAND actions before the UK courts, which was consistent with a strategy of using commercial pressure on implementers to accept licensing offers at royalty rates which were higher than they should be (Nokia had this track record).
• Whether Nokia had sought and obtained AASIs without notice before the German national courts and the UPC (Nokia had, against Continental and Sunmi respectively).
• Whether Nokia might copy others (specifically, InterDigital) who had obtained AILI relief from the UPC and German national courts. However, it was noted that Nokia had not, at that point, sought any overseas ASI or AILI relief against Acer/ASUS/Hisense who were also pursuing UK RAND determination proceedings against Nokia.
• Whether Nokia had sought to prevent RAND claims brought by implementers being heard in the UK through jurisdiction challenges, case management stay applications and a general strategy of putting commercial pressure on implementers by litigating in multiple jurisdictions (Nokia had).
• Whether this was the UK court’s only chance to protect its jurisdiction against the AILI risk (it was).
• Whether a short period until a substantive hearing with both parties would prejudice Nokia unduly (it would not; if Nokia did or did not want to seek AILIs this short delay would not create practical difficulties for Nokia in pursuing its chosen litigation tactics).

However, in Paramount v Nokia [2025] EWHC 3083 (Pat), decided just 3 weeks later and which had a very similar fact pattern to the WBD case, an AASI application was not successful. The application was made by Paramount on a without notice basis, in the same way as the WBD case. The respondent and SEP owner, Nokia, had however given evidence in the WBD case after grant of the AASI in preparation for the return hearing to decide whether the AASI should be maintained. This evidence stated that Nokia had not applied for an injunction in any jurisdiction seeking to prevent WBD from bringing a claim anywhere in the world and that Nokia did not intend to apply for an injunction to prevent WBD prosecuting any aspect of that claim in the UK.

Mr Justice Meade decided to exercise his power under the English court rules to use a witness statement for purposes other than the action in which it is provided. He disclosed a short extract of that evidence on a strictly confidential basis to Paramount and its legal team. Paramount then accepted that its AASI application had been overtaken by events. Paramount reduced the relief it sought to simply require Nokia to make statements about its actions and its intentions in Paramount’s RAND litigation, presumably in the expectation that Nokia would commit to not seek an AILI against Paramount. If so, an AASI would not be needed. That said, the Judge confirmed that Paramount had the option to renew their AASI application if needed at any time.

Subsequently, another dispute in this area has further highlighted the jurisdictional conflict between the UK High Court and the UPC concerning the effect of the UPC’s ASI on UK RAND proceedings.

Separately, interim licence declarations have become an established remedy in the UK in SEP/FRAND disputes, providing a mechanism for implementers to avoid the risk of PIs and final injunctions in overseas jurisdictions pending a final FRAND determination by a UK court. While this developing area of case law is beyond the scope of this Guide, it is significant and has led to increasing jurisdictional tension between the UK courts and the UPC.

 

Takeaways

Whilst the American Cyanamid test remains intact, its application is adapting to address complexities in pharmaceutical patent litigation. The adequacy of damages limb of American Cyanamid is now applied with a more rigorous and evidence-heavy approach, which has led to deviation from what used to be a near-automatic assumption of irreparable harm for innovators. This, in part, reflects the fact that economic consequences of launching or not launching are significant for the parties. Evidence relating the adequacy of damages is also critical to PI applications for products and processes other than pharmaceuticals.

Key takeaways in relation to PIs in the UK are as follows:

• Defendants should generally clear the way.

• Patentees should act promptly.

• The behaviour of the parties is relevant, including launch strategies, regulatory steps and communication.

• The patentee should prepare detailed evidence on market conditions, price erosion and recovery.

• There is detailed consideration of the potential harm to third parties (such as the NHS).

• There is greater weighting of the balance of convenience/risk of injustice test where there is uncertainty as to the adequacy of damages.

• Maintaining the status quo may be an important factor.

• The Court of Appeal is willing to reverse decisions at first instance, particularly where the commercial landscape has changed.

ASIs and AASIs are available to alleged infringers where there are parallel proceedings overseas that have been asked to determine UK patent infringement and/or validity. AASIs are also available in SEP cases where a FRAND determination has been requested by any party and the SEP owner may attempt in parallel overseas infringement proceedings to limit the scope of the UK proceedings. 

For further details about patent law in the UK, see our Patent Litigation Comparator Guide.