WASHINGTON, April 10, 2013 (GLOBE NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company primarily focused on the development of monoclonal antibody-based products for the targeted treatment of cancer, autoimmune and other serious diseases, today announced the development of novel T-cell redirecting agents made as DOCK-AND-LOCK™ (DNL™) complexes by tethering a single-chain variable fragment (scFv) that binds to CD3 on T cells to different antibody fragments that target tumor antigens. The preclinical study was presented at the 2013 Annual Meeting of the American Association for Cancer Research (AACR). The use of bispecific antibodies to redirect T cells for the killing of targeted tumor cells has shown considerable promise both preclinically and clinically . The Company has previously reported the generation of (19)-3s, a prototype bispecific antibody that binds to CD19 on B cells and CD3 on T cells, using the Company's patented DNL TM platform technology. (19)-3s has demonstrated in vitro the ability to direct T cells to destroy CD19-expressing B cells by linking them together. (For more information, please refer to the Company's press release at www.immunomedics.com/pdfs/news/2012/pr12122012.pdf ). In the current study, (19)-3s was found to be highly effective in vivo. In an animal model of human lymphoma, 6 of the 8 animals that were treated with 43 micrograms of the DNL TM-derived bispecific antibody for five doses remained alive, with 5 of 8 animals tumor-free at the end of the study. Encouraged by these results, a panel of novel T-cell redirecting bispecific antibodies were created by DNL TM as potential therapeutics for solid malignancies. Three DNL TM complexes, designated (14)-3s, (E1)-3s, and (M1)-3s, were prepared by linking anti-CD3 scFv to humanized antibody fragments with specificity for CEACAM5, TROP-2, and PAM4-antigen, respectively. All three biomarkers are expressed in many solid tumors. (14)-3s and (E1)-3s both exhibited anti-tumor activity in animal models of human colonic and pancreatic cancers, respectively. "The modular nature of DNL TM has allowed us to rapidly produce a large number of complexes as T-cell redirecting agents for various malignancies," commented Cynthia L. Sullivan, President and Chief Executive Officer. "We are currently evaluating the in vitro and in vivo properties of these DNL TM complexes in cognate solid tumors," Ms. Sullivan added. At the same AACR meeting, a study on the mechanism of action of epratuzumab was also presented.