“Tylosin”

• 1. When determining whether an invention is non-obvious, the scope and content of the prior art, differences between the invention at issue and the prior art, and the level of technological expertise of a person with ordinary knowledge in the art (hereinafter referred to as an “ordinary technician skilled in the art”) should be determined based on the relevant documents including the records of the case. Consequently, non-obviousness should be assessed based on whether the invention in question is different from prior art in light of the level of technology, whether such a difference could be overcome, and if it could be easily invented based on the prior art. In such cases, the question of whether an ordinary technician skilled in the art could easily create the invention should not be determined on the premise that she/he has knowledge of the technology because the specification of the invention has already been disclosed.

• 2. Polymorph screening, which examines whether a compound has various crystalline forms, so-called crystalline polymorphs, is a common practice in the preparation design of pharmaceutical compounds. In the field of pharmaceuticals, it is necessary to discover the unique characteristics of the molecule when determining the non-obviousness of a so-called invention related to crystalline forms using a specific crystalline compound that has the same chemical structure as the already disclosed compounds, but a different crystalline form in its patent claim. However, it cannot be concluded that the complexity of constructing the invention related to crystalline forms should be denied for the sole reason that the invention in question and the prior-art invention are the same compound. The fact that polymorphic screening is generally undertaken should be differentiated from the question of whether a specific crystalline form of the invention related to crystalline forms may be easily invented/replicated. Since it is not easy to predict the effect of an invention such as an invention related to crystalline forms, in the field of pharmaceuticals it is necessary to consider the effect of the invention when determining the complexity of the composition; if the effect of the invention in question is considerably substantial compared to the prior art, this can be convincing evidence to infer the complexity of structuring.

• 3. When determining the complexity of a composition, it is crucial whether an ordinary technician skilled in the art can easily derive the composition of an invention related to crystalline forms from prior art; for such an examination, the following factors and other equivalent factors should be considered comprehensively based on the records: the technical significance and unique effect of the invention related to the crystalline forms in question; the structure and manufacturing method of a specific crystalline form claimed in the invention; the content and features of the prior art; and the level of technical expertise of an ordinary technician skilled in the art and typical modes of polymorphism screening of the prior art at the time of filing the application. On the basis of the above factors, it should be assessed whether the crystalline polymorphism of the prior art is known or expected; whether a specific crystalline form claimed in the invention can be learned from, inferred from, or motivated by the relevant technical documents; whether a specific crystalline form of the invention related to crystalline forms is included in the scope of the crystalline polymorphism that can be examined through normal polymorphism screening of the prior-art compound; and whether such a crystalline form has an unexpected beneficial effect.

• 4. When the effect of the invention related to crystalline forms is qualitatively different from the effect of the prior-art compound, or has a significant difference in quantity, the non-obviousness is not denied. The distinct effect of an invention related to crystalline forms should be determined based on an effect that may be recognised or inferred by an ordinary technician skilled in the art, and if the effect is unexpected, it may be specifically claimed and proved by submitting additional experimental data after the filing date.