If Hollywood made patent cases: how a German town became the centre of a landmark patent dispute

SH Patent Attorney

9 hours ago

33 min read

The town of Dieburg is situated on the northern fringe of the Odenwald, an undulating forestry region south of Frankfurt am Main — Germany’s capital of finance. Dieburg (pronounced Dee-boorg), like Frankfurt, is in the state of Hesse in central Germany and has an attractive cobbled marketplace and traditional, period houses. The locals would say it stands out due to its Roman history and community enthusiasm for the annual Carnival celebrations, but compared to neighbouring town and city centres in the Rhine-Main area, Dieburg isn’t particularly remarkable. Few would have expected little Dieburg be able to deliver of one of the most interesting procedural disputes to emerge from the Unified Patent Court (UPC) to-date.

Indeed, the long-running dispute involving Dieburg’s MedTech manufacturer Polytech Health & Aesthetics has produced a rollercoaster journey of decisions that every patent practitioner should read. The case’s most interesting element concerns something that is becoming increasingly important in European patent litigation: control over the where. But before we get stuck in, let’s set the scene and consider the basic facts. So, hold on tight, the rollercoaster is leaving the station...

The Rio connection

The dispute centres on European patent EP2581193 relating to a process for manufacturing silicone (breast) implants. EP’1193 was filed in 2011 in the name of Polytech as a European direct case without priority claim and the grant proceedings were handled by the German firm Boehmert & Boehmert (referred to herein as “B&B”), who prosecuted the application to grant without much difficulty. It seems that manufacturing such implants well is no trivial matter — multiple layers need to be bonded to each other, quickly, accurately and efficiently, without any gaps, folds, wrinkles or air pockets, nor risk of delamination or implant shape deformation over time. Since these implants are for use in not only breasts, but also thighs, buttocks and calves, and may be implanted not only for aesthetic reasons, but potentially during reconstructive surgery following a traumatic injury or amputation, can you imagine the patient discomfort and upset that could follow from an implant degrading, leaking or deforming over time, necessitating invasive surgery to be corrected?

EP patent ’1193 granted in 2015 and divisional application EP3002101 was filed shortly beforehand. The parent EP’1193 was validated and paid up in circa 20 countries and wasn’t centrally opposed before the EPO. In November 2021, the divisional EP’2101 was about to grant, when something strange happened — the applicant failed to pay the grant fee in due time and before the 2-month further processing period (revival deadline) had expired, an unusual letter from Östersund in Sweden appeared in the EP Register. It was sent to the Legal Division of the EPO for its urgent and immediate attention.

So, what was the emergency? In her letter of 12th November 2021, Anna Ingebrand of patent law firm AWA Sweden AB explains that her client, a Brazilian company called Silimed based in Rio had instituted ownership entitlement proceedings against Polytech in Germany and therefore stay of the examination proceedings was requested. It seems that there was a dispute going on behind the scenes on who was the actual rightful owner of the silicone implant process and the patents that had been filed on it.

No immediate response by the EPO to Silimed’s request for a stay could be found in the register, but a couple of weeks later, further processing was duly requested by B&B on behalf of Polytech, putting the divisional application EP’2101 in order for grant. It is not clear why Dieburg’s Polytech (B&B) failed to handle the grant formalities in time nor exactly why Rio-based Silimed wanted grant proceedings to be put on ice, and indeed why this seemed to induce Polytech to suddenly want grant of ‘their’ divisional after all. Had Polytech thought abandonment of the divisional actually be a better tactical option, but then changed their minds? One can only imagine the discussions that doubtless happened behind closed doors in Germany, Brazil and Sweden!

However, a few days later, the Legal Division of the EPO ruled that proceedings for the divisional could not be stayed since the entitlement proceedings related to the parent case EP’1193, for which EPO grant proceedings had closed in 2016 — the divisional was to be treated as a separate and independent patent application. A few weeks afterwards, the request for further processing was allowed and in March 2022, the EPO emitted the decision to grant the divisional EP’2101.

From Frankfurt to Karlsruhe and back

So, what had been happening in the German national courts in relation to the patent ownership such that it began to spill out into the EP register?

In 2017, the Brazilian company Silimed filed an ownership entitlement action (Vindikationsklage) before the regional court (Landgericht or LG) in Frankfurt in relation to the granted parent EP’1193. Whilst close by, Dieburg is not actually in the district that the Landgericht Frankfurt covers for its main matters, but the court is actually additionally responsible for all patent disputes in the entire state of Hesse and therefore also Dieburg, where the defendant in the entitlement action was domiciled. According to a number of articles by Juve Patent and Valor International, the Brazilian company Silimed alleged that the invention had actually originated from confidential information shared during the parties’ commercial collaboration — the Dieburg-based Polytech is stated to be Silimed’s distribution partner from the 1990s up until 2008. Silimed’s implant products were made in Brazil and exported to Germany for final packaging and Polytech is said to be responsible for certifying Silimed’s products with the Conformité Européenne (CE) mark mandated for marketing such products in the EU. Silimed claims it disclosed to Polytech the process claimed in EP’1193 under the confidentiality clauses of their agreement, as a necessary part of the CE certification steps. In other words, Silimed was of the opinion that the invention claimed in EP’1193 belonged to them and Polytech was not entitled to EP’1193, the national parts of which Silimed requested be transferred to them and Silimed be awarded damages from Polytech to compensate for Silimed’s losses.

Unfortunately, these were not quick and easy entitlement proceedings! In 2019, the Landgericht Frankfurt dismissed Silimed’s claim because Silimed could not produce sufficient documentary proof that their employees in Brazil had actually first invented the process and it had been assigned to Silimed, either actively or automatically e.g. as a result of an employment contract under Brazilian law. The Landgericht Frankfurt could not reach full judicial conviction (was not completely persuaded) that the facts claimed were true — Silimed had failed to persuade the German court that the invented process belonged to them. Silimed appealed to the Oberlandesgericht (OLG or Higher Regional Court) of Frankfurt, the second instance court a few hundred metres away in downtown Frankfurt. Unfortunately for Silimed, in November 2020, the Oberlandesgericht Frankfurt agreed with the first instance decision in view of the missing evidential record of inventorship in Brazil. So, it seems that Silimed’s missing paper trail was a decisive factor.

Silimed didn’t give up — in 2022 it appealed to the Bundesgerichtshof (the German Federal Court of Justice) in Karlsruhe, a German city further south near the French border, on the point of law relating to evidentiary proof. Indeed, the difficulty of the situation was that Silimed couldn’t produce sufficient documentary proof of entitlement because the documentation wasn’t in its possession — so the proof did in fact exist, it just wasn’t accessible to Silimed. That missing link must have been very frustrating and expensive!

Arbitration tips the balance

Meanwhile Silimed had also been busy in arbitration before the International Chamber of Commerce (ICC). Since arbitration is normally completely confidential, there is limited public information on the case, but what is known is that in October 2022, the ICC Tribunal found that Polytech had unlawfully used Silimed’s trade secrets and confidential know-how arising from their long-standing business relationship. In December 2023, the ICC tribunal awarded damages in Silimed’s favour (the sum is undisclosed). So, after so many setbacks, the Brazilian company finally started to turn things around.

What then happened to the appeal by Silimed to the German Bundesgerichtshof on points of law regarding the patent entitlement proceedings? Well, the Bundesgerichtshof felt that the lower German courts should have compelled the (third?) party in possession of the evidentiary proof of inventorship/assignment to Silimed to produce those documents to the court under paragraph142 ZPO (the German rules on civil litigation procedure). Like many civil law countries, Germany provides no options resembling US discovery. The case was thus remitted back to the Oberlandesgericht Frankfurt, which then proceeded to effect the order for the production of the evidence. Evidentiary proof was submitted and a witness heard and cross-examined, which is unusual in German patent litigation. Finally, the missing link of paperwork was closed and in November 2024 the Oberlandesgericht concluded that Silimed was in fact entitled to EP’1193 in full and Silimed be transferred the patent. Polytech should also provide financial accounts, which is the prerequisite step for an award of damages to Silimed.

The tables were suddenly turned

The November 2024 German Oberlandesgericht Frankfurt ruling on patent entitlement dramatically changed the parties’ positions. The EP’1193 claimed not only the process for making the implants and intermediate products of such process, but also had claims explicitly dedicated to the implants, and implant shells, obtained from the process.

Under §9 of the German Patent Act (PatG), the acts of infringement of such claims include using the patented process and offering the process for use, as well as making, offering, placing on the market, using, and importing the following items:

implants directly made by the process;
intermediate products directly made by the process;
the implants obtained by the process;
implant shells obtained by the process.

The business relationship between Silimed and Polytech is reported to have ended in 2008 and the EP’1193 patent was filed in 2011. So, having considered the invention its own, investing the time and resources (legal fees) to have the invention patented, validated across Europe and further afield — and all those patent filings be annually renewed — Polytech was no longer distributing Silimed’s implants made in Brazil, it was making and selling its own implants. So, the patent claims could be directly relevant. Former patent proprietor Polytech suddenly faced the prospect of becoming an alleged infringer of the very patent it had filed and once owned.

Indeed, on 5th January 2026 Silimed became the new legal owner and in February 2026, Silimed was registered as the new patentee for the German patent of EP’1193.

So, what happened in 2025? Before we discuss that bump in the road, let’s first consider how this dispute may have arisen in the first place.

What about inventor remuneration?

As is often the case in disputes, we will likely never truly know what really happened between the parties back then when the distribution arrangement between Silimed and Polytech is said to have ended (2008) and the EP’1193 patent was filed in few years later (2011). Was it really the case that Silimed’s employees in Brazil had invented the process? Had record of this by the inventors been documented at the time of the invention? Or maybe that documentation had been misplaced or had left Silimed’s control? Perhaps Silimed had taken a relaxed approach and not paid much attention to (potential) intellectual property matters? Did Silimed assume an improvement in their processes would automatically be treated as a company trade secret, even when not documented? Maybe the new implant manufacturing process was actually invented as a result of a collaboration between the parties and both sides felt that they had contributed all of the inventive effort and the other side merely non-inventive support? Was Polytech in fact justified in its apparent belief in its employees having invented the process?

Under a German statute called the ‘employee invention law’, Arbeitnehmererfindungsgesetz (or ArbEG, which is not to be confused with a popular brand of whiskey, no matter what autocorrect may lead you to believe to the contrary!), it is a statutory requirement for an employee to report the details of their invention (or contribution to an invention) to their employer. If the inventors have an employment contract governed by German law, compliance with ArbEG is necessary, irrespective of the nationality or location of the inventors — so certainly inventions created (in part) during a business trip abroad, or sometimes even during an expat assignment, will still count as an ArbEG invention. As soon as possible after receipt of notice detailing an invention (unless the employer actively gives up its interest in the invention or deems it a trade secret) the employer is required to file a patent application and each inventor is entitled to a small cut of the economic value created by the invention and enjoyed by the employer. Inventor remuneration is usually calculated based on any profits achieved by the employer stemming from the patented monopoly internationally. The EP’1193 patent was not only filed in Europe, but also in the USA, Brazil, Russia, South Korea, China, Hong Kong and Australia. So, the total profits from the patented monopoly could have been quite substantial.

If its inventors had already been remunerated by Polytech before the decision on entitlement, this raises some intriguing questions:

If inventor remuneration has already been paid, is there any legal basis to reclaim it?
What about unjust enrichment by the inventors?
What about the standard 3-year limitation period for civil claims under German law?
If remuneration has not yet been finally calculated or paid out, should later events—such as having to transfer the patent or pay infringement damages—be taken into account when determining the invention’s economic value?
Does the later loss of the patent retrospectively reduce the invention’s value?

Looking more closely at the public records, some interesting facts are revealed. EP’1193 as granted names two inventors, both of which having residential addresses in the region surrounding Dieburg. The applicant and patentee for EP’1193 is the German legal entity Polytech Health & Aesthetics GmbH — the GmbH is shorthand for ‘Gesellschaft mit beschränkter Haftung’, which is equivalent to limited liability company (Ltd). However, when originally founded in 2006, the name of this legal entity was actually Polytech-Silimed Europe GmbH and the sole company director (Geschäftsführer) registered at this time is associated with a city called Ilhéus in Brazil, which incidentally is not near Rio. So, was this a kind of joint venture or jointly owned company? Only a few months later, this person was however replaced by a new company director based in Germany. In 2008, the company was then renamed Polytech Health & Aesthetics GmbH. Was it within this 2006 to 2008 time period when Polytech and Silimed effectively concluded that their business goals were not aligned?

On EP’1193 and its divisional EP’2101, one inventor’s name is stated to be Patrick O’Leary. Whilst his address on the patent was originally located in the Dieburg area, his address was later updated to a residence in the USA for the divisional EP’2101. Indeed, prior to the EU data protection regulation (GDPR) coming into force in 2018, it was standard practice to provide the patent offices with an inventor’s personal (residential) address. According to his LinkedIn profile, O’Leary was educated in the USA and was CEO of “Polytech Health & Aesthetics” in Dieburg from 2008 to 2013. For the German inventor remuneration (ArbEG) rules to apply, the law governing an inventor’s employment contract at the time the invention was made must be German law. As previously mentioned, the nationality and location of the inventor is not taken into account, nor does it matter if the employee later leaves or retires from the company. So, O’Leary need not be a German national nor have been located in Germany at the time he made his contribution or even be currently employed to be able to be remunerated for past inventive contributions. However, company directors (Geschäftsführer), including a CEO, are not considered “employees” per ArbEG as such and therefore have no statutory right to inventor remuneration under ArbEG’s provisions, although their service agreement may provide similar financial rewards contractually.

The second inventor designated on EP’1193 and its divisional EP’2101 is Oliver Bögershausen. According to the Polytech website, Bögershausen has been at Polytech since at least 1998. Following its merger with PTSME Medizinprodukte GmbH in mid-2011, Bögershausen was appointed company director of Polytech. Consequently, it is not clear if Bögershausen was an employee and thus entitled to inventor remuneration since the critical time point is when the invention was actually made, not when the patent application covering it was filed — EP’1193 was filed in October 2011.

So, it can certainly be concluded that it was very senior members of the Polytech team that were named as inventors on the patent. Bögershausen has a long tenure at Polytech, but O’Leary only there a few years from 2008 to 2013, so potentially already after the distribution arrangement with Silimed had ended. It is not clear whether the Polytech inventors were remunerated for their inventive contributions or not. Their seniority in the company may mean that ArbEG never applied.

As previously mentioned, ArbEG inventor remuneration is calculated based on international profits. An article by RNA Law, a Brazil-based law firm focused on IP matters, refers to an international patent enforcement campaign it is handling on behalf of Silimed. Does that mean Silimed is seeking patent transfer and enforcement in all countries the patent is in force? Must ownership entitlement and enforcement always be handled in separate proceedings in each country? Will all countries come to the same conclusion? Will Polytech settle? Who will pay the annual patent renewal fees in the mean time? Silimed was registered as the new patentee for the German patent of EP’1193, but similar transfers have not yet been found to be recorded in other countries. Will Silimed designate new (the true?) inventors in any country after the patent has been recorded in their name? Under US law, an incorrect inventor designation can be fatal for the US patent — how could that point be resolved? Or will this complexity essentially make the US patent too expensive to even use for enforcement?

According to an article by Valor International, Silimed filed a law suit against Polytech in Brazil in 2021 in view of the granted Brazilian counterpart patent there, but this suit has not yet progressed beyond the initial stages. The article states that Silimed was using the patented process in the early 2000s already. The article implies that Silimed had taken a relaxed approach to the improved process, not filing a patent application on it. But is this what really happened?

Dieburg fights back

So, it was looking like Silimed had the upper hand, but we all know from football that the German competitive temperament is never to give up, even when you are down. It was in November 2024 when the Oberlandesgericht (OLG or Higher Regional Court) in Frankfurt concluded that Silimed was in fact entitled to the patent EP’1193. Faced with the prospect of an infringement suit from the very patent it had filed and paid for, Polytech tried to reverse the decision on entitlement. So, this is what happened in 2025 — the missing year.

The Oberlandesgericht in Frankfurt had refused to grant leave for a revision of its decision, which is an appeal on points of law, to the Bundesgerichtshof (BGH or Court of Justice) in Karlsruhe. In other words, Polytech was blocked from requesting a revision of the entitlement decision. However, under German law, where leave for a revision is refused, a party may nevertheless appeal this refusal via a Nichtzulassungsbeschwerde, which is a complaint asking the Bundesgerichtshof to decide whether a Revision should nevertheless be allowed. The Bundesgerichtshof decides whether the legal issues are sufficiently important to justify hearing a revision at all.

Polytech therefore filed the complaint against the decision refusing a revision before the Bundesgerichtshof, arguing they should be allowed Revision proceedings on the entitlement decision. Sadly for Polytech, on 16th December 2025, the Bundesgerichtshof dismissed that complaint. As a result, there was never a Revision, and the Oberlandesgericht Frankfurt’s judgment from November 2024 became final. It was on 5th January 2026 that the ruling of the Bundesgerichtshof dismissing the complaint was served on the parties and from that moment onwards, Silimed legally became the proprietor of the European patent. The stage for the infringement battle was finally set…

A battle over the Unified Patent Court

So, if you thought that was exciting, it was only in 2026 that things really started to heat up! Clearly, Silimed wanted to use the Unified Patent Court (UPC) and aim for a decision of infringement in multiple EU countries via a one-stop shop. Prior to the UPC, almost all patent enforcement proceedings in Europe occurred on a country-by-basis. Whilst the UPC is currently only in force in 18 EU countries, which is less than half of all EPC contracting states, it is nevertheless a huge step forward from the previous enforcement regime. With the expanded freedoms in long-arm jurisdiction following the EU Court of Justice’s ruling in BSH Hausgeräte in 2025, an EU national (and therefore also UPC) court’s judgment against Polytech could now potentially also extend to countries outside the territories of the EU and UPC.

However, back in March 2023, before the UPC went live, Polytech had filed an opt-out of EP’1193 under Art. 83 UPC Agreement (UPCA), removing the patent from the jurisdiction of the UPC. The opt-out regime is a transitionary scheme until 2030 allowing users of the EPO system to escape the reach of UPC and rely on the tried and tested national system. Whilst the national route is never closed off, opting a patent out of the UPC means that the risk of a UPC central revocation action from a competitor has been nullified. The possibility for an EPO opposition proceedings are unaffected by an opt-out, but the EPO opposition must strictly be filed within a 9 month time-window after EP patent grant. A UPC revocation action can be filed at any time — that is the catch.

This March 2023 time point was before the patent ownership entitlement proceedings in Germany had been resolved, but after the ICC arbitration had ruled in Silimed’s favour. However, many patent owners made use of the sunrise period before the UPC actually started business in June 2023 (preventing a flood of opt-outs on the court’s very first day), so Polytech’s opt-out timing here seems relatively unremarkable.

Silimed didn’t rest on its laurels after becoming the legal owner of the patent. Two days’ later on 7th January 2026, Silimed sent a warning letter to Polytech explaining that a national revocation action could block the UPC opt-out withdrawal pursuant to A.83(4) UPCA. The day after that, Silimed then sent a cease-and-desist letter (Abmahnung) to Polytech alleging infringement of EP‘1193 and demanded that Polytech give undertakings, which means Silimed asked Polytech to sign a binding contract in which Polytech would agree to not perform certain acts (patent infringement) and specifying penalty clauses (typically substantial monetary fines) in case Polytech would breach that contract and perform said acts.

On 4th February 2026, it sought to withdraw the opt-out so that it could pursue central infringement proceedings before the UPC. At first glance, this appeared straightforward.

However, on 9th January 2026, only one day after Polytech had received the cease-and-desist letter, PT H&A Management GmbH, an affiliate company belonging to the same group of companies as Polytech, had filed a revocation action (Nichtigkeitsklage aka nullity action) vis-a-vis the German part of EP’1193 before the Bundespatentgericht (German Federal Patent Court, BPatG). The value of the dispute was set at 1 million euros. Commencing these national revocation proceedings had far-reaching consequences. Indeed, Art. 83(4) UPCA provides that an opt-out cannot be withdrawn once national proceedings concerning a part of the EP patent have already been “brought”.

Polytech’s apparent strategy was simple:

maintain the original UPC opt-out filed in 2023;
file a national revocation action in the name of a different legal entity;
argue that the UPC opt-out could therefore never be withdrawn in view of Art.83(4) UPCA;
permanently prevent the new proprietor from accessing the UPC;
avoid a centralised UPC enforcement action.

The day following the request for UPC opt-out withdrawal i.e. on 5th February 2026, Silimed:

commenced German national infringement proceedings before the Munich Regional Court (Landgericht München) against Polytech. Remember that German national law has bifurcated infringement and invalidity proceedings so Silimed’s infringement proceedings before the Landgericht München are entirely separate from PT H&A’s revocation action in relation to the same patent before the BPatG. Silimed requested a preliminary injunction in relation to Polytech’s activities vis-a-vis the subject matter of their formerly owned patent; and
filed a central infringement action against Polytech before the UPC’s Hamburg Local Division. This represented the major strategic step because the UPC action sought relief extending across all the participating EU states, rather than only Germany. There are actually nine more countries (AT, BE, DK, FI, FR, IT, NL, PT and SE) in which both the UPC and EP’1193 are in force, although at the time of writing this article, recordal of the transfer to Silimed was only found to have been effected in four of these countries (DK, FI, NL and PT) in addition to Germany. Incidentally, Silimed’s UPC infringement claim was not only to Polytech, but also to eight distributors of the accused implants from across Europe.

In relation to the UPC infringement action (1), Polytech, as the defendant, submitted Preliminary Objections on the jurisdiction of the UPC. Indeed, Polytech was of the opinion that national proceedings concerning the patent had already been “brought” — that PT H&A’s national revocation action in Germany had been filed before Silimed withdrew Polytech’s 2023 UPC opt-out in February 2026.

Tug of war over an opt-out

Did this defence begin to cause Silimed some serious concern? Was Polytech actually going to successfully block them from using the UPC even though Polytech had filed a patent on an invention that had been deemed to not even be theirs?! It was on 4th February 2026 when Silimed had lodged the application to withdraw the UPC opt-out. However, looking to hedge its bets, on 7th April 2026, Silimed lodged an application for removal of the opt-out registered by Polytech in 2023, arguing that the 2023 opt-out application had been filed without authorisation. Indeed, Silimed argued that following the final decision of the Oberlandesgericht Frankfurt, made final on 5th January 2026, Polytech had been deemed never to have been entitled to EP’1193 and the invention to which the patent relates — thus ab initio.

The UPC registrar however pointed out that the opt-out was already effectively withdrawn by the Applicant on 4th February 2026 and therefore their April removal request was rejected. Silimed appealed this to the UPC Court of Appeal in Luxembourg requesting the registrar’s decision on the removal request be reviewed. On 29th June 2026, Judge Grabinski looked at Silimed’s request regarding the opt-out — both the request for its withdrawal and its removal. Grabinski ruled that since the parties in the entitlement dispute had agreed to use German law to decide on entitlement of all national parts of the EP’1193, the decision of the Oberlandesgericht Frankfurt dated November 2024 only provided for a claim to transfer the European patent from the non-entitled proprietor to the entitled proprietor — not for unwinding acts retroactively. Consequently, that German decision on entitlement did not mean that Polytech was not entitled to file the opt-out of EP’1193 in 2023. So, Silimed’s line of defence that the original UPC opt-out from 2023 was invalid, didn’t fly.

On 7th May 2026, the UPC’s Hamburg Local Division (LD) upheld the Preliminary Objection filed by Polytech as defendant in the infringement proceedings — the Hamburg LD held that the UPC lacked jurisdiction. So, Silimed’s UPC infringement action was dismissed. Polytech seems to have effectively shut Silimed out of enforcement via the UPC by cleverly having an affiliate prevent opt-out withdrawal.

Who is the proprietor of unlawfully acquired intellectual property?

The UPC result all turned on the finding that the German ownership entitlement decision wasn’t actually retroactive. Essentially, everything Polytech had done in relation to the patent prior to losing legal ownership on 5th January 2026 could not be deemed void nor found invalid — it had to be respected or actively undone.

On the face of it, doesn’t it all seem terribly unfair?! For example, the following topics come to mind:

In arbitration, it had been decided that confidential information and trade secrets had been misappropriated and then the German national court decided that the patent should belong to Silimed. The implication was that Polytech had recognised the commercial value of Silimed’s improved silicone implant manufacturing process and patented it as if it was their own. So, how can it be fair and just for all actions relating to that patent ab initio be upheld and respected, despite it already having been deemed relating to unlawfully acquired intellectual property?
Did Silimed make a strategic error by agreeing to German law to decide on the ownership of a European bundle patent for all countries in which EP’1193 is in force? Would a different law have resulted in a different outcome? Was a different law even an option?
The month that elapsed between Silimed effectively becoming the legal owner on 5th January 2026 to Silimed withdrawing the opt-out: were they waiting to be recorded as proprietor on the patent register? The evidence is that this seems to have only first occurred on 23rd February 2026 for the German part of EP’1193. Was this procedural step leaving Silimed at a massive disadvantage — they were legally the patent owner, but yet seemingly unable to act? Were they truly unable to withdraw the opt-out nor file the UPC infringement action before 4th February 2026? Is it justified for that simple clerical step of the recordal to result in such a huge disadvantage?
Rule 8.5 UPC applies a rebuttable presumption that the registered proprietor at the time of an opt-out was authorised to file it. Clearly this rule is there to open the door to solve the problem of unauthorised opt-outs. So why doesn’t this case fall squarely within that bucket? Had Silimed’s actions somehow closed off this option? If this case isn’t sufficient to rebut the presumption, what case would even meet this threshold?!

Let’s start with topic (1): what is the logic behind all actions relating to that patent ab initio be upheld and respected even though the patent owner apparently hadn’t been entitled to the patent when those actions had occurred? Well, many countries have chosen this option, and the main reason is legal certainty for third parties. Think of everything that the patentee may have done prior to the decision on entitlement — executed licenses, obtained damages from enforcement, abandoned certain countries. Deeming those transactions null and void wouldn’t be fair on those licensees, infringers and those suddenly freed from an FTO issue.

So, moving to topic (2) on choice of law. Firstly, let’s go back to basics. A European patent is a bundle of national patents — this can be derived from Art. 2 and 74 EPC. In this context, the countries that signed up to the European Patent Convention have essentially outsourced the grant proceedings (plus a few extras, like post-grant opposition) to the centralised body, the EPO, for all cases filed there. The benefit is lower cost and convenience to applicants who no longer need to file at and negotiate with all the different national patent offices (each having their own language and special requirements) because the EPO does it all in one centralised proceedings. However, post-grant, the EPC has limited provisions.

In that case, how did Silimed achieve the entitlement and transfer of the entire bundle of national patents in EP’1193 by one single national (German) court? Well, there is actually no basis in the EPC covering entitlement disputes for granted European patents. Art. 61 EPC is only relevant for pending EP applications — presumably Silimed will use this route at some point to transfer the pending divisional EP’2101, which is currently ‘on hold’ and still in Polytech’s name (and incidentally was opted out of the UPC at the same time as the parent). So, theoretically speaking, due to the absence of an EPC provision on entitlement of EP patents, Silimed would have had to have pursued entitlement proceedings in all the EPC contracting states — nearly 20 countries!

However, Art. 60 EPC does give some hints — the second sentence of this Article essentially says that the right to an EP patent is governed by the law of the country in which the inventor is employed. Indeed, this is the provision that the German Bundesgerichthof relied on in 2023 in a dispute about the entitlement to a patent relating to form-seal plastic bags (decision X ZR 75/21). In the plastic bag case, the German court allowed not only the German part of the EP patent be transferred to its deemed rightful owner, but all the other national patents in the EP bundle as well. Of course, the Silimed v. Polytech situation is slightly different in that Silimed’s (deemed rightful) inventors were (presumably) in Brazil and consequently Brazilian law would be relevant to them. However, Polytech, the defendant, is domiciled in Germany, so doubtless this element played a role in why Silimed selected a German court for the entitlement proceedings. In fact, maybe they had accepted they may only be successful in transferring only the German part of EP’1193 from Polytech to Silimed?

Relying on Art. 60, second sentence EPC, the argument is essentially that if Polytech’s ‘inventors’ were employed (or were company directors) in Germany, then the original right to EP’1193 (before the 2024 entitlement decision) was per German law and therefore counted for all EPC states in which EP’1193 was in force — so the reverse must also be true to unwind that chain of title. So, whilst this 2023 Bundesgerichthof plastic bag decision is not without its critics, both Silimed and Polytech actually actively agreed to German law in the German entitlement proceedings that commenced in 2017. The 2023 Bundesgerichthof plastic bag decision made it easy for the Oberlandesgericht Frankfurt in November 2024 to order the transfer of all EP national patents to Silimed and not just the German part. Indeed, it was actually the same Oberlandesgericht Frankfurt that had already decided the plastic bag decision in July 2021 — it had then been confirmed by the Bundesgerichthof in 2023.

So, that is how we got from a mere German national court decision on ownership entitlement to pan-EPC ownership legal effect.

So, why wasn’t Silimed deemed patent owner from the filing date onwards?

According to the UPC’s court of appeal decision, Judge Grabinski notes in point 24 of the Reasons that it was Art. II(5)(1) of the German Law on International Patent Conventions (IntPatÜG) that was the basis for transfer of the European patent by the Oberlandesgericht Frankfurt in November 2024. That provision in IntPatÜG gives the entitled person a claim to a transfer of the patent, rather than declaring that the patent always belonged to that person, Grabinski thus concluded that the German Oberlandesgericht Frankfurt judgment did not operate retroactively (ab initio). Instead, ownership changed starting from when the entitlement judgment became effective (ex nunc). That is why Polytech's earlier acts—such as filing the UPC opt-out in March 2023—were not retrospectively invalidated.

So, are there any laws that Silimed could have chosen instead that would have resulted in retroactive effect of the patent entitlement? French law seems to adopt a different approach from the German regime. Under Article L611-8 of the French Intellectual Property Code, a person claiming to be entitled to a patent application or granted patent may bring an action en revendication to recover ownership. In his online treatise Propriété industrielle, published on the Livv legal research platform, Prof. Louis Vogel explains that a successful action en revendication transfers ownership of the patent to the claimant and « produit un effet rétroactif », with the claimant deemed to have been the owner of the patent from the outset. Indeed, the cour de cassation (France's highest court for civil and commercial matters) has held that a successful claimant is entitled to the net financial benefit derived from exploitation of the invention, whilst at the same time protecting any party that acted in good faith from having to repay income received before it became aware of the competing ownership claim. If French law had governed entitlement to EP'1193, this raises the intriguing question whether Polytech's March 2023 UPC opt-out could have been regarded as having been filed without authority because, following the retroactive transfer of ownership, Polytech would be treated as never having been entitled to the patent?

But would the parties even have agreed to French law when the entitlement proceedings were commenced in 2017? The UPC was still a long way off back then and possibly in the process of being derailed by the Brexit vote. In the Hamburg UPC Local Division decision (CFI-481/2026) from the 7th May 2026, from Silimed’s infringement action, there were co-defendants from EPC countries AT, BE, NL, PT, CZ, ES, IT and GB. So, it seems that France wasn’t a priority in this dispute, even though the patent was in force there?

Reviewing the first Oberlandesgericht Frankfurt decision from November 2020, it seems that only then were the parties pushed to decide on a governing law in the entitlement dispute. Silimed was pushing for Brazilian law at this stage in view of their (‘true’) inventors being based in Brazil and that law’s connection with the second sentence of Art. 60 EPC. However, in the end, the parties decided on German law — maybe the potential implications of this on the UPC were too remote to be high priority.

To close the loop on this point, Art. 49 of the Brazilian Industrial Property Law (Law No. 9.279/96) provides an entitlement remedy in an entitlement dispute and states: "No caso de inobservância do disposto no art. 6º, o inventor poderá, alternativamente, reivindicar, em ação judicial, a adjudicação da patente.” Translated: where Article 6 has not been complied with, the inventor may alternatively seek, by judicial action, adjudication of the patent. However, it is not clear whether such “adjudication” provided for in Art. 49 would provide any advantages versus German law.

And what about Rome II?

Well, Rome II is an EU conflict-of-laws regulation. It tells a court which national law to apply when a dispute involves more than one country and the dispute does not arise from a contractual relationship. Art. 14 of Rome II permits parties to choose the law and is the provision the Oberlandesgericht Frankfurt relied on when both parties chose German law for the entitlement proceedings. Art. 8 of Rome II however mandates the lex protectionis for IP infringement matters meaning that Art. 14 cannot be used — so the parties cannot choose the law governing IP infringement proceedings. Also, the effect of Art.13 Rome II actually creates uncertainty over whether patent entitlement disputes can validly be subjected to an Art.14 choice of law at all.

So, in a nutshell:

Did Silimed make a strategic error by agreeing to German law to decide on the ownership of a European bundle patent for all countries in which EP’1193 is in force? No, there were probably no better options at the time.
Would a different law have resulted in a different outcome? Possibly, but this is unlikely.
Was a different law even an option? Brazilian law was the only real justifiable/logical other option, but there is an argument that there shouldn’t have been any options at all depending on whether Rome II’s Art. 8 trumps A.60 EPC.

The power of being the named patent owner on record

Now to topic (3): the limbo month between the entitlement decision becoming legally effective and Silimed withdrawing the opt-out. Will we ever know what happened in this month? We can speculate that Silimed and team were perhaps too busy celebrating their win on entitlement to answer the calls of their lawyers. Or maybe it was all tactically well thought through? There is a JUVE Patent article that implies that Silimed was waiting to be recorded as proprietor on the patent register and only withdrew the 2023 opt-out once this recordal step had occurred. However, which patent register was meant here exactly? The UPC doesn’t have a “patent register” as such — it is a court. The EPO washed its hands of EP’1193 once the opposition period ended; EP’1193 was from 2016 onwards, a bundle of national patents. EP’1193 is currently in force in ten countries (AT, BE, DE, DK, FI, FR, IT, NL, PT and SE) in which the UPC is also in force, but at the time of writing this article, recordal of the transfer to Silimed has only been found to have been effected in five of these countries (DE, DK, FI, NL and PT) and all of these recordals occurred from 23rd February 2026 onwards — nothing earlier. So, why did Silimed wait a month? Or were they not waiting for anything? Interestingly, Prof. Hoyng on his UPC Unfiltered blog suggests that Silimed should have withdrawn the UPC opt-out on the same day as the Bundesgerichthof decision was served on the parties on 5th January 2026.

What about the rebuttable presumption under R. 8.5 UPCA i.e. topic (4)? The Rule states: “there shall be a rebuttable presumption that the person shown in each national patent register and the European Patent Register kept by the European Patent Office is the person entitled to be registered as proprietor or applicant as the case may be”. If someone wants to challenge this ownership status, then they carry the burden to overturn this presumption with sufficient counter-evidence. Grabinski kindly made it very clear that it was up to Silimed to demonstrate that either (a) Polytech wasn’t actually the named proprietor on the national patent registers on 30th March 2023 (when Polytech filed the opt-out), or, if that is not possible, that (b) Polytech was not entitled to be registered as the patent proprietor “under the law of each Member state” on 30th March 2023 and that it was in fact Silimed who was entitled.

So, essentially Grabinski’s (a) is a ‘spot the difference’ game, and Grabinski’s (b) is ‘how to spend a bucket-tonne of cash on entitlement proceedings in lots and lots of countries’ most of which probably won’t retroactively invalidate your competitor’s hijacking opt-out anyway! In fact, would Grabinski’s (b) ever even be a viable option? Surely, you’re always going to reacting to an unauthorised opt-out that has already happened? So, Grabinski’s (a) is probably only useful where someone misread the patent register — a clerical error. And Grabinski’s (b)? Well, maybe if you only have the EP patent in force in France you would have a chance for the retroactive effect? But even then, would you even want to bother with the UPC at all?

So, going through my topic (4) questions to sum up:

If Rule 8.5 UCPA exists to solve the problem of unauthorised opt-outs, why doesn’t this case fall squarely within that bucket? Well, the bucket simply doesn’t cover the situation where the EP patent was lawfully opted out by the party named as proprietor on the relevant patent registers.
Had Silimed’s actions somehow closed off the possibility to leverage Rule 8.5 UPCA to fix their problem? I think potentially if Silimed had acted much earlier, ideally already in 2013 once EP’1193 had published as a pending patent application, the situation with the UPC could have been completely avoided. It was only from the commencement of the UPC sunrise period in 2023 — a decade later — that this tactical option opened up for Polytech.
If this case isn’t sufficient to rebut the presumption per Rule 8.5 UPCA, what case would meet this threshold? I think Grabinski’s (b) would be useful in the case where party X owned a patent and final decision(s) in entitlement proceedings effective in all UPC contracting member states had already been handed down — whether one or more proceedings covering multiple national patents in the bundle, or separate entitlement proceedings in each country — transferring EPC national patents to party Y, but the patent registers hadn’t yet been updated to reflect the new ownership and party X (tactically) opted the EP patent out of the jurisdiction of the UPC at this juncture — they were named as patent owner, but legally actually not patent owner.

So, following Judge Grabinski’s decision on 29th June 2026, it seemed like the UPC was off the table for poor Silimed. What could the Brazilian company possibly do to claw back control?

Munich cracks the whip

Silimed’s warning and cease-and-desist (Abmahnung) letters to Polytech filed on 7th and 8th January 2026, respectively, seem to have been the trigger for the devastating decision by Polytech to have their affiliate file the German national revocation action preventing opt-out withdrawal. Were these letters truly a procedural necessity that was worth the risk in this scenario? Had Silimed really made a huge tactical error when sending Polytech the letters before withdrawing the opt-out? Apparently this step led to Silimed locking itself out of the UPC!

In reality, it actually seems that Silimed had been thinking ahead and each and every one of Polytech’s next steps had been anticipated, strategised and mitigated. Let’s go back a couple of years and I will explain.

In November 2024, the Oberlandesgericht Frankfurt had handed down the decision on patent ownership entitlement, which Polytech spent the next year or so before the Bundesgerichthof trying (and failing) to reverse. Silimed’s counsel apparently made good use of their time in this period to consider the options available to Polytech and which one they would likely select.

In December 2024, Silimed had the Landgericht München grant a prohibitive injunction (Unterlassungsverfügung) against Polytech. This was a special type of injunction prohibiting Polytech from:

impairing the validity of EP’1193;
impairing the patent's effect; or
impairing its enforceability;

and from inducing third parties to do any of those things.

It was essentially a preservation order (Sicherungsverfügung) and, whilst this specific ex parte court order was not made publicly available, it finds its legal basis in paragraphs 935, 938 and 940 ZPO (the German rules on civil litigation procedure) as interim protection to Silimed following the patent ownership entitlement decision by the Oberlandesgericht Frankfurt in the preceding month, which was not made final for over a year in view of Polytech’s attempts to reverse it. Indeed, it is understood that the order stated that the preservation order would be in force until one month had elapsed from the date the November 2024 Oberlandesgericht Frankfurt judgment actually became legally effective. So, in the end, the preservation order expired on 5th February 2026.

Suddenly, Silimed’s tactics become clear. The limbo month at the beginning of 2026 wasn’t indecision at all. It wasn’t Silimed asleep at the wheel. Silimed’s team knew exactly what they were doing. Indeed, Silimed knew Polytech — they had worked with them successfully for years! They knew how Polytech ticked. In my view, Silimed had set a trap, and the bait was the biggest thing that has happened to European patent law since 1973 — it was the big, fat and shiny Unified Patent Court. And Polytech apparently couldn’t resist it!

In their letter dated 7th January 2026, Silimed had expressly warned Polytech that a national revocation action could have a blocking effect under Art. 83(4) UPCA and thus render a later withdrawal of the opt-out ineffective. Silimed explicitly stated that they would consider such a revocation action an infringement of the preservation order. The paper trail was made crystal clear — Polytech were informed about the consequences of any actions they may choose take. It was spelled out in black and white (and doubtless via recorded letter with advice of delivery!).

And then came the pincer movement — the letter the following day. The cease-and-desist letter to Polytech alleging infringement of EP’1193 in Germany put Polytech under pressure. The preservation order meant they could not act, but the cease-and-desist letter meant that if they didn’t act, things might be even worse!

The UPC was relevant to TEN countries in which EP’1193 was in force. Imagine the impact and chaos if Silimed were to enjoin Polytech’s activities in all of those countries in one shot!

So, Silimed had Polytech cornered and Polytech took the bait — hook, line and sinker. And no-one suspected a thing!

It was the very next day that PT H&A had their counsel file the German revocation action at the BPatG (Bundespatentgericht or German Federal Patent Court). Bifurcation meant that this was a completely separate proceedings — there was no impact on Silimed’s infringement claim before the Landgericht München.

On the final day of the preservation order period (4th February 2026), Silimed applied to withdraw the 2023 opt-out before the UPC. On the 5th February, the two infringement suits were initiated — one before the UPC’s Hamburger Local Division and the second one before the Landgericht München.

We already know what happened with the UPC suit — the struggles with removing the opt out and devastation caused by PT H&A’s national revocation action were as clear as day for all to see.

Meanwhile, the German national infringement proceedings by Silimed as new patent owner on file continued in parallel. On 2nd April 2026, the Landgericht München granted a preliminary injunction restraining Polytech from manufacturing and marketing the accused implants in Germany.

Subsequent proceedings focused largely on enforcement of the preservation order imposed in December 2024, including allegations that Polytech had failed to comply with the court’s orders and the imposition of coercive measures against its managing director.

The Landgericht München concluded that the holding company PT H&A and Polytech were acting in concert. Indeed:

they shared common management, a common address and common commercial interests.
Polytech could have filed the German revocation action earlier;
Polytech could have waited until the preservation order had expired;
instead, PT H&A filed the revocation action immediately after Polytech received Silimed’s warning;
and Polytech subsequently relied upon that the revocation action to defeat Silimed’s attempted opt-out withdrawal before the UPC.

Importantly, the court did not criticise the filing of a national revocation action in itself. Instead, it held that the coordinated use of an affiliated company to prevent the new proprietor from accessing the UPC amounted to a breach of an existing preservation order explicitly designed to preserve the patent’s enforceability.

The court considered that conduct to be an abuse of procedure solely designed to frustrate the rights of the new patent owner.

Jail time?!

Perhaps the most remarkable aspect of the judgment concerns enforcement. On 22nd May 2026, rather than imposing a financial penalty, the Landgericht München ordered coercive imprisonment (Ordnungshaft) against the managing director of Polytech. The tenor of the judgment states (English translation):

“An order of detention for a period of ___ months is imposed;

in the alternative, in the event that such detention cannot be enforced, against the managing director of the judgment debtor,

an order of detention for a period of ___ months is imposed;

in the alternative, in the event that an order of detention cannot be enforced, a coercive fine of EUR ?00,000.00 is imposed on the judgment debtor.

Enforcement shall cease as soon as the action for a declaration of invalidity [Nichtigkeitsklage], case no. ___, is withdrawn and the debtor declares that it does not derive any rights from that action for a declaration of invalidity or from the opt-out declaration of 30 March 2023.”

Indeed, the court considered that the commercial value of the dispute significantly exceeded the maximum statutory fine available under German law — 250,000 euros. A financial sanction would not therefore have sufficient coercive effect in this case.

Although such an imprisonment order does not necessarily result in immediate detention if compliance follows, it illustrates the seriousness with which German courts may respond to attempts to circumvent judicial orders.

One can only imagine how Polytech’s managing director felt the moment he learned of the judge’s enforcement order and how quickly he was able to decide on what to do next!

Was it this shock and awe tactic that Silimed had sought from the beginning or was this merely an unexpected icing on the cake?

Who controls the where

This case demonstrates that the UPC has fundamentally changed European patent litigation.

Increasingly, litigation is not simply about whether a patent is valid or infringed. It is also about who controls the forum in which those questions will be decided.

For many businesses, access to the UPC means:

pan-European injunctions;
centralised damages claims;
consistent decisions across multiple Member States;
significant reductions in litigation costs compared with parallel national proceedings;
the long-arm jurisdiction element stretching UPC decisions beyond its borders.

Preventing access to that forum can therefore become a strategic objective in its own right.

For Silimed, however, it seems that everyone assumed they would want to use the UPC. That assumption was what gave them control.

After BSH Hausgeräte, claimants don’t necessarily need enforcement before the UPC to make use of the new long-arm landscape in the EU. For Silimed, maybe enforcement in Germany was enough? Indeed, Germany was the source of their troubles with Polytech.

The case is far from over, we will see what happens next!

Sources of information and further reading:

JUVE Patent: part of the German publishing house JUVE Verlag in Cologne covering legal, tax and patent professions.
Valor International: the English language publication of Valor Econômico, Brazil’s leading business, finance and economics newspaper.
Hoyng Rokh Monegier: UPC Unfiltered, by Willem Hoyng.
IP Fray: reporting and commentary on IP disputes and debates.
RNA Law: Brazilian boutique law firm exclusively dedicated to IP.
Bristows’ podcast: You, Me & the UPC.
Prof. Louis Vogel’s Propriété industrielle, published on the Livv legal research platform.