An extended-Release preparation (ER) means a preparation which controls an active component’s emission rate, time and area in order to reduce side effects or decrease medicine injection frequency.
The Supreme Court recently announced a judgment of remanding after reversal of a patent court decision which decided that an extended-release preparation patent in which pharmacological data based on an animal experiment was described did not meet the requirements regarding description (judgment 2016hu601 announced on October 25, 2018 by Supreme Court).
(2) Outline of case
The subject patent invention refers to ‘an extended-release preparation composition comprising octreotide or a pharmaceutically-acceptable salt thereof as an active ingredient and two different polylactide-co-glycolide polymers (PLGAs)1’ .
In the subject patent invention’s specification, it is described that the claimed pharmaceutical composition allows release of the active ingredient over a period of more than three months, preferably between three and six months, and that during the release of the active ingredient, the blood plasma levels of octreotide are within the therapeutic range’. The specification also provides working examples regarding the method for an experiment in which the compositions were administered to rabbits and blood plasma levels of octreotide were measured for 96 days, as well as the data obtained from the experiment.
A plaintiff requested an invalidation trial with the Intellectual Property Tribunal on the grounds that the subject patent invention does not meet the description requirement and lacks novelty and inventive step; however, the Intellectual Property Tribunal made a decision that the novelty and inventive step of this patent invention are not denied, and also that the detailed description and claims meet the description requirement.
The plaintiff filed a suit with the patent court for cancellation of the trial decision on the above mentioned grounds, and the patent court judged that it is difficult for a person having ordinary skill in the art to which the invention pertains (hereinafter ‘skilled person’) to accurately understand, based on the contents of the subject specification such as pharmacological data, etc., the effects of the octreotide extended-release preparations of the subject invention without specific knowledge or going through excessive experiments. Also, the court judged that a skilled person can hardly assume the blood concentration aspect for humans or the long term treatment effect towards humans from the pharmacological data regarding rabbits described in the subject specification.
I.e., A judgment was made that the effect of the invention was not described thoroughly enough in the subject specification for a skilled person to be able to implement the invention, so the registration of the subject invention was invalidated due to its violation of Article 42 (3) of the Patent Act.
(3) Supreme Court’s decision
Regarding the description requirement in relation to extended-release preparations, the Supreme Court remanded after reversal by deciding as follows towards applying the legal principles of the description requirement for product inventions2
② In order to confirm continuity of an extended-release preparation’s remedial effect, one needs to check whether blood concentration of the active ingredient is maintained continuously after injecting the extended-release preparation. The method of predicting blood concentration in the human body through measurement results of blood concentration experiments in certain animals was widely utilized in the field of extended-release preparations inside and outside of the country at the time of the priority date of the subject invention, and various filings and registrations of patents were proceeded based on such animal experiment results.
③ As described in the specification of the subject patent invention, if blood concentration in rabbits was continuously maintained over a certain level during approximately 3 months after injecting the proper amount of octreotide into a rabbit, a skilled person could infer that the blood concentration would be continuously maintained for a similar period in humans as well based on such result and could reproduce it via a similar method.
④ It is common general technical knowledge that remedial effects of an active ingredient are proportional to medicine concentration in the active site, so it cannot be seen that a skilled person would experience any special technical difficulty in adjusting the injection of an extended-release composition in order to maintain the required therapeutic range based on the subject invention’s specification.
⑤ Since a skilled person could produce and use the extended-release composition of the subject patent invention and sufficiently anticipate the effect of the invention based on the technical standard at the time of the filing of the patent application, the description requirement of the patent specification can be considered to have been satisfied even if clinical trial results, etc. towards humans were not described in the specification.
(4) Significance of judgment
Regarding the description requirement for an ‘extended-release composition’, there is significance that the Supreme Court applied the legal principle of the description requirement for a ‘product invention’, not the strict description standard regarding pharmacological data in a medical use invention.
Further, the Supreme Court’s legal principle for a ‘product invention’ description requirement can be applied for describing the specification of a dosage invention which adds a constitution having technical characteristics in the preparation’s physical form for improving absorption and elution rates of the pharmaceuticals of which pharmaceutical efficacy, such as the active ingredient’s mechanism for applying the medicine, is publicly known, as well as for the extended-release composition in the subject patent invention.
1 Octreotide is a drug having pharmaceutical efficacy on reducing symptoms of carcinoid syndrome which is related to remedying hyperpituitarism and stomach/enteritis/enteritis endocrine tumors. Such pharmaceutical efficacy was well known before the priority date of the subject patent invention. Polylactide-co-glycolide polymer (PLGA) is a copolymer which is used in remedies due to its biodegradability and biocompatibility.
2 ‘Executing’ a ‘product invention’ means the act of producing and using that product, so the description requirement regulated by Article 42 (3) of Patent Act can be satisfied under the following case that if a skilled person can produce and use a product invention based on the description of the invention without adding excessive experimentation or special knowledge in light of the technical standard at the time of the filing of that patent application, and also if the skilled person can sufficiently anticipate occurrence of the effects of the invention based on the technical standard at the time in which the invention was filed, even if it was not proven by concrete experiment (judgment 2014hu2061 announced on May 26, 2016 by supreme court).