New biological entities (NBEs, therapeutic proteins such as interferons or antibodies) are much more complex than new chemical entities (NCEs), the classic “chemical†active ingredients. First, they are much larger. The average molecular weight of antibodies is ~150,000 g/mol. Second, most NBEs contain three-dimensional structural elements — with the protein secondary and tertiary structure being the most prominent, but quaternary structures are also known for some. The 3D structures are essential for correct bioactivity (1), but they are…