Immunomedics, Inc. (Nasdaq: IMMU), a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced that Franck Morschhauser, MD, Centre Hospitalier Regional Universitaire de Lille, Lille, France, presented data at the 43rd Annual Meeting of the American Society of Clinical Oncology in Chicago, IL, showing the Company's humanized anti-CD20 monoclonal antibody (hA20) was active in patients with non-Hodgkin's lymphoma (NHL) at a low dose of 80 mg/m2.

Current biological therapy with monoclonal antibodies for NHL includes rituximab, which has been approved at a dose of 375 mg/m2. Immunomedics' hA20 displays similar binding characteristics and mechanisms of action as rituximab. Constructed using the same human donor frameworks as the Company's anti-CD22 antibody, epratuzumab, hA20 shows an excellent safety and tolerability profile with shorter infusion times (less than 2 hours for the first infusion and under 1 hour for subsequent infusions) compared to rituximab. To-date, no patients have shown an elevated immune response to repeated injections of hA20.

Seventy-eight adult patients with CD20-positive B-cell NHL have now been enrolled in this open-label, multi-center Phase I/II study. hA20 was administered once weekly for four consecutive weeks at 5 dose levels: 80, 120, 200, 375, or 750 mg/m2. Treatment responses from 56 assessable patients (38 with follicular lymphoma and 18 with non-follicular lymphoma) with at least one post-treatment evaluation were reported at the meeting. The overall objective response rate (partial and complete responses) was 45% (25/56), with 20% (11/56) of patients having a complete response (CR/CRu).

In the 38 patients with follicular lymphoma, the overall response rate was 47% (18/38), with a complete response rate of 24% (9/38). In non-follicular lymphomas, the overall responses rate was 39% (7/18), with a complete response rate of 11% (2/18). In a median follow-up of 8 months post therapy, 12/25 (48%) had continuing responses, including 5 with long-lived responses (15-24 months). At the lowest dose of 80 mg/m2, B-cell depletion occurred after the first infusion, and 2 patients had complete response. One in the follicular lymphoma group and the other patient had marginal zone lymphoma. Other data are being evaluated at this low dose with more patients accruing.

This study was extended to focus on confirming the efficacy of lower doses at 80 and 120 mg/m2. The results confirmed that complete responses and B-cell depletion occurred at all five doses.

"We believe the low dose allows us to develop a subcutaneous formulation for hA20 with the goal of offering patients the benefits of ease of use with less side effects," commented Cynthia L. Sullivan, President and CEO of Immunomedics. "While we continue to discuss out-licensing this product with potential partners, we plan to initiate a study in NHL patients with the new subcutaneous formulation and to advance the development of this humanized CD20 antibody in an autoimmune disease using the existing intravenous formulation before the end of this calendar year," She further remarked.

In the United States, NHL is the most common form of blood cancer, affecting over 380,000 people. In 2007, there are approximately 63,190 new cases and almost 18,660 deaths from this disease in the United States.

About hA20

hA20 was constructed using the same human donor frameworks and methods employed to make the Company's anti-CD22 antibody, epratuzumab. Epratuzumab has been studied in over 300 non-Hodgkin's lymphoma (NHL) patients and can be infused within an hour. hA20 displays similar binding avidity, specificity, and mechanisms of action as rituximab, but has structural differences, and to- date shows an excellent safety and tolerability profile, even when infused within 2 hours. At a single low dose of 80 mg/m2, hA20 depleted circulatory B-cells, and when given once weekly for 4 consecutive weeks, produced complete responses in NHL patients. Doses between 80 and 750 mg/m2 were evaluated in this multi-center clinical trial. To-date, no patients have shown an elevated immune response to repeated injections of hA20.

About Immunomedics

Immunomedics is a New Jersey-based biopharmaceutical company 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 have licensed our lead product candidate, epratuzumab, to UCB, S.A. for the treatment of all autoimmune disease indications worldwide. We have retained the rights for epratuzumab in oncology indications for which UCB has been granted a buy-in option. UCB has development, manufacture and commercialization rights, and is responsible for all clinical trials evaluating epratuzumab for the treatment of patients with moderate and severe lupus. At present, there is no cure for lupus and no new lupus drug has been approved in the U.S. in the last 40 years. The Company is conducting clinical trials with hA20 in patients with non-Hodgkin's lymphoma, epratuzumab as a potential therapeutic for patients with lymphoma and leukemia, 90Y-epratuzumab for the therapy of patients with lymphoma, 90Y-hPAM4 for pancreas cancer therapy and hCD74 as a therapy for patients with multiple myeloma. We believe that our portfolio of intellectual property, which includes approximately 108 patents issued in the United States, and more than 250 other issued patents worldwide, protects our product candidates and technologies. We also have a majority ownership in IBC Pharmaceuticals, Inc., which is developing a novel Dock and Lock (DNL) methodology, 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. For additional information on us, please visit our web site at immunomedics. 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 partner for the further development of epratuzumab for autoimmune 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.

Immunomedics, Inc.
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