The inventive step in a patent application (applicant: Celator Pharmaceuticals, INC.) disclosing fixed drug ratios for treatment of hematopoietic cancers and proliferative disorders relates to claim 1 limiting ‘administration method and dosage in a subject of intravenously administering 32-134 ㎎/㎡ of cytarabine over a period of 8 hours or less, with a first step of administering on a first day, a second step of administering on a third day and a third step of administering on a fifth day’. (Patent Court Ruling 2018 huh 3925)

The Patent Court ruled that the skilled person would have no difficulty in construing the administration method and dosage of claim 1 by the clinical test to be conducted naturally within the anticipatable scope, given that the administration method and dosage of claim 1 are not beyond the scope anticipated to maintain the pharmacological effect of cytarabine to daunorubicin and to minimize the toxicity or side effects, and also it is within the general creativity for the skilled person to optimize the administration method such as dosage and administration period which can facilitate the administration and maintaining the pharmacological effect of the known drug avoiding the toxicity or side effects.

Additionally, the decision indicated the effects from the scope of ‘32-134㎎/㎡ cytarabine‘ and the administration over a period of ‘1 day, 3 days and 5 days’ in claim 1 is not significant or distinguished to the degree which cannot be anticipated by the skilled person.

To achieve the inventive step for a use invention of administration method and dosage, it needs to achieve the significant or distinguished effects unanticipated by the skilled person, based on the technology level or known technology at the time of filing.

Although administration method/dosage may be acknowledged as a component of invention, it is worth noting that the inventive step could not be acknowledged unless the effects are significant or distinguished enough to the degree unanticipated by the skilled person, when construing the optimal administration method/dosage generally conducted in a clinical test. However, considering the Supreme Court had previously ruled that the transdermal administration of the material having the identical use as above involved an inventive step, it is to be seen to which degree the court would define the scope for the general creativity.