Patentability of polymorphic compounds: an analysis based on relevant decisions by the EPO Board of Appeal.

The present study analyzes how the European Patent Office (EPO) Boards of Appeal evaluate the patentability of polymorphic chemical compounds, with a focus on novelty (Article 54 EPC) and inventive step (Article 56 EPC). The paper utilizes leading and recent EPO decisions - including T 777/08, T 1684/16, T 1326/18, T 672/21, T 1994/22, T 2086/21, and T 2157/21 - to synthesize the evidentiary demands and propose a structured account of when polymorph claims can be patentable. Polymorph claims are tipically patentable when a specific solid form is novel and delivers an unexpected technical advantage (often understood as a valuable balance of properties) that can be credibly attributed to the form as claimed.