Immunomedics, Inc. Release: Promising Results with Epratuzumab and Chemotherapy in Children with Acute Lymphoblastic Leukemia

CHICAGO, June 4 /PRNewswire-FirstCall/ -- Immunomedics, Inc. , a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced that treatment with epratuzumab plus standard chemotherapy is feasible and well tolerated in children with B-precursor acute lymphoblastic leukemia (ALL), producing favorable early responses in the majority of patients. Elizabeth Raetz, MD, pediatric oncologist at New York University, New York, in an oral presentation at the 43rd Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago, IL, reported results from this multicenter feasibility/phase II study.

Fifteen patients with CD22-positive ALL in marrow relapse were enrolled in the feasibility portion of the study. Nine patients were in first and 3 in second or later marrow relapse. Epratuzumab was given alone at 360 mg/m2 twice weekly for two weeks followed by 4 weekly doses of epratuzumab in combination of standard cytotoxic chemotherapy. Within 24 hours of the 6-week treatment period, surface CD22 antigen was not detected on peripheral blood leukemic blasts in all but one of the 12 assessable patients, indicating effective targeting of leukemic cells by epratuzumab. At the time of reporting, 9/12 patients (75%) achieved a complete remission, of whom 7 showed no residual disease by flow cytometry; 1 patient had a partial response, 1 stable disease, and 1 with disease progression.

“We are encouraged by these results. The phase-2 portion of the study is now opened for enrollment of 112 patients, with a primary endpoint of second complete remission rate,” commented Dr. Raetz, the study chair.

“We are pleased that COG shares our enthusiasm for epratuzumab and has chosen to evaluate our antibody in their ongoing search for new treatments for childhood leukemia. We will continue to expand the application of epratuzumab to other B-cell malignancies,” remarked Ms. Cynthia L. Sullivan, Immunomedics’ President and Chief Executive Officer.

The most common toxicities were grade-1/2 infusion reactions, which occurred during the initial infusions only. Two non-hematological dose-limiting toxicities occurred. One patient had a grade-4 seizure of unclear etiology and one patient had asymptomatic grade-3 transaminase elevation that returned to baseline prior to the time for the next treatment cycle. All patients were able to resume infusions at a slower rate after additional premedication.

About Acute Lymphoblastic Leukemia (ALL)

According to the American Cancer Society, an estimate of 2,790 children before age 20, which represents 23% of new cases, will be diagnosed with ALL in the United States in 2007 making ALL the most common cancer in children and adolescents. About 85% of ALL is B-cell ALL, and the most common subtype of B-cell ALL is B-precursor ALL. CD22 is expressed in more than 90% of childhood B-precursor ALL. Although the 5-year survival rate for ALL in children is 87%, the prognosis for a child with relapsed ALL remains poor.

About Children’s Oncology Group

The Children’s Oncology Group (COG) is a network of more than 5,000 doctors, nurses and scientists who conduct clinical trials and perform cutting-edge research to cure childhood cancer at more than 200 COG member institutions. COG represents every pediatric cancer program in North America, providing state-of-the-art medical and nursing care to more than 90% of children with cancer.

The multicenter feasibility/phase II study reported by Elizabeth Raetz, MD, pediatric oncologist at New York University, New York, was supported by grant CA-98543 from the National Cancer Institute and the Jeffrey Pryde Foundation for Leukemia Research.

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 http://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 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.

For More Information: Dr. Chau Cheng Associate Director, Investor Relations & Business Analysis (973) 605-8200, extension 123 ccheng@immunomedics.com

Immunomedics, Inc.

CONTACT: Dr. Chau Cheng, Associate Director, Investor Relations & BusinessAnalysis, Immunomedics, Inc., +1-973-605-8200, ext 123, orccheng@immunomedics.com

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