SAN FRANCISCO, Jan. 24, 2011 (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 that combining antibody-directed drug and radionuclide therapeutics for pancreatic cancer improved efficacy in preclinical studies with minimal toxicity. Results from these investigations were presented at the 2011 Gastrointestinal Cancers Symposium.
Two of the Company's proprietary humanized antibodies were involved in this research. Clivatuzumab, which selectively targets pancreatic cancer, has shown in preclinical and early clinical studies promising therapeutic activity when labeled with yttrium-90 (Y-90) and in combination with gemcitabine. hRS7 has been shown to internalize into cancer cells when bound to its receptor, EGP-1, or TROP-2, making it an attractive antibody for delivery of cytotoxic drugs.
Since TROP-2 has higher expression in lung, breast, prostate, ovarian, colorectal, pancreatic and cervical cancers than in normal tissues, the Company has previously conjugated SN-38, the active metabolite of irinotecan approved as a chemotherapeutic agent for metastatic colorectal cancer, to hRS7 for targeted treatment of cancer. In preclinical studies, hRS7-SN-38 has demonstrated potent therapeutic effects against lung cancer. (Please refer to the Company's press release at for more information).
Using nude mice bearing human pancreatic cancer cells as a model, the goal of the current studies was to evaluate the possibility that hRS7-SN-38, at effective, yet non-toxic doses, could augment therapeutic responses with Y-90-labeled clivatuzumab tetraxetan. Clivatuzumab-SN-38 conjugate was also included in these evaluations.
Irinotecan, given at a dose that contained the same amount of SN-38 as the antibody-drug conjugates (ADC), was not effective in controlling tumor growth, while each ADC alone was able to inhibit tumor growth significantly compared to untreated animals. When ADC was combined with the radiolabeled antibody, time to progression (TTP) improved considerably and more animals were tumor-free. Importantly, an effective ADC dose can be combined at the maximum tolerated dose (MTD) of Y-90 clivatuzumab tetraxetan with minimal additional toxicity.
The combination of ADC and radiolabeled antibody therapies were best when the latter was given 1-2 weeks before, the same day, or within 1 week after the ADC treatment, but delaying radioimmunotherapy (RAIT) for 2 weeks after ADC treatment reduced efficacy. Clivatuzumab can be used in the combination treatment both as RAIT and as an ADC without losing effectiveness. Overall response was further enhanced when gemcitabine was added to the combination therapies.
"We believe these results demonstrated the feasibility of using ADC alone or as a combination with Y-90 clivatuzumab for the treatment of pancreatic cancer, thus offering an additional tool for the management of this dismal disease," commented Cynthia L. Sullivan, President and Chief Executive Officer.
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 154 patents issued in the United States and more than 375 other patents issued worldwide, protects our product candidates and technologies. For additional information on us, please visit our website at . The information on our website does not, however, form a part of this press release.
This release, in addition to historical information, may contain forward-looking statements made pursuant to the Private Securities Litigation Reform Act of 1995. Such statements, including statements regarding clinical trials, out-licensing arrangements (including the timing and amount of contingent payments), forecasts of future operating results, and capital raising activities, involve significant risks and uncertainties and actual results could differ materially from those expressed or implied herein. Factors that could cause such differences include, but are not limited to, risks associated with new product development (including clinical trials outcome and regulatory requirements/actions), our dependence on our licensing partners for the further development of epratuzumab for autoimmune indications and veltuzumab for non-cancer indications, competitive risks to marketed products and availability of required financing and other sources of funds on acceptable terms, if at all, as well as the risks discussed in the Company's filings with the Securities and Exchange Commission. The Company is not under any obligation, and the Company expressly disclaims any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise.
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