We are a leading force in EPO oppositions

When it comes to opposing or defending European patents, experience matters. A look at our track record across both offensive and defensive oppositions over the last 12 years highlights not only the depth of our experience in handling EPO opposition proceedings but also our track record of obtaining successful outcomes for our clients in these high stakes cases, which compare favourably with other leading firms.

A Trusted Partner for Defending High Value Patents

We have extensive experience in defending EP patents under opposition. Over the past 12 years, Mewburn Ellis ranks:

• 6th for the number of defensive oppositions across all technical fields
• 5th in the pharmaceutical field
• 2nd in the biotechnology field 

Number of patents

These rankings reflect the trust placed in us by industry leading innovators who rely on robust patent portfolios to safeguard their R&D investment. Our team combines technical excellence with a strategic mindset, ensuring that every defence is shaped by a full understanding of the commercial context.

The data show that our success rates compare favourably with the other top 5 patentee representatives in both biotechnology and pharmaceuticals – sectors where the stakes can often be particularly high. 

We are experts in opposing European patents

Mewburn Ellis ranks among the top 20 firms for the number of offensive patent oppositions handled across all technical fields, and in the top 3 firms for offensive oppositions in the biotechnology sector.

Our results underscore the strength of our approach. Only 9.6% of patents we have opposed have been maintained as granted, better than any of the top 10 most active opponent representatives. This exceptional success rate reflects our ability to identify the key vulnerabilities in granted claims and deliver outcomes that matter for our clients’ commercial objectives.

Expertise before the EPO Boards of Appeal

Our figures are even more impressive when considering offensive opposition cases that included an appeal stage, with Mewburn Ellis achieving a higher percentage of patents revoked, and a lower percentage of patents maintained as granted than any of the top 10 most active opponent representatives following an appeal stage.

Why Clients Choose Mewburn Ellis for Opposition Work

Clients who turn to us for opposition matters value:

• Outstanding success rates, both attacking and defending.

• Deep scientific and technical expertise, covering every major technology sector.

• Strategic insight, grounded in decades of experience at the EPO.

• A collaborative approach, ensuring arguments are aligned with wider commercial goals.

• A reputation for excellence, supported by strong, independently verified statistics.

Whether a client needs to clear the way for product launch, challenge a competitor’s position or defend a cornerstone patent, they know they can rely on our team’s precision, rigour and exceptional advocacy skills.

Your Partner for High Stakes EPO Opposition Cases

European patent oppositions require not only scientific depth and procedural mastery but also the ability to anticipate developments and craft strategies that stand up under scrutiny. Mewburn Ellis brings all of this together – and our long term statistics prove the strength of our approach.

If you’re looking for a partner with a demonstrated record of success in both offensive and defensive opposition work, our team is ready to help.


Note: All data taken from IP Quants.