| Synovial sarcoma is a soft tissue malignancy of the muscle that primarily affects adolescents and young adults. Due to its low incidence, little advancement has been made in the treatment of this cancer. With an overall survival rate of roughly 40%, the need for new treatments for synovial sarcoma is evident. Further complicating the development of new therapies for thisdisease is its low mutational burden. With a median of 1.7 mutations/Mb, there are fewphenotypical differences between tumor tissue and normal tissue which can be targeted. However, I have identified the cell surface receptor Oncostatin M Receptor (OSMR) as being overexpressed in synovial sarcoma tissue with low expression in non-malignant tissues, making it an ideal target for therapy. Due to the potential for off-target effects and resistancedevelopment with small molecule inhibitors, I elected to develop an anti-OSMR radioimmunetherapy (RIT). Here, I describe the investigation of OSMR in SS as a viable therapeutic target,and the synthesis and characterization of a novel anti-OSMR RIT for use in the treatment of synovial sarcoma. I also show that this novel therapeutic agent has potential as an imaging tool, making it a potential theranostic drug in a cancer which currently has no FDA approved targeted therapies.Key words: Cancer, Sarcoma, Synovial Sarcoma, Targeted Therapy, Immune Therapy, Radiation Therapy, Radioimmune Therapy, Oncostatin M Receptor, Translocation Mutation, Fusion Protein, Oncoprotein, Metastasis, Mutational Burden, SS18-SSX, t(X;18) |