[Review on decision 2016hu830 announced on February 3, 2017 by patent court]
After the substance patent for the anti-impotence drug ‘CIALIS’ (Effective Ingredient: Tadalafil) expired on September 4, 2015, approximately 60 domestic general pharmacists released generic versions of CIALIS. Meanwhile, since the expiration date for Korean Patent Registration No. 0577057 (hereinafter ‘CIALIS dosage patent’) which limits dosage of Tadalafil to a maximum of 20mg per 1 day and Tadalafil contents within unit dosage form to 1~20mg, is April 26, 2020, a majority of domestic generic pharmacists would be liable for a huge amount of compensation for damages if the CIALIS dosage patent were recognized to be valid.
Against this background, domestic pharmacists requested an invalidation trial for the CIALIS dosage patent, and the patent court’s decision on invalidating the corresponding patent was announced on February 3, 2017.
This decision draws special attention since this case was the first case in which the standard of judgment for inventive step regarding usage and dosage became problematic after the Korean supreme court made an en banc decision which recognized a usage and dosage invention of medicine to be within a composition of matter patent (2014hu768 en banc decision, a case to Confirm the Scope of Right).
2. Court’s Judgment
(1) Issue Summary
The defendant (a domestic general company) requested an invalidation of registration trial against the plaintiff on October 23, 2014 with the Korean Intellectual Property Tribunal 2014dang2632 by insisting that Clams 1 to 13 of the subject patent (the CIALIS dosage patent) could have easily been invented by a person having ordinary skill in the art to which the inventions pertain (hereafter ‘skilled person’), so the inventive step of the patent should be denied. Meanwhile, the plaintiff (patentee) requested a trial for correction with the Intellectual Property Tribunal 2015jung113 on November 5, 2015 for amending ‘total amount per 1 day is less than maximum 20mg’ of Claim 1 to ‘total amount per 1 day is 2 ~20mg’ and also to add ‘dose for 1 time per 1 day’ to the front of ‘dosage unit form’ of Claims 5, 6 and 9.
The Intellectual Property Tribunal made a trial decision rejecting the trial for correction on January 25, 2016 by stating that the ‘corrected invention of Claim 1 violates Article 136 (4) of the Patent Act since it could have easily been invented by a skilled person from prior inventions, and in the case that a request for correction is requested against many items, the whole trial for correction cannot be accepted when a part of the many items has a ground for disapproval of correction.’
(2) Patent Court’s decision
The Patent court clearly presents a standard of judgment on inventive step for usage and dosage inventions as follows: 「Finding proper dose or proper dose period, area, route, etc in order to prevent side effects or toxicity and at the same time maintaining the pharmacological effects of a medicine and improving ease of administration of the medicine disclosed in a pharmaceutical invention belong to technical issues for which resolution is essential in this field. The determining process and its method are also well known to skilled persons in the field. If so, optimizing the dose method such as regarding dosage, dose period, etc. within the range of not causing problems, for example toxicity or side effects, in order to solve the issue of increasing efficacy and decreasing side effects of a disclosed medicine, does belong to the range of a skilled person’s skilled creative ability in principle (non inventive step). However, in the case that an advantageous effect caused by a specific dose method or dosage exceeds the predictable range unless there are non specific circumstances, or in the case that a skilled person could not have predicted a specific dose method or dosage in which toxicity or side effects are minimized while maintaining pharmaceutical efficacy, the inventive step will not be denied.」 According to such standard, there was no compositional difficulty in deducing the CIALIS dosage patent by mandatory clinical trial. Furthermore, the inventive step was judged as invalid since the effect within the range of dosage of the CIALIS patent was not prominent or unique.
3. Significance of Judgment
Although the plaintiff appealed against the supreme court on March 10, 2017, the original trial was confirmed due to the supreme court’s judgment of dismissal without hearing on June 29, 2017.
Regarding the UK patent family of this CIALIS dosage patent case, the UK Patents County Court judged the ease of deciding dosage differently. The UK Patents County Court recognized inventive step of the CIALIS dosage patent by stating that in the case of CIALIS, a researcher’s ‘value judgment’ was needed in deciding the dosage of the patent invention to limit the dosage to a specific range, unlike ‘ordinary research’ which decides oral administration dosage of common disclosed medicines, so this case was not an obvious ‘rationally succeedable’ case. Meanwhile, in the case of the Japanese patent family, the JP patent court also recognized inventive step of the said patent; however, the JP Tokyo local court denied the inventive step thereof.
Regarding an invention related to dose method and dosage composition, the possibility of protecting such invention was recognized by the supreme court’s en banc decision 2014hu768. Nevertheless, this decision shows that acquiring recognition of patentability related to dose method and dosage composition is still difficult. Unless there is the specific circumstance described in this decision (i.e. the circumstance that a skilled person could not have predicted the effects depending on dosage such as improvement of efficacy, decrease of side effect or easement of taking medicine), it will be hard to have inventive step for an the invention defined by a dosage limitation.
 Supreme court announced an en banc decision with a confirming scope of right case (patent, 2014hu768 announced on May 21, 2015) as follows: 「In the case that a dosage regimen and a dose are added to a targeted disease or efficacy in a medical use product invention, such dosage regimen and dose do not indicate a medical treatment itself but indicate a medicine’s attribute which makes a medicine product demonstrate its efficacy so that such can be seen as a component giving new meaning to medicines. Since new medical uses such as dosage regimens and dose are added to medical uses, a patent right can newly be given to medicines which have requirements for patentability such as novelty and inventive step, etc.」
 Actavis & Ors v Eli Lilly and Company  EWHC 1955 (Pat) (10 August 2016)
 JP Patent Court invalidation2013-800243
 JP Tokyo local court 2015010113