Jiancheng Jiang of Peksung Intellectual Property describes recent case law relating to second-use inventions, and asks whether the judgments will break through China's reliance on codified laws

In China, as in other countries around the world, methods for the diagnosis and treatment of diseases may not be granted a patent right (article 25.1 of the Chinese Patent Law). Under the examination practice of the State Intellectual Property Office (SIPO), it is possible to use the so-called Swiss-type claim format for seeking protection for a second medical use invention of a substance so as to avoid the application of article 25.1. SIPO's Guidelines for Examination explicitly provides that the claim of a second medical-use invention can be drafted as "use of compound X for preparing a medicament for the treatment of disease Y". Such a claim type is considered as a use claim as it is a method for preparing a medicament (part II, chapter 10, section 4.5.2 of the Guidelines for Examination 2010), and so does not fall within the category of methods for the diagnosis and treatment of diseases. Put another way, such inventions, in terms of their subject matter, can get patent protection under the Chinese practice.

It is generally believed that the above-mentioned provision in the Guidelines for Examination is made by drawing references from the practice of the European Patent Office (EPO). Even after the EPO terminated the use of Swisstype claims through case law (EPO Enlarged Board of Appeal decision G02/08), SIPO continues to use it. Nevertheless, SIPO examination practice in this area is different from that of the EPO.

In practice, some medical use inventions contribute to prior art, mainly in discovering a new dosing regimen of a medicament (such as a new dosage amount, or dosing interval) rather than in finding out new indications. These inventions may be valuable to companies who seek innovations in the use of an existing pharmaceutical product. As to the patent applications of such inventions, the EPO explicitly admits the patentability of the second medical use claim defined by dosing regimens (EPO Enlarged Board of Appeal decision G02/08). Nevertheless, SIPO would examine whether or not the features related to using the medicament, such as the mode, route, usage amount and interval of administration, have a limiting effect on the preparation procedure of a medicament; a distinguishing feature over the prior art that is merely embodied in the course of administering the medicament does not make the claim novel (see part II, chapter 10, section 5.4 of the Guidelines for Examination). According to this examination standard, if the distinguishing features of a Swiss-type claim are merely embodied in the course of administration but cannot define the procedure of preparation of a medicament, they may not be considered in the assessment of novelty and inventiveness of the claimed invention. This examination standard prevents most inventions in China relating to a new dosing regimen from being protected.

On this issue, however, the judicial authorities of China have made judgments that are seemingly inconsistent with the examination standard.

Chinese patent ZL94194471.9

Chinese patent ZL94194471.9 relates to a second medical use invention, of which the granted claim 1 reads as:

1 The use of 17 -(N-tert-butylcarbamoyl)-4- aza-5 -androst-1-ene-3-one for the preparation of a medicament adapted for oral administration useful for the treatment of androgenic alopecia in a person and wherein said medicament comprises about 0.05-3.0 mg dosage amount of 17 -(N-tert-butylcarbamoyl)- 4-aza-5 -androst-1-ene-3-one.

In the invalidation proceedings of the patent, the Patent Reexamination Board (PRB) presented the following opinions:

This patent differs from the prior art in that: (1) the dosage amount of the medicament defined in this patent is 0.05 to 3.0 mg; and (2) this patent defines that the medicament is orally administered. Nevertheless, distinguishing feature (1) has no limiting effect on the claim, and thus shall be deemed to be nonexistent in the assessment of novelty and inventiveness; and distinguishing feature (2), as the PRB admitted, has limiting effect on the medicament product to some extent, and thus could confer novelty to claim 1.

In its invalidation decision, the PRB detailed the grounds of these findings. As to feature (1) (0.05-0.3 mg dosage amount), the PRB deemed that it has no limiting effect on the method for preparing the medicament. The PRB held that, since the use of a substance in the preparation of a medicament substantially equates to a method for preparing the medicament, only the features of raw materials, preparation steps and conditions, the form and components of the medicament product, have a direct limiting effect on the use. Administration is a step carried out after the medicament is prepared. Therefore, the preparation and administration of a medicament are two different steps, and do not coincide in terms of time domain. In order to achieve the above-mentioned dosage amount, the medicament could be administered to a patient with a smaller dosage amount more times or with a larger dosage amount fewer times. This is common knowledge in the art. The intake dosage of a medicament would have no limiting effect on the raw materials, preparation method or indications of the medicament.

As to feature (2), the PRB deemed that although the feature also concerns the method of using the medicament, it generally implies some product features of the medicament, for example, oral administration requires the auxiliaries to be suitable for oral intake, and thereby has a limiting effect on the selection of auxiliaries. Therefore, the feature does have a limiting effect on the medicament product to some extent.

Based on the above findings, the PRB considered merely feature (2) in the assessment of inventiveness of this patent, and finally made the decision that the patent has no inventiveness.

Appeal to the Higher Court

The patentee appealed to Beijing Number 1 Intermediate People's Court. The court upheld the decision of the PRB. The patentee further appealed to Beijing Higher People's Court. The Higher Court finally judged that the first instance judgment would be upheld. Noticeably, in the final judgment, an analysis different 4 to that of the PRB and the court of the first instance was made.

Specifically, the Higher Court did not agree on the findings of the PRB in terms of the limiting effect of feature (1). In particular, the Higher Court held that a medical use invention is substantively an invention of a method for administering a medicament. The technical features concerning administration of a medicament (so-called dosing characteristics, such as dosage form and amount used), should be read into the claim. In addition, the preparation of a medicament includes all the procedures before packaging for sale, and of course includes the dosing characteristics. Under the circumstances that the patentee improves the dosage form, amount, and the like, disregarding the dosing characteristics is unfavourable to the development of the pharmaceutical industry and to meeting people's need for healthcare, and does not conform to the legislative purpose of the Patent Law (Beijing Higher People's Court Administrative Judgment (2008) Gaoxingzhongzi 378).

A rare decision

This judgment of the Higher Court attracted attention from the public. In China, cases to which the court declines to apply the provisions of the Guidelines for Examination are rare. The Higher Court seemed to deem that the dosing characteristics should be treated as a part of the procedure in the preparation of a medicament (that is, having limiting effect on a medical use claim), and thus may be considered in the assessment of novelty and inventiveness. The judgment offered a glimmer of hope to companies active in this field. The judgment may have cleared the way for seeking protection for such inventions. Nevertheless, things are not so simple. As is known, Chinese practice does not necessarily follow precedent. A court judgment is binding only on the case it deals with, and not universally. In fact, after the Higher Court's judgment, SIPO did not adopt the opinions of the Higher Court, but followed the past standard when they amended the Guidelines for Examination in 2010 to match the Patent Law, as effective from October 1 2009.

Recently, a decision made by the Supreme People's Court on Patent 99812498.2 seems to put an end to the issue.

Clarification by the Supreme Court

The case was initiated before the PRB as a patent invalidation case. Claim 1 of the patent as granted reads as:

1 Use of daptomycin for the manufacture of a medicament for treating a bacterial infection in a patient in need thereof while not resulting in skeletal muscle toxicity, wherein a dose for said use is 3 to 75 mg/kg of daptomycin wherein said dose is administered repeatedly at a dose interval of once every 24 hours or 48 hours.

In the invalidation proceedings, the PRB deemed that a prior art document discloses the same medical use of daptomycin as that claimed in the present patent, with merely the dose and dose interval being different. It is well known to those skilled in the art that the features of dosage amount, repeated administration and dose interval are information to be selected and determined according to patients by doctors in the treatment process, and so constitute information involved in administration process and have nothing to do with process of manufacturing the medicament. Therefore, dosage amount, repeated administration and dose interval have no limiting effect on the medicament per se, and cannot distinguish the medical use of claim 1 from that of the prior art. In other words, the PRB deemed that these features are distinguishing features only embodied in the administration process, and so cannot bring novelty to the use of the patent. After the case was appealed to the court, the Intermediate Court as the first instance court, and the Higher Court as the second instance court, both upheld the decision of the PRB. The patentee then requested retrial before the Supreme People's Court.

The Supreme Court, in its retrial ruling, stated that Swiss-type claims involving second medical use are of process type. Such claims exclude other other manufacturers from manufacturing the same product with the same use. In this way, the technical features of such claims should still be analysed from the process claim view. Usually, it is the raw materials, preparation steps and technological conditions, the form and components of a pharmaceutical product, and the equipment used, that have limiting effect on the claims. As to the features involving merely administering a medicament (such as the dosage amount and dose interval), if they have no direct relation with the preparation of the medicament, they are actually a particular method for applying the medicament to humans after implementing the method for the preparation and obtaining the medicament. There fore, such features have no direct and necessary relation with the method for preparing the medicament; they are not technical features of the use for the preparation of a medicament, and have no limiting effect on it.

The above decision of the Supreme Court is not very surprising, as ever since the Higher Court made the judgment on patent ZL94194471.9, judicial circles have taken different views on the judgment (Tong Shu, China Patents and Trademarks No 4, 2009, pages 50- 53). Nevertheless, the ruling is important in that it is the first time the Supreme Court has made its position clear on the limiting effect of dosing regimen features on second medical use claims. In the present case, the Supreme Court explicitly endorses the examination standard implemented by SIPO on this issue.

Beyond the codified laws

It is worthwhile to note that in the invalidation proceedings of this case, the patentee submitted the judgment of the Higher Court on patent ZL 94194471.9, and requested the PRB to examine this case according to the Higher Court's opinion. As expected, the PRB declined to follow it, and the Supreme Court did not make any comments on this issue. Understandably, China is not a common law country and has no legal tradition to stare decisis, and only the codified laws can be applied by the court in trials. Nevertheless, considering the authority of the Supreme Court in the judicial system, the attitude of the Supreme Court supporting the examination standard of SIPO on this issue will very likely be followed by lower courts in the future. It is believed that, in future, if the patentee wishes to challenge this examination standard through judicial channels, there would be only a very slim chance of success.

Originally published by www.managingip.com

Jiancheng Jiang

Jiancheng Jiang is a patent attorney and attorney-at-law whose practice area covers drafting, prosecution, re-examination, invalidation, litigation, enforcement and strategy in a wide variety of technical IP areas, particularly biochemistry, biotechnology, pharmaceutics, and organic chemistry.

Jiancheng received his BS degree in biochemistry from Peking University, Beijing, and his MS degree in biochemistry from the Graduate School of the Chinese Academy of Sciences, Beijing. He studied European patent law at the European Patent Office and US patent law in the US, and completed integrated law courses at Renmin University, Beijing. He began to practice IP law at China Patent Agent (HK) in 1987. In 2003, he founded Peksung Intellectual Property, and is now the managing partner.

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