There is currently a favourable market situation for the development of biosimilar monoclonal antibodies and the development of technologies for their production. Specifically, the patents for the Celtolizumab pegol protein innovator expire a few years later, both in the US and in Europe. The development of a technology for the production of this protein is therefore commercially viable. The main problem is the low productivity of the innovator technology — about 20 ml/L yield. In the current biotechnology market, such productivity is unacceptably low, leading to high production costs and high product prices. The aim of the project is to develop a technology for the production of Celtolizumab pegol protein that can achieve a protein yield of approximately 200 mg/L from the biosynthesis process. In order to achieve this result, it is necessary to carry out a whole series of R & D activities in which the E.coli line, capable of producing protein in large quantities, would be investigated and developed. It is also necessary to examine the cultivation parameters of the E.coli cell line that will allow achieving such a high protein yield. Finally, it is necessary to develop biosynthesis, purification and pegaging technology up to 3000 L to ensure that E.coli’s ability to synthesise protein in large volumes is preserved in the desired quantities. The objective of the project is to develop a prototype of Celtolizumab pegol protein production technology and to test it in real-world conditions by producing a trial batch of biosimilar Celtolizumab pegol.