Obtaining multiple patents with overlapping or partially overlapping claim scopes is a common strategy to ensure comprehensive and robust legal protection for an invention. This approach can strengthen protection against infringement, offer flexibility in licensing, and preserve protection if one patent is invalidated. It is particularly important in biotechnology, where inventions often evolve during patent prosecution and new technologies frequently encompass many related inventions.
To achieve this, applicants must navigate the issue of double patenting – the grant of multiple patents covering the same subject matter which is prohibited in most jurisdictions. Here, we aim to provide an overview of how the major pharmaceutical and biotechnology jurisdictions handle double patenting, highlighting differences in allowable overlap in the scope of protection (if any), and the strategic considerations for building resilient global patent portfolios.
What is double patenting
To prevent the unjustified extension of patent terms and/or multiple enforcement actions based on the same invention, nearly all jurisdictions prohibit same-invention double patenting – that is, the grant of two patents with identical claim scopes to the same applicant.
Given these restrictions, how is it possible to secure two patents with overlapping claim scope? The most common and structured approach is to file divisional patent applications.
Divisional patent applications
A divisional patent application is filed from an earlier pending application (the “parent” application) to pursue inventions disclosed in the parent application. Divisional applications are most commonly filed to address a lack of unity objection; however voluntary divisional applications are allowed in most jurisdictions and provide a very useful tool for securing additional protection for a given innovation.
The divisional applications generally retain the priority date of the parent application, meaning that the parent application cannot be cited as prior art in the examination of the divisional application. Once granted, the divisional patent is an independent right which can be enforced and licenced separately from the parent patent.
Double patenting in different jurisdictions
While all jurisdictions prohibit seeking protection for identical claim scope in a divisional application, in most countries, some level of overlap in the scope of protection is permitted. This creates an exciting opportunity for companies to strengthen the overall coverage of their protection for a given technology, making it very difficult for competitors or third parties to work around their invention.
For ease of comparison, we divided the countries with significant pharmaceutical and biotechnology patent filings into three broad categories relating to how strictly double patenting is assessed during prosecution.
| Strict double patenting provisions |
Jurisdictions which do not typically permit any overlap in the scope of protection between the parent and divisional case |
India, Canada |
| Moderate double patenting provisions |
Jurisdictions where some level of overlap in the scope of protection between the parent and divisional case is allowed |
UK, Japan, China, Israel, Singapore, South Korea
|
| Lenient double patenting provisions |
Jurisdictions where inventions of fully overlapping scope can be protected in a divisional application |
Europe, Australia, New Zealand, U.S. |
Strict double patenting provisions
India and Canada take one of the strictest approaches to double patenting. In Canada, a divisional application should only be filed if a unity objection was raised during prosecution of the parent application. Similarly, in India, the subject matter pursued in a divisional application must be related to a different inventive concept than that of the parent application.
This means that claims of overlapping scope cannot be pursued in those jurisdictions, highlighting the importance of securing protection for all embodiments of interest in one (parent) patent application.
Moderate double patenting provisions
Jurisdictions including the UK, Japan, China, Singapore, Israel, and South Korea prohibit same invention-type double patenting but allow some level of overlap in the scope of the claims between the parent and divisional case.
For example, divisional applications can be pursued with claims of partially overlapping scopes, such as distinct aspects of the same disclosure, or different categories of claims, provided that the resulting claims are not substantially identical to those of the parent patent. In practice, this means that the dependent claims of those divisional applications have to be adjusted to ensure they do not lead to obtaining an identical protection to that of the parent case.
Lenient double patenting provisions
Some jurisdictions take a more lenient approach to double patenting.
Europe allows not only partially overlapping claims, but also claims that fully overlap. For example, the parent claims may be directed to a specific compound that is in clinical development, whereas the divisional claims may encompass a broader genus of chemical structures, which encompass the specific compound of interest. This enables the creation of a portfolio of patents for a given technology with varying scope and enforceability, thereby mitigating the risk that all patents for that technology will be invalidated.
The same strategy can be applied in, for example, the U.S., Australia, and New Zealand. In the U.S., filing of a terminal disclaimer may be required to overcome an obviousness-type double patenting rejection, potentially reducing the number of Patent Term Adjustment (PTA) days the application might have accrued over the parent case.
Strategic considerations
So, what should you keep in mind when creating a strong patent portfolio?
- Plan claim scope early
Consider the strategy for the claims as early as possible. Filing multiple divisional applications is likely to be costly. Thus, identify jurisdictions of most commercial importance and plan the strategy accordingly.
- Account for jurisdiction-specific double patenting rules
Different jurisdictions have different tolerance levels for overlapping claims, so it is important to tailor your strategy to the jurisdiction’s requirements.
- Consider patent term and family coordination
Consider how filing strategy affects patent term (e.g. terminal disclaimers in the U.S.) and enforceability across the family. Coordinate filings to avoid unintended term loss or risk of invalidity.
At Boult we bring extensive expertise in strategic portfolio planning to comprehensively cover your innovation. We understand the unique challenges and nuances required to secure meaningful and enforceable patent protection in different jurisdictions around the world. Reach out to discuss your IP strategy today.
