Immunomedics Reports Clinical Results of Pretargeted Radioimmunotherapy of Colorectal Cancer
- Category: Antibodies
- Published on Monday, 02 April 2012 21:50
- Hits: 174
CHICAGO, IL, USA I April 2, 2012 I Immunomedics, Inc. (Nasdaq:IMMU - News), 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 reported that colorectal cancer can be safely, specifically and rapidly targeted with TF2 bispecific antibody and a radiolabeled peptide, with limited toxicity to the patient. Results from the Phase I clinical study were reported at the 2012 Annual Meeting of the American Association for Cancer Research by investigators from the Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
TF2 is a bispecific antibody created by the Company's patented Dock-and-Lock (DNL) conjugation technology. In addition to targeting the carcinoembryonic antigen (CEA or CEACAM5) expressed by many human cancers, TF2 has been engineered to recognize a small peptide that carries radioactivity. This allows the injection of radioactivity to be separated from the administration of the tumor-targeting bispecific antibody, a concept known as pretargeting.
Pioneered by IBC Pharmaceuticals, Inc., the Company's majority-owned subsidiary, pretargeting has the potential advantage of delivering increased radiation dose levels selectively to the tumors while minimizing the body's exposure to radiation's harmful side effects. The objective of the Phase I study is to optimize the dose schedule of a pretargeting system involving TF2 and the hapten-peptide, IMP288, which was labeled with the therapeutic radioisotope, lutetium-177.
Four cohorts, with five patients with advanced colorectal cancer (CRC) per cohort, were enrolled in this first human study to determine how changing the TF2 dose, the interval between the administration of TF2 and IMP288, and the amount of IMP288 administered impacted the targeting of the radiolabeled IMP288, as well as assessing the safety and toxicity of this pretargeting system. At the time of reporting, results with 75 or 150 mg of TF2 followed 1 or 5 days later with 25 or 100 ug of IMP288 were presented.
Pretargeting with TF2 produced rapid localization of IMP288 in the tumor lesions. All known tumor masses were visualized, with limited kidney retention and no accumulation of activity in other normal tissue. Both TF2 and radiolabeled IMP288 cleared rapidly from the blood. Consequently, toxicity was generally very mild, with only two patients showing grade 3 - 4 thrombocytopenia. Overall, this study has provided important insights in how to modify the pretargeting conditions to improve tumor localization.
"We believe these preliminary clinical findings corroborate the advantage of pretargeting we have observed preclinically over traditional antibody-directed radiation therapy in the delivery of higher therapeutic doses to tumor sites without simultaneously raising the toxicity profile of the treatment," commented Cynthia L. Sullivan, President and Chief Executive Officer. "We are in the process of preparing to launch a new clinical study of TF2 and pretargeting in the United States for the treatment of patients with metastatic colorectal cancer," Ms. Sullivan added.
Immunomedics is a New Jersey-based biopharmaceutical company primarily focused on the development of monoclonal antibody-based products for the targeted treatment of cancer, autoimmune and other serious diseases. We have developed a number of advanced proprietary technologies that allow us to create humanized antibodies that can be used either alone in unlabeled or "naked" form, or conjugated with radioactive isotopes, chemotherapeutics, cytokines or toxins, in each case to create highly targeted agents. Using these technologies, we have built a pipeline of therapeutic product candidates that utilize several different mechanisms of action. We also have a majority ownership in IBC Pharmaceuticals, Inc., which is developing a novel Dock-and-Lock (DNL) methodology with us for making fusion proteins and multifunctional antibodies, and a new method of delivering imaging and therapeutic agents selectively to disease, especially different solid cancers (colorectal, lung, pancreas, etc.), by proprietary, antibody-based, pretargeting methods. We believe that our portfolio of intellectual property, which includes approximately 190 patents issued in the United States and more than 400 foreign patents, protects our product candidates and technologies. For additional information on us, please visit our website at www.immunomedics.com. The information on our website does not, however, form a part of this press release.