The single most active filer in GreyB’s EPO opposition dataset, spanning 2021 to 2026 across all sectors, isn’t Teva, Sandoz, Nicoventures, or Philip Morris. It’s Strawman Limited, with 210 recorded filings. It manufactures nothing, licenses nothing, and has no commercial interest in any of the patent families it opposes. It exists to conceal the party that does.
That one data point, more than any filing volume or revocation rate, shows what EPO opposition data is actually measuring: not just which patents attract challenge, but how much of that challenge has been removed from view by design.
GreyB’s analysis covers opposition filings across the medical and pharmaceutical, tobacco, food, and standard-essential patent segments from 2021 to 2026. Across 2,000-plus recorded oppositions in the top-opponent set alone, three structural patterns hold across every domain. Activity concentrates around a small number of repeat challengers. Law firm market share mirrors that concentration. And the strategic logic driving each domain differs enough that a monitoring posture built for one will misread the others.
What follows is a sector-level reading of what the data shows and the market context that explains it.
Pharmaceuticals: Teva Filed 113 Oppositions in Five Years.
The medical and pharmaceutical segment carries the highest opposition volume in the dataset and the most organized infrastructure for executing challenges at scale.
Top 10 Opponents, Medical and Pharmaceutical (2021 to 2026)
| Opponent | Oppositions Filed |
| Teva Pharmaceutical Industries | 113 |
| Strawman Limited | 112 |
| Generics Limited | 107 |
| Sandoz | 94 |
| Maiwald GmbH | 74 |
| Stada Arzneimittel AG | 63 |
| Elkington and Fife LLP | 56 |
| Hamm & Wittkopp | 55 |
| Essity | 55 |
| Sanofi | 50 |
Teva, Sandoz, and Generics Limited are three of the world’s largest generic and biosimilar manufacturers, each operating in a business model where speed to market after originator patent expiry directly determines revenue capture. A blockbuster compound generating $2 billion or more annually in branded sales can see generic entrants collectively capture 80 to 90% of volume within 12 months of exclusivity loss. Against that backdrop, an EPO opposition that revokes or narrows a secondary patent, a formulation claim, a dosing regimen, or a polymorphic form covering a compound already off primary patent protection removes a barrier that would otherwise delay or prevent market entry entirely.
First-instance EPO proceedings through oral hearing typically cost in the range of €50,000 to €250,000, depending on complexity, against a contested U.S. Hatch-Waxman case that routinely runs to eight figures per side through trial. The EPO is not a fallback route for generic challengers. It’s the first-choice forum for clearing secondary patent protection before committing to expensive parallel litigation.
The Strawman Problem
Strawman Limited’s second-place ranking in the pharmaceutical table, at 112 filings, sits one position and one filing below Teva. At 210 filings across all domains, it is the dataset’s most active single opponent. A strawman opposition is filed by a named intermediary to keep the real challenger off the public record, and is used where direct filing would alert the patentee to a market-entry timeline, expose a licensing position, or create an adverse inference in concurrent proceedings.
The pharmaceutical sector’s heavy use of this mechanism, with a strawman entity ranking alongside the largest named generics manufacturers, means the visible opposition record understates competitive pressure in a measurable way. Where Strawman Limited appears as the opponent, the downstream question of who instructed it, and against which patent family and for what commercial reason, is not answered by the EPO register. Separate intelligence is required to bridge that gap.
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Six of the Top Ten Pharma Opposition Firms Are German. The UPC Has Made That Concentration More Consequential.
Top 10 Law Firms, Medical and Pharmaceutical (2021 to 2026)
| Law Firm | Oppositions Handled |
| Elkington and Fife LLP | 235 |
| Hoffmann Eitle | 172 |
| Hamm & Wittkopp | 170 |
| Kraus Lederer Partg MbB | 149 |
| Maiwald GmbH | 146 |
| D Young & Co LLP | 144 |
| Ter Meer Steinmeister & Partner | 109 |
| Carpmaels & Ransford LLP | 104 |
| Mewburn Ellis LLP | 72 |
| DF-MP Patentanwälte Rechtsanwälte | 70 |
Elkington and Fife LLP leads at 235 matters, 63 ahead of second-placed Hoffmann Eitle. The firm handles opposition work for multiple generic challengers across the same technology areas, which means its docket reflects the sector’s structure as much as any individual client relationship. Six of the top ten firms by volume are German or have substantial German prosecution practices. This reflects the EPO’s Munich-centered procedural architecture, where first-instance opposition proceedings, including oral proceedings before the Opposition Division, run through the EPO’s Munich office, and where technically trained German patent attorneys with direct EPO procedural experience carry the core argumentation load.
UK firms, D Young and Carpmaels and Ransford in particular, appear alongside the German practices because the largest generic challengers, including Teva and Sandoz, run global prosecution and litigation portfolios that require coordination across European jurisdictions and, since 2023, across the Unified Patent Court. A pending EPO opposition now factors directly into UPC preliminary injunction analysis: the EPO’s provisional view on validity, expressed at oral proceedings or in interim communications, is material to whether the UPC grants or refuses interim relief against an allegedly infringing product. The same law firms managing EPO oppositions are increasingly managing that cross-forum coordination.
Tobacco: BAT and PMI Settled in 2024. EPO Opposition Filings Have Not Slowed.
Where pharmaceutical opposition is distributed across dozens of compounds, disease areas, and challenger entities, tobacco opposition resolves almost entirely into a single bilateral contest over the heat-not-burn category: BAT against Philip Morris International.
Top 10 Opponents, Tobacco (2021 to 2026)
| Opponent | Oppositions Filed |
| Nicoventures Holdings Limited | 177 |
| Philip Morris | 143 |
| GD Spa | 75 |
| JT International SA | 65 |
| Imperial Tobacco | 62 |
| Focke & Co GmbH | 19 |
| Smokeless World GmbH | 13 |
| Weickmann & Weickmann Partnership | 13 |
| Körber Technologies GmbH | 9 |
| Frederik Behrends | 7 |
Nicoventures Holdings Limited, BAT’s next-generation product subsidiary, filed 177 oppositions over the five-year period. Philip Morris filed 143. Together, they account for over half of all tobacco opposition activity in the dataset. In the 2025 to 2026 single-year view, Nicoventures leads with 60 filings, and Philip Morris follows with 52, rates close to their five-year averages, showing no wind-down.
The commercial context is important. PMI’s smoke-free products generated 41% of its total net revenue in the first half of 2025, with over 41 million users worldwide across its IQOS heated tobacco, ZYN nicotine pouch, and VEEV e-vapor lines. BAT’s equivalent smoke-free segment, spanning Vuse, Velo, and glo, reached approximately 24 million consumers in the same period. Both companies are in the process of replacing a combustible business with a next-generation one, and the patent architecture around heating elements, consumable designs, and device-to-consumable interfaces directly determines which products can be brought to market in which territories without licensing exposure. A broad granted patent in this space is not a peripheral IP asset. It’s a potential injunction mechanism affecting the primary revenue driver for both companies.
The dispute began publicly in 2018 when Philip Morris filed patent infringement proceedings in Japan against BAT’s Glo device. BAT countered in 2020 with actions at the U.S. International Trade Commission and lawsuits in Germany and the UK. By February 2024, when a global settlement was announced covering all pending infringement litigation over then-current heated tobacco and vapor products, the EPO opposition pipeline the two parties had built against each other’s grants already extended years into the future.
What the Settlement Did Not End
The 2024 settlement was scoped to products in the market at the time of signing. It resolved infringement claims over existing designs and lifted related injunctions and exclusion orders. It did not reach EPO proceedings filed against patents covering next-generation product architectures, because those proceedings concern rights relevant to products not yet commercialized at the time of settlement.
The 2025 to 2026 filing volumes confirm the gap the settlement left. Both parties continue to challenge each other’s EPO grants at rates nearly identical to the five-year average. Nicoventures filed 60 EPO oppositions in that 12-month period. Philip Morris filed 52. The category’s next design generation, the products both companies will bring to market over the next three to five years, remains contested at the EPO regardless of what was agreed in 2024.
D Young Leads Tobacco Opposition Work With 101 Matters. The Firm-to-Client Mapping Is Direct
Top 10 Law Firms, Tobacco (2021 to 2026)
| Law Firm | Oppositions Handled |
| D Young & Co LLP | 101 |
| HGF Limited | 66 |
| Dehns | 52 |
| Bugnion SpA | 48 |
| Mewburn Ellis LLP | 47 |
| Grunecker Patent und Rechtsanwälte | 30 |
| Bandpay & Greuter | 29 |
| Meissner Bolte | 26 |
| Venner Shipley LLP | 24 |
| Ezio Bianciardi | 21 |
D Young & Co LLP leads at 101 matters, consistent with its long-standing role as primary EPO opposition counsel for Nicoventures. HGF Limited at 66 handles the majority of Philip Morris’s EPO opposition work. The two leading law firms map directly onto the two leading opponents. Bugnion SpA ranks fourth with 48 matters, reflecting GD Spa’s position as the third most active tobacco opponent with 75 filings.
GD Spa is an Italy-based manufacturer of tobacco machinery and packaging equipment, and its opposition activity covers process and apparatus patents rather than product formulations, showing that the patent contest in heat-not-burn extends into the supply chain and manufacturing layer, not just the finished product.
Food and Nutrition: Nutricia and Nestlé Are Challenging Each Other’s Formulation Patents at Scale
The food sector opposition record has a narrower cast of challengers than pharmaceuticals and a tighter geographic cluster than any other domain in the dataset. The top two opponents, Nutricia at 64 filings and Nestlé at 62, together account for more than 40% of the top-ten food opponent volume.
Top 10 Opponents, Food (2021 to 2026)
| Opponent | Oppositions Filed |
| Nutricia (NV Nutricia) | 64 |
| Nestlé | 62 |
| Fresenius | 32 |
| FrieslandCampina BV | 24 |
| Arla Foods Amba | 21 |
| Fresenius Kabi GmbH | 18 |
| DSM BV | 17 |
| Cargill | 12 |
| Abbott | 11 |
| Danone | 11 |
The concentration at the top is explained by the specific category these companies compete in. Nutricia (a Danone subsidiary) and Nestlé are the two largest players in clinical nutrition and specialized infant formula globally. Both sell products that compete on the same formulation claims, health outcomes, and regulatory approvals. A patent over a specific oligosaccharide blend, a protein hydrolysate ratio, or a lipid composition in an infant formula or enteral nutrition product can translate directly into market exclusivity in a category where product switching is low, and shelf life in formularies is long. The pattern of Nutricia and Nestlé filing against each other’s grants is the expected output of two companies with near-identical product portfolios competing for the same formulation exclusivity.
Fresenius and Fresenius Kabi appear separately in the table and together represent 50 filings, concentrated in clinical and enteral nutrition. Both operate in the hospital and home care nutrition space, where Nutricia and Nestlé Health Science are also present, which explains the overlap in opposition targets.
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Fresenius Kabi and FrieslandCampina File Opposition Proceedings Without External Counsel. Both Appear in the Firm-Level Rankings.
Top 10 Law Firms, Food (2021 to 2026)
| Law Firm | Oppositions Handled |
| Nederlandsch Octrooibureau | 62 |
| Fresenius Kabi | 49 |
| D Young & Co LLP | 25 |
| FrieslandCampina | 24 |
| Sebastian Strych | 20 |
| Elkington and Fife LLP | 19 |
| Boult Wade Tennant LLP | 18 |
| Potter Clarkson | 16 |
| Hoffmann Eitle | 13 |
| Plougmann Vingtoft | 11 |
Two of the top five entries in this table are corporate entities, not law firms. Fresenius Kabi at 49 matters and FrieslandCampina at 24 both appear because they file opposition proceedings directly under their own representation rather than through external patent attorneys. This is not an administrative quirk. It reflects in-house EPO opposition capacity built and maintained at a volume that places these companies in the same bracket as specialist boutiques. Building that internal capability requires dedicated technical staff with EPO procedural experience, active docket management, and sustained investment across multiple years. The presence of two large food companies in a firm-level ranking is a reliable indicator that EPO opposition is treated as a core business function rather than an occasional external instruction.
Nederlandsch Octrooibureau leads the law-firm table with 62 matters. Both FrieslandCampina and Nutricia are Netherlands-headquartered, and the Dutch dairy and infant nutrition industry, including companies like FrieslandCampina, Nutricia, and DSM, sits in a relatively tight geographic cluster in the Netherlands. The concentration of EPO opposition activity in this sector through a single dominant Dutch practice reflects both the geographic proximity of the main challengers and the firm’s sustained specialization in this category.
SEPs: The Most Active Opponent Is a Licensing Vehicle.
The standard-essential patent segment is the smallest by volume in the dataset, but the profile of challengers is more varied than in any other domain, and the motivations are distinct.
Top Opponents, SEP (2021 to 2026)
| Opponent | Oppositions Filed |
| 3G Licensing SA | 17 |
| Oppo | 14 |
| Nokia | 9 |
| Unified Patents LLC | 7 |
| Ericsson | 4 |
| Bardehle Pagenberg Partnerschaft | 3 |
| Verifone Inc | 3 |
| Wisdom Fulcrum Technology | 3 |
3G Licensing SA leads with 17 filed oppositions. It is a patent licensing vehicle, not a product manufacturer or network operator. Its position at the top of the SEP table reflects a motivation structure different from the other three domains: the goal is not market entry or competitive exclusion in a product market. It is portfolio positioning in advance of, or during, licensing negotiations. Challenging a rival licensor’s SEP at the EPO can remove granted rights that would otherwise anchor a royalty demand, reframe the essentiality ratio in a portfolio comparison, or introduce validity risk that affects the negotiating posture of a patent owner seeking a FRAND rate.
Track opposition activity that can impact product launches, enforcement decisions & legal exposure.
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Oppo, with 14 oppositions, is the most active device manufacturer in the table. As a Chinese OEM seeking European market access, Oppo faces FRAND royalty demands from multiple SEP holders, and EPO opposition is one mechanism for reducing the pool of asserted rights. Nokia at 9 and Ericsson at 4 both appear as opponents, which means established licensors are challenging one another’s SEP grants, not only defending against implementer challenge. This cross-licensor opposition pattern reflects the competitive dynamics of bilateral FRAND negotiations between major holders, where the relative size and quality of each party’s portfolio directly determines the royalty rate or cross-license terms.
Top 10 Law Firms, SEP (2021 to 2026)
| Law Firm | Oppositions Handled |
| Metroconsult Srl | 17 |
| Hoffmann Eitle | 10 |
| Samson & Partner Patentanwälte | 7 |
| HGF Limited | 7 |
| Nederlandsch Octrooibureau | 4 |
| Vossius & Partner | 4 |
| Bardehle Pagenberg | 4 |
| Wuesthoff & Wuesthoff | 4 |
| Gulde & Partner | 3 |
| Cohausz & Florack | 3 |
Metroconsult Srl leads at 17, its volume mapping directly onto 3G Licensing SA’s filing activity. Unified Patents LLC appears as an opponent with 7 filings. Its model is to aggregate opposition funding from implementer members, each facing the same royalty demands but preferring not to appear individually on the EPO record, for the same reasons the pharmaceutical sector uses strawman entities: direct filing would expose commercial intent to the patent owner at the moment the opposition is filed. The SEP table, like the pharmaceutical table, contains a structured anonymity layer. The visible opponents don’t represent the full set of commercial interests in the outcomes.
The Top Three Opponents Now Account for 31% of Total Filings.
Nicoventures Filed 35 EPO Oppositions Per Year on Average. This Is a Program, Not a Response.
In the 2025 to 2026 single-year view, Nicoventures (60), Philip Morris (52), and Strawman Limited (48) together account for roughly 31% of top-20 opponent activity across all domains. Over the full five-year period, the same three entities account for approximately 26% of top-20 activity. The share held by the most active challengers is rising, not spreading.
The implication is structural. Nicoventures filed 177 EPO oppositions over five years, roughly 35 per year, which requires a functioning internal program: dedicated patent professionals tracking competitor grants within the nine-month opposition window, external counsel relationships managed across multiple jurisdictions, and a systematic decision process for which grants to target. Teva and Generics Limited have maintained consistent volumes of pharma opposition over the same period. These aren’t reactive campaigns triggered by individual grants. They’re continuous programs running against competitor portfolios in real time.
Five Firms Lead EPO Opposition Work Across Three or More Sectors. The Rest of the Market Handles What They Leave.
Hoffmann Eitle, Maiwald GmbH, D Young & Co, Elkington and Fife, and HGF Limited appear at the top of multiple sector tables. Of the roughly 50 law firms appearing in the sector-level top-ten rankings across this dataset, five account for leadership positions in three or more domains. EPO opposition work isn’t widely distributed across the European patent bar. It concentrates on practices with sector-specific technical depth, long-standing relationships with repeat challengers, and accumulated procedural experience at the Opposition Division and Board of Appeal. The firms at the top of these tables handle the proceedings that set the precedents and outcomes that matter commercially. The rest of the market handles the volume below them.
The Same Filing Count Means a Different Thing in Each Sector
Pharmaceutical opposition runs as a generics market-entry function across many drug families, structured around the EPO cost advantage over the U.S. district court. Tobacco opposition is a bilateral, oligopolistic contest in a single product category, in which a 2024 settlement resolved the existing litigation but left the next-generation patent pipeline fully active. Food opposition is a geographically concentrated nutrition-sector dynamic, with multiple companies having built in-house opposition capacity large enough to appear in the firm-level rankings. SEP opposition is a mixed ecosystem in which licensing vehicles, implementers, and established licensors all file for different reasons, and in which a meaningful portion of the activity is anonymized through consortium vehicles.
Treating opposition filings as a single aggregate misses the logic of each domain. The volume number, taken alone, tells you how busy the EPO opposition docket is. The sector-level data tells you why.
The Decision Problem This Data Creates
The four sectors in this dataset have distinct opposition structures, challenger profiles, and commercial logics. What they share is this: by the time an opposition appears on the EPO register, the commercial decision behind it was made weeks or months earlier. Teva doesn’t file 113 oppositions by reacting to individual grants. Nicoventures doesn’t sustain 60 filings in a single year without a systematic program identifying which competitor grants to target and when. Strawman Limited’s 210 filings don’t reflect spontaneous activity. They reflect instructed decisions that the public record was designed not to reveal.
For a company holding granted patents in any of these sectors, the register tells you a challenge exists. It doesn’t tell you which product the challenger is protecting space for, whether the named opponent is the real party in interest, or whether the same patent family is under parallel challenge at the USPTO or a national court. For a company assessing a competitor’s portfolio before a licensing negotiation or product launch, the register tells you which grants are active. It doesn’t tell you which of those grants are already under sustained opposition pressure from parties that haven’t publicly identified themselves.
That gap is where commercial decisions go wrong. A patent assumed to be a clean enforcement asset may have an opposition proceeding in its second year. A competitor grant assumed to be a licensing risk may already be under challenge by three parties, two of which are anonymized.
Licensing demand or a product launch decision that has already been made is useful for understanding the past. It doesn’t help with the fact that Nicoventures filed 60 EPO oppositions in a single year, that Elkington and Fife opened 235 pharmaceutical matters across the same five-year period, and that Strawman Limited’s instructing parties are making filing decisions on a rolling basis right now. The opposition programs this data reveals don’t pause between reports.
That’s the gap IP Verse is built to close. It tracks EPO opposition filings on a weekly update cycle, surfaces new proceedings by competitor, law firm, or technology area as they appear on the register, and connects EPO status to parallel UPC and PTAB activity in the same view. If Elkington and Fife files against a patent family in your area this month, or a new Strawman Limited filing appears against a grant relevant to your portfolio, it shows up when it happens rather than when a project is next scoped.
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