With the implementation of the America Invents Act and the United States moving to a first-to-file regime, there is greater time pressure to file patent applications than ever before. When patent protection in ex-US jurisdictions is also of interest, filing strategy can be complicated by increasingly short, if not, nonexistent grace periods. The use of post-filing data supporting patentability can ameliorate some of that stress, but its admissibility is dependent on the filing jurisdiction and can be treated very differently depending on its use.

United States

Post-filing evidence is routinely used in applications to support prophetic examples often times in rebutting a rejection based of lack of enablement. This evidence is particularly effective when the prophetic examples describe the manner and process of making and using an embodiment of the invention, and the post-filing data is used to demonstrate what was expected. This scenario often comes into play in the life sciences where compounds may have been created, but in vivo testing may not have been performed. In cases such as this, the USPTO allows for submission of post-filing evidence that supports the prophetic disclosure.

But what about situations where post-filing data is needed to rebut an assertion of obviousness? In many cases, a US Examiner will require an affidavit or declaration containing evidence of criticality or unexpected results be submitted for consideration. To have probative value in the determination of nonobviousness, there must be a sufficient factual and legal connection between the objective evidence and the claimed invention.


China has a relatively strict approach to the determination of sufficiency of disclosure, especially when compared to the approach taken in other jurisdictions, such as the US and Europe. Although the patent examination guidelines were loosened in 2017, the determination of sufficiency of the disclosure, is still performed based upon the contents of the specification as originally filed. The Amended Guidelines make clear that, “The Examiner shall examine supplementary experimental data submitted after the date of filing. The technical effect to be demonstrated by the supplementary experimental data should be (an effect) that can be arrived at by a person skilled in the art from the contents disclosed in the patent application.” Thus, post-filing experimental data demonstrating a technical effect, should not be rejected outright, but may be considered as long as the technical effect can be understood by a person skilled in the art from the application as originally filed.

Since the China National Intellectual Property Administration (CNIPA) usually requests that technical effects to be proved by supplementary data be directed to a technical effect capable of being known by a person skilled in the art as of the filing date, the SIPO requires that there is explicit disclosure in the original data of a relevant technical effect. Absent that original data, the CNIPA generally will not allow supplementary experimental data be used to prove inventive step, even if the data is comparative relative to the prior art.


The Examination Guidelines for Patent and Utility Model in Japan requires that supplementary experimental results are not a substitute for a “Detailed Description of the Invention” in a patent application. Similar to China however, as long as the relevant effects are disclosed in the original patent specification, or can be speculated by a person skilled in the art from the specification or drawings, post-filing data demonstrating technical effects will be taken into consideration during prosecution.

The High Court in Japan loosened the requirements for when supplemental data is allowable for cases related to inventiveness in 2010. The Court held that since an applicant is not able to know which cited prior art will be compared with the claimed invention, it is not fair to the applicant if they have no opportunity to objectively verify any technical effects based on comparative data. Thus, the Court held that even in cases where an application does not explicitly disclose remarkable technical effects but they can be derived from the specification, it is allowable to take supplemental data into account in the context of the determination of inventive step.

This article appeared in the September 2019 issue of Global Patent Prosecution.