About IGM Biosciences, Inc. IGM Biosciences (Nasdaq: IGMS) is a clinical-stage biotechnology company committed to developing and delivering a new class of medicines to treat patients with autoimmune and inflammatory diseases. The Company’s pipeline of clinical and preclinical assets is based on the IgM antibody, which has 10 binding sites, compared to conventional IgG antibodies with only 2 binding sites. We have created unique IgM antibodies with high selectivity, affinity, and avidity that may redefine what is possible for therapeutic antibody medicines. We are committed to exploring how the unique structure and binding properties of the IGM antibody can improve outcomes for patients with these serious conditions. The Company also has an exclusive worldwide collaboration agreement with Sanofi to create, develop, manufacture, and commercialize IgM antibody agonists against oncology, immunology, and inflammation targets. For more information, please visit www.igmbio.com. Imvotamab in Autoimmune and Inflammatory Diseases Imvotamab is a bispecific T cell engaging IgM antibody targeting CD20 and CD3 proteins. We believe that Imvotamab, with its 10 binding units for CD20, may successfully bind to CD20 expressing B cells with more power (avidity) compared to an IgG bispecific antibody with only one or two binding units for CD20. Our preclinical studies suggest that Imvotamab may offer the potential for deeper depletion of B cells, including those in low CD20 expressing cells, than currently approved antibody therapies. We are evaluating Imvotamab in Phase 1b clinical trials of Imvotamab in severe systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and idiopathic inflammatory myopathies (myositis).