Horizon Discovery Group plc announced that its cGMP-compliant CHOSOURCE™ platform has played a key role in generating a stable cell line for the development of an immunotherapy for autoimmune diseases. Horizon’s pharmaceutical-grade, stable Chinese Hamster Ovary (CHO) cells delivered high yields of monoclonal antibody for LAG-3 immunotherapy, enabling Immutep and Batavia Biosciences to reach an important milestone in the preclinical development of the compound. Horizon’s gene-edited Glutamine Synthetase (GS) knockout CHO K1 cell line expression system, offered by Batavia Biosciences as part of its STEP®-mAb service, was used to generate a high yielding cell line for Immutep’s IMP761 product candidate, an agonist antibody targeting the immune checkpoint lymphocyte activation gene (LAG)-3. LAG-3 controls the signaling between specific immune cells, T cells and antigen presenting cells, which are responsible for the adaptive immune response, making it a promising focus for novel cancer therapies or for the treatment of autoimmune conditions, such as inflammatory bowel diseases, rheumatoid arthritis, and multiple sclerosis. Horizon’s well-established GS expression system facilitates the development of stable cell lines for the expression of antibodies and other recombinant proteins and is recognized in the industry and by regulators as suitable for high yield biomanufacturing. Its CHOSOURCE biomanufacturing platform helps companies to move from the DNA sequence of their potential biotherapeutic to clinical manufacturing as simply and rapidly as possible. The platform is versatile and suitable for a broad range of monoclonal antibody therapeutics, delivering higher-than-anticipated yields of less commonly used IgG4-based antibodies, such as IMP761.