Asia Patent Alliance

Handling Expansion of Secret Prior Art in China


The expansion of secret prior art refers to cases shown in the diagram above, where Application A is filed first, and then Application B is filed (claiming an invention disclosed in the specification of Application A) before Application A is published. Please note that if the claims in Applications A and B are the same, they will have a relationship as prior and subsequent applications. If Application B is filed subsequent to publication of Application A, it will be rejected.

If Application B was filed after Application A was published, and Application B claims an invention disclosed in the specification of Application A, Application A is in a position of expanded prior art, and therefore Application B is refused. In other words, even if Application B has novelty and inventive step, it cannot be patented due to Application A, the expanded secret prior art.

In Japan and Korea, there is an exception to secret prior art when the applicant/inventor of Application A and B is the same. Thus, if the applicant of Applications A and B are the same, expanded secret prior art will not apply, even if the contents of Application B are included in the specification of Application A.

In China, a point to be aware of is that there is no exception to expanded secret prior art. According to Chinese patent law revisions in 2009, Application B will be rejected even if the applicant or inventors are the same due to the expanded prior art provisions.

  Applicant/Inventor is the Same
  Japan Yes No
Korea Yes No
China Yes Yes

Example: For a pharmaceutical invention, the claims in application A include common compound R and specific compounds R1 and R2, and while the specifications refer to experimental data of R1 and R2, the also mention that common compounds R3 and R4 may be used. (Common compountd R is a broader concept of R1, R2, R3, and R4). Meanwhile, the claims in Application B include specific compounds R3 and R4, and the specifications refer in detail to both related experimental data and pharmaceutical effects of R3 and R4. In order to obtain rights for R3 and R4 in China, either priority must be claimed or R3 and R4 must be deleted from Application A.