Immunomedics Reports Preliminary Results From Pretargeted Imaging Study in Patients With Metastatic Breast Cancer

Immunomedics, Inc.,

today announced that a new pretargeted imaging system developed by IBC Pharmaceuticals, Inc. (IBC), the Company's majority-owned subsidiary, has the potential of offering better definition of breast cancer (BC) metastasis when compared to conventional imaging methods. Different imaging methods are available to detect BC recurrence, but several new noninvasive antibody-based imaging methods are currently being investigated. These include IBC's pretargeted imaging system based on TF2, in combination with a radiolabeled peptide for the positron emission tomography (PET) imaging of BC. TF2 is a bispecific antibody created by the Company's patented DOCK-AND-LOCK® protein conjugation technology to bind to the carcinoembryonic antigen (CEA or CEACAM5) expressed by BC cells, and the peptide IMP288. The objective of this pilot study was to evaluate the potential of TF2 and IMP288 radiolabeled with gallium-68 (68Ga) in the imaging of advanced metastatic BC, using morphological imaging and 18F-FDG as references. Caroline Rousseau, MD, PhD, of Cancer Research Center Nantes-Angers in Nantes, France, presented preliminary results from this investigator-sponsored study at the 2014 San Antonio Breast Cancer Symposium in San Antonio, TX. Eleven BC patients, assessed in 4 cohorts, were first administered TF2 followed by 68Ga-IMP288 24 to 30 hours later. Patients then underwent whole-body immuno-PET and computed tomography (CT) scanning 1 and 2 hours after injection of the radiolabeled peptide. In addition to thoracic-abdominal-pelvic CT and FDG-PET/CT, bone and brain magnetic resonance imaging (MRI) were also performed in some cases. ImmunoPET (IPET) imaging with TF2 and 68Ga-IMP288 demonstrated a high sensitivity for liver, lymph nodes, and bone metastases, and a higher overall sensitivity (93.2%) than FDG PET (88.5%) and CT (71.9%) (except for lung). "These results demonstrate the promise of anti-CEA pretargeted immuno-PET for staging metastatic CEA positive BC patients," remarked Cynthia L. Sullivan, President and Chief Executive Officer of Immunomedics.