New amendments to claims in China’s patent invalidation procedure are best exemplified by looking at a recent pharmaceutical case in the country.

In China, if the validity of a patent is challenged in invalidation procedures, the patentee may amend the claims to make the patent immune to attack. In consideration of the public’s reliance interest, the Guidelines for Examination enacted by the State Intellectual Property Office (SIPO) sets forth more strict requirements for amendments in invalidation procedures than those in substantive examination stage.

In principle, any amendment that goes beyond the scope of the claims as granted will be rejected. On the other hand, whether the patent will be maintained as valid or declared invalid may depend on whether the amendment is accepted by the Patent Reexamination Board (PRB), the sole government organisation responsible for the examination of request for patent invalidation.

In an invalidation case concerning patent No. 03150996.7 (“the patent in issue”), the PRB rejected the amendments to the claims made by the patentee in the invalidation procedure and made a decision declaring the patent right invalid with respect to all claims. Concerning the decision, a series of administrative litigation procedures were initiated. The first instance judgment agreed with the opinion of the PRB of rejecting the amendments, whereas the second instance judgment ruled that the PRB shall accept the amendment. The PRB was not satisfied with the second instance judgment, and requested rehearing before the Supreme People’s Court (SPC).

The SPC refused the PRB’s request for rehearing. The decision delivered by the SPC found that “the PRB took the strict side in interpreting the provisions of the Guidelines for Examination concerning amendment in invalidation procedures”, and maintains the second instance judgment.

Meanwhile, the SPC comments that when determining whether an amendment made during invalidation proceedings should be allowed, one shall consider the original intention of legislation as well as the principle of fairness and reasonableness.

In recent years, patent applicants and patent professionals have been complaining that the examination standards adopted by the SIPO on amendment of applications/ patents are “rigid” and “too rigorous”. The SPC’s decision on this case and comments contained therein may be regarded as echoing the complaints and setting forth a directive for the examination of the SIPO as regards the concerned issues.

Introduction of the case

Claim 1 of the patent in issue reads as follows: “A compound preparation, characterized in that the preparation is a pharmaceutical composition composed of amlodipine or its physiologically acceptable salt and irbesartan as active components in a weight ratio of 1:10-30.”

During the invalidation procedure, the patentee submitted an amendment of changing the claimed numerical range of 1:10-30 (the corresponding range in the original application is 1:10-50) to 1:30. The PRB rejected the amendment on the ground that the amended claim presented “a specific value selected from a continuous numerical range, whereas the original claims and description neither have explicitly recited the value nor have taught making such selection within the range”.

In the administrative litigation stage, dispute between the involved parties was focused on the following issues:

  1. Whether this manner of amendment should be allowed in the invalidation procedure.
  2. Whether the amendment goes beyond the scope of the original description and claims.

As to the first issue, the SPC made the following comments in its decision:

“Although the original claim 1, in terms of the numerical range of 1:10-30, is not a claim typically consisting of parallel technical solutions, it is fair to allow the patentee to make the amendment of 1:30 since the ratio is explicitly recited in the original description and the amendment can make the patent in issue more definite in its protection scope… Moreover, since the ratio of 1:30 is described as a preferred embodiment of the invention in the original description, the amendment neither goes beyond the scope of the original description and claims, nor beyond the protection scope of the patent as granted. Thus, allowing the amendment rather than not is more in compliance with the intention of relevant legal provisions concerning amendment of a patent during invalidation proceedings. In addition, it is true that the amendment is not of a manner explicitly prescribed in the Guidelines for Examination as being allowable, but it is nevertheless not prohibited.”

As to the second issue, the SPC is of the following opinions: “The description has explicitly disclosed the combination of 1 mg/kg of amlodipine and 30 mg/kg irbesartan as the most preferred ratio. Moreover, the working examples of tablet preparation have illustrated a combination in which amlodipine and irbesartan are in weight ratio of 1:30. Thus, the description has disclosed the ratio of 1:30.”

Discussion

It is prescribed in the Guidelines for Examination that one of the principles of amendment in the invalidation procedure is that “the amendment shall not go beyond the scope of disclosure contained in the initial description and claims”. This principle is literally the same as that of Article 33 of the Patent Law, which says that “[A]n applicant may amend his or its application for a patent, but the amendment to the application of a patent for invention or utility model may not go beyond the scope of the disclosure contained in the initial description and claims”. Thus, although this case is about amendment in invalidation procedures, the decision made by the SPC can also give guidance on the interpretation of Article 33 of the Patent Law, which concerns amendment during prosecution of a patent.

The reason for such prescription is that Chinese patent system adopts first-to-file principle; if the Patent Law allows amendment going beyond the scope of the originally filed application, it will contradict first-to-file principle, and it is also unfair to other applicants. The prescriptions concerning amendment in the invalidation stage ensure the invariability of the protection scope of patent claims that has been announced to the public. They are aimed at balancing between the benefit of the public and that of the patentee, while preventing a proprietor from enjoying an exclusive right to an invention which he had not made at the filing date. In this case, the SPC is of the opinion that, as long as the benefit of the public is not impaired, an amendment should not be refused only due to minor defects that are left by the initial drafter of the patent specification.

Interpretations

Concerning amendment during invalidation proceedings, the Guidelines for Examination prescribes that “the specific manners of amendment are generally limited to deletion of a claim, combination of claims, and deletion of a technical solution”. As to how the term “generally” should be interpreted, there have been diverted opinions.

In this case, the SPC ruled in its decision that “it is true that the Guidelines for Examination prescribes that the specific manners of amendment are generally limited to the three (listed) manners; however, it does not rule out other manners of amendment.”

In expounding why the amendment in this case should be allowed, the SPC noted that the claim contains only one variable, that is, the ratio of 1:30, and that the amendment makes the patent more definite in protection scope, although this may not be the case if the claim otherwise contains several variables. Moreover, since the ratio of 1:30 is described as a preferred embodiment of the invention in the original description, the amendment neither goes beyond the scope of the original description and claims, nor beyond the protection scope of the patent as granted.

In view of the above, it can be seen that in the SPC’s opinion, the manner of amendment in the invalidation stage is not limited to those specifically listed. When determining whether an amendment is allowable, one must inquire into whether the substance of the amendment falls within the circumstance which is prohibited according to the original intention of the provisions of the Patent Law concerning amendment. The amendment is not allowed only if the result of the inquiry is positive and should not be refused only because of the manner of amendment.

In fact, it seems that the SPC urges against giving too much weight on the manner of amendment and calls for looking more at the substance of the amendment, taking into account of balancing between the public and the patentee.

Disclosure

Another argument that the PRB had is that the ratio of 1:30 is not disclosed in the original description and claims. They found that the ratio has neither been disclosed in the original description and claims, nor can be generalized from the only specific example using 1 mg/kg of amlodipine and 30 mg/kg of irbesartan disclosed in the description. They considered the example as only representing a specific dosage, rather than a general ratio.

The SPC disagreed and commented that the specific combination of 1mg/kg of amlodipine and 30 mg/kg irbesartan disclosed in the original description represents the claimed combination of amlodipine and irbesartan in the ratio of 1:30. The SPC found that the description has disclosed a biological test on rats with said combination and the description recited the applicable dosage as being in the ranges of 2-10mg for amlodipine and 50-300 mg for irbesartan. Therefore, if the recommended combination of 1mg: 30mg is construed as only representing a specific dosage rather than a ratio in general, such combination is not within the above applicable dosage ranges. Apparently, this is an unreasonable construction.

It can be seen that the SPC sticks to the position that the content of a patent application shall be understood from the perspective of those skilled in the art; thus, the disclosure is not limited to the literal words of the original application, but also comprises the content which can be necessarily deduced by those skilled in the art. The patent in issue relates to a pharmaceutical preparation. In this technical field, an essential step for developing a preparation is to find a suitable ratio between the active components which produces good pharmaceutical effect, such as synergistic effect. Such ratio is generally obtained in an animal model, and then specific dosage of the preparation usable for human can be determined. Obviously, the SPC has taken into consideration the above common knowledge in the art when determining the original disclosure of the patent.

Future impact

In this case, the SPC provides clear guidelines for determining whether an amendment in the invalidation procedure may be allowed. In particular, the SPC confirms the legal standards in determining whether an amendment may be allowed, that is, the amendment must not go beyond the scope of the original application, nor beyond the protection scope of the patent as granted. In practice, the amendment must not violate the principles of ensuring the invariability of the protection scope of the patent that has announced to the public at the time of patent grant and balancing between the public and the patentee. The SPC also affirms the correct approach of determining the original disclosure of a patent from the perspective of those skilled in the art. Under this approach, not only the literal words but also the content which can be necessarily deduced in light of common knowledge in the art shall be considered.