ORLANDO, Fla., June 1, 2009 (GLOBE NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced that subcutaneous injections of low doses of veltuzumab in patients with non-Hodgkin's lymphoma (NHL) or chronic lymphocytic leukemia (CLL) produced a slow and efficient delivery of pharmacologically active antibody into the blood, that the treatment was well tolerated, and that NHL patients showed objective responses at all doses tested.
"We believe the subcutaneous formulation offers doctors and patients significant benefits including ease-of-use, better compliance and lower side effects," said Cynthia L. Sullivan, President and CEO. "We expect to complete this study before the end of this calendar year, and are in the process of developing a registration pathway for veltuzumab in oncology," added Ms. Sullivan.
For the 15 NHL patients reported at the conference, 53% had an objective response, and 27% a complete response (CR/CRu). In follicular lymphoma, 7 of 12 patients (58%) had objective responses, with 3 patients (25%) having complete responses. These findings were similar to the Phase I/II results using the intravenous formulation recently published by the Company (please refer to www.immunomedics.com/news_pdf/2009_PDF/PR05182009.pdf). Thus, despite the small number of patients, it appears that the subcutaneous formulation of veltuzumab can be effective against NHL.
For CLL, there were no objective responses in 8 patients reported at the conference. However, 50% of patients had stable disease for more than 12 weeks. An adequate dosing schedule has yet to be determined for this group of patients.
Subcutaneous injections of veltuzumab were given 2 weeks apart for a total of 4 doses. Patients received veltuzumab at one of three dose levels: 80, 160, or 320 mg. Efficacy was assessed at 4 and 12 weeks post treatment, with responding patients continuing follow-up. The injections were well tolerated with only transient, mild, grade-1 treatment-related adverse events.
Low doses of subcutaneously administered veltuzumab was also reported previously to be active in patients with immune thrombocytopenic purpura, an autoimmune disease, producing durable platelet increases in some patients that are continuing after one year (please refer to www.immunomedics.com/news_pdf/2008_PDF/PR12082008A.pdf).
About Veltuzumab
As a second generation humanized anti-CD20 antibody, veltuzumab was constructed using the same donor frameworks as epratuzumab, the Company's humanized anti-CD22 antibody. Consequently, similar to epratuzumab, veltuzumab can be infused rapidly and has been well tolerated by patients. Veltuzumab's complementarity-determining regions (CDRs) are identical to rituximab, except for one amino acid residue (aspartic acid instead of asparagine) in CDR3's heavy chain variable region. Veltuzumab demonstrated slower off-rates in three human lymphoma cell lines, and mutation studies confirmed that the difference was related to the single amino acid change. Although antiproliferative, apoptotic, and antibody-dependent cellular cytotoxicity effects seemed similar in vitro, veltuzumab demonstrated increased complement-dependent cytotoxicity in one of three lymphoma cell lines and was significantly more effective in vivo than rituximab in three human lymphoma models. Even at low doses, veltuzumab effectively depleted B cells in cynomolgus monkeys and controlled tumor growth in mice bearing human lymphoma xenografts.
About Immunomedics
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 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 134 patents issued in the United States and more than 300 other patents issued worldwide, 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.
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.