When inventiveness of the claimed invention is rejected during patent prosecution, it is a commonly-used method to prove technical effects by submitting supplemental experimental data under current patent practice.

Chapter 10 of Part II of the Guidelines for Examination prescribes: “The examiner shall review experimental data submitted after application date. The technical effect proved by the supplemental experimental data shall be one which is capable of being obtained from the disclosure of the patent application by a person skilled in the art.” However, the Guidelines does not specify what criteria the supplemental experimental data should satisfy.

Recently, one of the Top Ten Cases of Reexamination and Invalidation in 2017 issued by the Reexamination Board, Invalidation Case of ZL201110029600.7 “Pharmaceutical compositions comprising valsartan and NEP inhibitors” , gives a direction for the aforementioned criteria.

The involved patent is a pharmaceutical composition comprising valsartan and sacubitril. The invalidation petitioner believed that the closest prior art has disclosed a combination of NEP inhibitors and angiotensin II receptor antagonists for treatment of hypertension and congestive heart failure, and other evidence shows that sacubitril is a known NEP inhibitor, valsartan is a known angiotensin II receptor antagonist, and they both have an effect of lowering blood pressure. The patent claims that there is a synergistic effect in the pharmaceutical composition, but such effect cannot be confirmed, and therefore, claim 1 is not inventive.

During trial of the case, the patentee submitted a statement made by the inventor (hereinafter referred to ascounterevidence 1) to demonstrate that the pharmaceutical composition of valsartan and sacubitril has a synergistic effect of lowering mean arterial pressure in an animal model of hypertension. The counterevidence 1 was an experimental data submitted after the application date. Whether the technical effect demonstrated can be obtained from the disclosure of the patent application by a person skilled in the art should be judged comprehensively based on common technical knowledge in the art and the disclosure of the patent application.

Research on the mechanism of action of hypertension drugs in the prior art is relatively extensive, and the level of knowledge of a person skilled in the art is correspondingly relatively high. It is well known in the art that combination therapy is one of principles for selecting hypertension drugs, but by comprehensively understanding common knowledge evidence with respect to principles of combination therapy submitted by the petitioner, it can be found that the combination therapy having a synergistic effect is selective, rather than random. The choice of combinations of two drugs having different mechanisms of action that can produce the synergistic effects is not arbitrary. For example, in the case of combination therapy of different classes of antihypertensive drugs that can produce a synergistic effect, a central sympathetic inhibitor acting on central α2-receptor is combined with a diuretic and a vasodilator; and a sympatholytic agent is combined with a diuretic. The combination of drugs with different mechanisms of action is selected. Thus, that the combination therapy in the treatment of hypertension can achieve a synergistic effect is a general description of experience on the verified combination therapy having a synergistic effect, rather than a universal law obtained by induction and summarization. Therefore, a person skilled in the art cannot conclude that the synergistic effect can be obtained by different combinations of antihypertensive drugs on this basis.

In the case when those skilled in the art cannot predict that the composition consisting of valsartan and sacubitril has a synergistic effect of lowering blood pressure based on their knowledge, the disclosure of the description of the patent should be such that a person skilled in the art can confirm the existence of the synergistic effect. Otherwise, a person skilled in the art cannot obtain the technical effect from the original application document.

The description of the above patent discloses experimental methods such as animal models, administration methods, daily doses, test indicators and the like, and gives a simple conclusion that “The available results indicate an unexpected therapeutic effect of a combination according to the invention” , but does not disclose specific experimental data or results. The efficacy test usually includes methods, data and results, conclusions, etc., in which the experimental data and results play a critical role in demonstrating the effect ofthe drug, and the conclusions are based on the statistical analysis results of the experimental data. Under the premise that a person skilled in the art cannot predict a synergistic effect between valsartan and sacubitril, the description recording only the experimental methods and conclusions without experimental data and results does not enable a person skilled in the art to confirm that the combination of valsartan and sacubitril has the synergistic effect of lowering blood pressure. Therefore, the counterevidence 1 cannot be used to determine the technical effect of the patent.

What kind of technical effects are the technical effects that can be obtained from the disclosure of the patent application by a person skilled in the art? Firstly, the technical effects demonstrated in the patent application documents are undoubtedly the technical effects that can be obtained by a person skilled in the art. Thetechnical effects that are not demonstrated in the patent application documents can be divided into two categories, the first category includes the technical effects that can be expected by a person skilled in theart, and the second category includes the technical effects that are unexpected by a person skilled in theart. For the technical effects of the first category, even if the application documents do not provide experimental data, a person skilled in the art can obtain the effect by virtue of their knowledge and ability. For example, both valsartan and sacubitril are known compounds having an effect of lowering blood pressure. Even if the description does not provide experimental data, a person skilled in the art may know that the combination can achieve an effect of lowering blood pressure in the absence of counterevidence. However, as to the unexpected technical effects, if they are not demonstrated in the application documents, a person skilled in the art cannot obtain the effect from the disclosure of the patent application. For such unexpected technical effects, they usually cannot be proved by experimental data submitted after the application date.

	Author: JIN,Nican
	Patent Attorney

Mr. Jin joined Liu, Shen & Associates in 2005. He specializes in patent prosecution, re-examination, patent invalidation, and client counseling with a focus on battery, polymer, luminescent material, refrigerant, chemical Engineering, & nanomaterial.
Mr. Jin got his qualification as a patent attorney in 2006. He has participated in several patent lawsuits including patent infringement and patent invalidation. He has been leading patent invalidation and pre-litigation analysis in the firm.