Judicial Precedent on Existence/Inexistence of Limiting Factors
February 2, 2010
Harakenzo World Patent&Trademark
By K. Matsumura, Patent Attorney
Receiving a notice of reasons of refusal for violating an inventive step, as one of the countermeasures to be taken, we would consider existence/inexistence of conditions that inhibit to relate different cited references with each other, or to replace a part of a structure of the cited reference by a part of a structure of the other reference (hereinafter referred to a limiting factor). Meanwhile, it is also said that the criterion of the limiting factors is strict and the existence of the factor is not easily acknowledged. Let me introduce here one of the recent judicial precedents as an example of judicial judgment on limiting factors. In this judgment, a plaintiff's claim was rejected in which claim there is a limiting factor in using a particular medicinal property as a dietary supplement, since the property potentially has a malignant influence on humans.
1. Case
Suit against Decision of Refusal 2008 (gyo-ke) No. 10377 (Judicial Decision on October 28, 2009)
2. Overview from trial decision to judicial decision
The plaintiff filed a suit against a Decision of Refusal with regard to the patent application claiming "A health supplement comprising a health supplementary amount of two or more of natural phyto-oestrogen selected from genistein, daidzein, biochanin A, formononetin and their glycoside, for use as prevention or treatment of premenstrual syndrome, perimenopausal syndrome, and/or benign breast disease"(claim 1)(priority date: May 19, 1992).
In the decision of refusal, an inventive step of the invention (the invention according to claim 1) was rejected since persons who have common knowledge could have easily made it.
・Document 1 (Japanese patent application publication Tokukaihei No. 2-160722) describes that:
(1) Free flavonoid, glycoside etc. have pharmacological properties such as platelet aggregation inhibition action, estrogenic activity etc.;
(2) flavonoid is a safe compound that exists in natural products and also in diets in small quantity and thus it is suggested to be used for therapeutic purposes;
(3) Flavonoid includes isoflavone type (daidzein, genistein, genistin etc.).
・Document 2 (Japanese patent application publication Tokukaisho No. 60-48924) describes that one significant cause of osteoporosis is a decrease of estrogen secretion in a postmenopausal woman, and the daidzein which has milder estrogenic activity compared to an estrogenic agent of a conventional therapeutic agent, can be used for the treatment of osteoporosis without side effects caused by the conventional agent.
・Document 3 (Japanese patent application publication Tokukaisho No. 59-199630) describes that the decrease of estrogen secretion causes not only an osteoporosis but also a climacteric disorder (also referred to as a postmenopausal symptom), and that a main treatment method for the climacteric disorder was to compensate an ovarian hormone for a conventional synthetic estrogenic agent etc.
On the basis of these references, it could have easily been made by persons skilled in the art to substitute the synthetic estrogenic agent for phyto-oestrogen having milder estrogenic activities such as daidzein, and to examine the amount thereof that would not cause any side effects in use.
The plaintiff appealed against the above opinions that the person skilled in the art recognized that isoflavone may have potentially exerted harmful influence on human and thus there was a limiting factor to use isoflavon as a health supplement based on the following reasons (1) and (2).
(1) According to eight references, phyto-oestrogen physiologically exerts harmful effect on mammals such as cattle, sheep and cheetah. Since it is a fundamental hypothesis in toxicology that the adverse effect by a chemical substance in an animal body is generally identical to the one by the same substance in a human body, it is expected that the phyto-oestrogen also exerts the above effects on human.
(2) The appeal decision stated that the above eight references did not affect the judgment on whether or not it had been easily made since the references only described about animals. However, it is well known that a preclinical test is a test for administering a medicine to a particular range of mammals in order to calculate its toxicity to humans. Thus, the appeal decision ignores a standard method for the evaluation in administering potentially toxic compound to human (preclinical test using nonhuman mammals).
The plaintiff provides the following examples as grounds for the appeal of the physiological harmful effects of phyto-oestrogen on humans. One reference describes that phyto-oestrogen in cheetah's diets causes hepatic function disorder in cheetahs. Thus it should be considered that it may also cause the hepatic function disorder in humans. When an adult cheetah ingested weak phyto-oestrogen around 50mg/day, obstruction of a vein was found, and the cheetah and an adult human female have substantially same average weight. In one example of the subject description, a human's ingestion of 50-100mg isoflavon per day is reported, so the adverse effect on the cheetah may also be exerted on humans.
In response to the plaintiff's appeal, the Intellectual High Court cites that according to various documents published prior to the subject application, genistein daidzein and formononetin of the application are administered to humans as an osteoporosis therapeutic agent, an immunosuppressing agent, an anticancer agent, a prophylactic and improving agent etc., and therefore considers that
"while phyto-oestrogen used in the subject invention is known to have a correlation to sterility, mastitis or hepatic function disorder in animals and the same effect on human has been pointed out, it is confirmed that at the time of filing of the subject application, it performs useful physiologic action to various human diseases, for example it will respond to a cancer with an appropriate dosage." and decided that
"given that phyto-oestrogen used in the subject invention is included in soy beans, which humans routinely ingest, if at the time of filing the application you ingest the same amount of phyto-oestrogen of the subject invention as the amount ingested by eating soybeans, except the case of ingesting a large amount, it is not expected that the person skilled in the art will recognize its adverse influence on humans. Therefore, it is not admitted that there is a limiting factor at the time of filing the subject application."
3. View
As explained above, according to the judicial judgment, if a person skilled in the art recognizes that phyto-oestrogen is a useful substance to humans depending on the usage, the fact that a person skilled in the art recognizes its potential toxicity to humans is not considered to be a limiting factor for the use of phyto-oestrogen as an agent of climacteric disorder. The Japan Patent Office argued "their use as a therapeutic agent shall not be prevented due to the generation of adverse effects or excess symptoms. (…) as long as a useful pharmacological action of phyto-oestrogen is known and there is room for examining dosage and administration to activate the action, the intension to use phyto-oestrogen will not be disturbed and thus there is no limiting factor for the trial of using phyto-oestrogen as a medicinal agent with its appropriate dosage." In the judgment this argument turned out to be acknowledged.
The limiting factor is considered to be accrued in case that a person skilled in the art would not expect to combine different references with each other since a technical prerequisite will be failed by combining them, or it is technically common that a disadvantage will occur by combining them (Reference 1). Using a chemical compound as a medicinal agent and for minimizing the issue often causes the issue of the adverse effect, the dosage and administration is determined. In view of such circumstances, I think the decision of confirming inexistence of a limiting factor reasonable since combining references with each other does not cause a failure of technical prerequisites as long as using phyto-oestrogen with an appropriate dosage, and generate no disadvantage.
A relatively recent judicial precedent, in which the existence of the limiting factor was acknowledged, is for example a "Suit against trial decision 2007 (gyo-ke) No. 10007 (Forming method of sealing material for fuel cell), which is not a biotechnological invention. In this case, both the subject invention and the cited invention relates to a forming method of sealing material for a fuel cell, which comprises a process for forming and integrating a cross linked rubber thin film into a separator surface around edges. In the subject invention, the material of the separator is carbon graphite and a screen-printing is used as an application method of rubber solution. While in the cited reference, the material of the separator is metal and an injection molding is used as an application method of rubber solution.
According to the trial decision, a separator for fuel cells made of carbon graphite and a separator made of metal are both well known and have a common objects with regard to a working property. Thus, it has been easily made to replace a metal material with a carbon graphite material and to replace an injection molding with a conventional forming and integrating method of screen-printing.
However, the Intellectual High Court acknowledged the existence of a limiting factor for the following reasons:
" A separator for a fuel cell made of a carbon is subject to breakage due to its weak property and low mechanical strength. In the cited invention, it is assumed that thin metal sheet is inserted and applied to the injection molding under high pressure. It is thus expected that if the carbon graphite was used in an injection-molding device, the separator made of carbon graphite would likely to be damaged due to its mechanical weakness. Therefore, in the injection forming process for injection molding described in the cited invention, applying the separator made of carbon graphite instead of metal to the injection molding device shall hold a technical limiting factor. Further, in view of such circumstances, even if a screen printing is known as an application method of rubber solution, it cannot be said that it is easily made to replace the metal material for the separator with the carbon graphite material and at the same time replace the injection molding with the screen printing."
In this case, the judge seems to consider that it is not easily made by the person skilled in the art to combine the cited references and the conventional technique, since a technical prerequisite "it is possible to apply carbon graphite to injection molding under high pressure as described in the cited invention" fails by combining them. Meanwhile, this case does not include the fact that on one hand, combining the cited references and the conventional technique causes disadvantage, and on the other hand, it may be useful. In this regard, this case is different from the former case and created a great difference in acknowledgment of the limiting factor.
--- Reference ---
Koji Manaka "Department of Appeal, Investigation Commission on Inventive Step", Japanese Patent Office Society, 245m 20-35, 2007
STAFF
大阪本部
