For a patent application in the fields of chemistry, biology or medicine, it may be necessary to submit experimental data after the filing date, for example in order to avoid claims being rejected for not involving an inventive step. Regarding the acceptability of the after-filing experimental data, Chinese examiners previously adopted a very strict standard, i.e. it may be impossible to supplement any experimental result for the claimed technical solution. However, the situation has somewhat changed recently.

    According to the current version of the Guidelines for Patent Examination, as a general rule, experimental data submitted after the date of filing in order to meet the requirements of such as Article 22.3 (an inventive step) and Article 26.3 (sufficient disclosure) of Patent Law shall be examined by the examiner, and the technical effects proven by the experimental data submitted after the date of filing shall be those that are obtainable from the disclosure of the application by one skilled in the art. In other words, further experimental data can be submitted and taken into account, as long as the effects proven thereby are "obtainable" from the disclosure of the original description.

    However, the Guidelines for Patent Examination do not provide detailed explanations on "obtainable". In practice, it is often a problem to determine whether the effects proven by the after-filing experimental data are "obtainable" or not from the disclosure of the original description.

    In the following, two examples derived from the Guidelines for Patent Examination and one example in our patent practice are provided for better understanding of the term "obtainable".

    Example 1

    Claim 1 sets forth a compound A. The description discloses a preparation example of the compound A, the blood pressure reducing effect of the compound A and an experimental method for measuring the blood pressure reducing activity, but does not disclose any experimental result data.

    In order to prove the sufficient disclosure of the description, during the prosecution, the applicant submits the blood pressure reducing effect data of the compound A.

    For a person skilled in the pertinent technical field, according to the disclosure of the original application document, the blood pressure reducing effect of the compound A is already disclosed, and the technical effect to be proved by the after-filing experimental data can be obtained from the contents disclosed in the original patent application. Thus, the experiment data submitted after the filing date should be taken into account.

    Example 2

    Claim 1 sets forth a compound of general formula I. The description discloses the compound of general formula I and a preparation method therefor, the preparation examples of several specific compounds A, B, etc. falling within the range of general formula I, and also discloses the anti-tumor effects of the compound of general formula I, an experiment method for assaying anti-tumor activity, and the experimental result data. The experimental result data is disclosed as an IC50 value of the example compounds for tumor cells in a range of 10-100 nM.

    In order to prove that the claim involves an inventive step, during the prosecution, the applicant submits comparison experimental data, indicating that the IC50 value of compound A is 15nM, whereas the IC50 value of the compound in D1 is 87nM.

    For a person skilled in the pertinent technical field, according to the disclosure of the original application document, the compound A and the antitumor effect thereof are already disclosed, and the technical effects to be proved by the after-filing experimental data can be obtained from the contents disclosed in the original patent application. Thus, the experiment data submitted after the filing date should be taken into account.

    From the above examples 1 and 2 derived from the Guidelines for Patent Examination, we can try to find the common requirement with respect to "obtainable". From our understanding, if the original description describes the technical effects to be proved by the after-filing experimental data, and also provides experiment examples describing the assaying method and some preliminary or qualitative results to support the technical effects, we can assume that the technical effects proved by the after-filing experimental data are obtainable from the disclosure of the original application.

    Example 3

    This example is not derived from the Guidelines for Patent Examination, but obtained from an actual case in our recent practice. In this case, the examiner, in the decision of rejection, believed the experimental data submitted after the filing date should not be taken into account when evaluating inventiveness, but the panel, in the decision of reexamination, held a totally different opinion.

    Claim 1 sets forth a compound A. The description discloses that a conjugate of a compound A and an antibody can be used to treat tumors. The examples in the description demonstrate that the conjugate of a compound A with antibody 1 can reduce the tumor volume in mice. In order to prove that the claims involve an inventive step, during the prosecution, the applicant submitted further experiment data when responding to office action, in which the conjugate of compound A with herceptin (which is a type of antibody) has an improved anti-tumor activity compared with the conjugate of compound 93 of D1 with herceptin.

    In the decision of rejection, the examiner was of the opinion that the original description of the application does not disclose the experimental data of the activity of the conjugate of compound A with herceptin, and the curve of the change of tumor volume for the conjugate of compound A with herceptin in the after-filing experimental data is inconsistent with the curve for the conjugate of compound A with antibody 1 disclosed in the original application. As such, the technical effects proved by the after-filing experimental data are not obtainable from the disclosure of the original application, and should not be taken into account when evaluating inventiveness.

    The panel responsible for the reexamination of the case had an opposite opinion on the after-filing experimental data. In the reexamination decision, the panel believed:

    Both herceptin and antibody 1 in the present application belong to an Her-2 antibody, and both bind to an Her-2 receptor. The performances and effects of the two antibodies are very similar. Although the curve of the change of tumor volume for the conjugate of compound A with herceptin in the after-filing experimental data is not completely consistent with the curve for the conjugate of compound A with antibody 1 in the original application, a similar trend is followed. Since the experimental data for the conjugate of the compound A and antibody 1 (with a similar performance with herceptin) have been provided in the original description, the technical effects of compound A of the present invention proved by the after-filing experimental data are those that are obtainable by a person skilled in the art from the disclosure of the original description, and the improved effects of the present invention proved thereby with respect to D1 should be taken into consideration when determining the inventive step.

    Although there is no detailed explanation in the Guidelines for Patent Examination on how to precisely understand "obtainable", we can make reference to the two examples given above and the real cases accumulated in our practice in an attempt to find a proper understanding of the requirements with respect to "obtainable".