Functional, use and specific-purpose features in product claims under Vietnam’s patent examination guidelines

The Patent examination guideline of Vietnam provides specific guidance on the assessment of inventions containing features relating to the function, use, or specific purpose of a product, particularly in the context of assessing novelty. This guidance is particularly relevant to inventions in the pharmaceutical and biotechnology fields, where claims frequently define products by reference to their therapeutic effects, biological function, intended use, or specific purpose.

Under these provisions, where a product is defined by functional, use-related, or purpose-related features, the claimed subject matter normally remains the product itself. Common expressions include “for use”, “for treating”, “for manufacturing”, “when used”, “used as”, “having activity”, “having an effect”, and “having a function”.

For such claims, in addition to examining the essential technical features that characterize the product (structure, configuration, components, etc.), the examiner will consider whether the functional features, uses, or specific purposes recited in the claim imply that the claimed product possesses any specific structure, configuration, or components. In this regard, the information disclosed in the description plays an important role.

For pharmaceutical and biotechnology inventions, where the functional feature, use, or specific purpose does not imply any structure, configuration, or component, that feature is not considered when assessing novelty. Conversely, where the feature implies a particular structure, configuration, or component, it is considered in the novelty assessment. In the case of claims directed to compounds, functional features, uses, or specific purposes are not considered for novelty because they do not imply the structure of the compound itself.

For example, with a claim “compound X is effective in treating cancer”, the claimed subject matter is understood to be compound X itself. The feature “effective in treating cancer” does not imply any structural feature and is therefore not considered when assessing novelty. Any cited document, which disclosed the compound X, shall destroy the novelty of the claim. This example illustrates that a known compound cannot generally acquire novelty merely by being characterized by a particular therapeutic function or use.

On the other hand, with a claim “preparation containing galactose and excipients for parenteral administration”, the feature “for parenteral administration” implies technical requirements concerning the components of the preparation, particularly the suitability of the excipients for injection. In case of cited documents only disclosed a preparation containing galactose with the solid excipients such as talc, starch, and microcrystalline cellulose, which are commonly used in tablet formulations but are unsuitable for parenteral administration, the claim shall be considered as novel. Accordingly, the feature “for parenteral administration” has technical significance and must be considered in assessing novelty. 

These examples demonstrate that the inclusion of a functional, use-related, or specific-purpose feature does not automatically confer novelty on a product. The key question is whether the feature implies a technical difference in the product itself.

In pharmaceutical and biotechnology patent examination, this distinction is particularly important for claims involving therapeutic effects, biological functions, routes of administration, or specific applications. A new therapeutic effect shall not bring the novelty for a well-known compound or composition. Only purpose or use that necessarily requires a different composition, structure, or component may distinguish the claimed product from prior art.