Patent Drafting and Patent Prosecution

Patent Drafting and Prosecution: Securing Strong and Enforceable Patent Rights

A patent is only as strong as the application on which it is based and the strategy followed during prosecution and eventual oppositions and revocation procedures.

Patent drafting and prosecution are decisive stages that determine whether meaningful patent protection is obtained, how broad that protection is, whether it can ultimately be enforced against competitors, and whether it can stand an opposition or revocation procedure.

Why Patent Drafting Quality Is Critical

Once a patent application is filed, its content cannot be freely changed.

The description, claims, and drawings define what can be protected and what may be irreversibly lost. Poor drafting may result in claims that are too narrow to be commercially relevant, an inability to amend during examination or opposition, or a permanent loss of rights that cannot be recovered later.

In practice, drafting errors are often irreversible.

The Importance of a Detail-Rich Patent Specification

A strong patent application relies on a detail-rich and well-structured specification.

The description should disclose multiple technical features, alternatives, and embodiments, as well as parameters, variants, and technical effects. This level of detail is essential to allow amendments during prosecution without adding subject matter.

Without sufficient disclosure from the outset, even valuable inventions may fail to obtain effective or enforceable patent protection.

Drafting Claims That Are Broad but Defensible

Patent claims must strike a careful balance between commercial breadth and legal defensibility.

Claims should be broad enough to cover relevant commercial embodiments, while remaining novel and inventive over the prior art. Overly narrow claims may be easy to grant but provide little value. Overly broad claims risk refusal or later invalidation.

Achieving this balance requires a thorough understanding of the invention, what the value for the company is, how the IP asset is to be used by the company throughout its life, awareness of relevant prior art, and experience with how patent offices assess novelty and inventive step (non-obviousness).

Granularity and Amendments During Prosecution

During patent prosecution, objections from patent offices are the rule rather than the exception.

Amendments are often required to overcome objections. However, amendments are only allowed if they are clearly and unambiguously supported by the original application.

A granular disclosure of features and embodiments allows claims to be refined during prosecution while preserving scope and validity. Without such granularity, important fallback positions for the grant of a patent may be unavailable, which may cause the refusal of the patent application or the revocation of the patent.

Local Patent Practice and Case Law

Patent law is international, but patent practice is local.

Effective patent drafting and prosecution strategies must therefore be adapted to local practice and relevant case law in each jurisdiction. This applies irrespective of whether the patent applications are drafted and filed at national or regional level, or when a Patent Cooperation Treaty (PCT) international application level, which laters on enters national or regional phases like the European regional phase.

Europe

At the European Patent Office (EPO) and the national patent offices covered by the EPO, strict rules apply, particularly with respect to added matter and claim amendments. Inventive step is typically assessed using the structured problem-solution approach, and examination practice is rigorous.

The existing and always-evolving Case Law of the Boards of Appeal change how the law is applied to each patent and patent application regarding interpretation of the claims, amendments that may or may not be made, or whether a claimed invention solves a technical problem.

A granted European patent, which is potentially converted into a Unitary Patent and/or a bundle of national patent rights through validation of the European patent, like in Spain, may suffer the consequences of a patent application drafted and/or prosecuted without too much care and detail.

United States of America

US patent practice differs considerably, especially regarding claim interpretation, amendments, continuation strategies, and very strict legal effects of statements made during prosecution.

Inventive step, or non-obviousness, is assessed considering the teachings of the prior art references as a whole. The combination of more than two documents in a non-obviousness rejection is fairly more common than in other jurisdictions.

Whereas, for example, inventions relating to methods practised on the human or animal bodies cannot be protected in Europe, such methods may be protected in the US. The knowledge of such particularities allows broadening the scope of protection as much as possible to what the local practice allows.

Coordinating Global Patent Drafting and Prosecution Strategies

For international patent families, a lack of coordination between jurisdictions can significantly undermine protection.

Amendments or arguments made in one jurisdiction may limit claim scope or create inconsistencies elsewhere. In some cases, they may even affect enforceability in other countries.

A coordinated global strategy helps ensure that claim scope remains aligned, amendments are made consciously, and long-term enforcement risks are taken into account from the outset. And when particular jurisdictions allow or forbid protecting certain embodiments, the global strategy is to aim at maximizing the patent protection in the particular jurisdictions even if the claim scope does not remain fully aligned among jurisdictions.

Avoiding Prosecution History Estoppel

Statements and amendments made during prosecution can later limit the scope of protection.

In certain jurisdictions, such as the United States, Germany, the United Kingdom, to name a few, prosecution history estoppel may prevent reliance on equivalents if claims were narrowed to obtain grant.

A wise prosecution strategy seeks to minimise unnecessary claim narrowing, avoid restrictive admissions, and preserve flexibility for future enforcement.