Phase II Study Presented by Cancer and Leukemia Group B (CALGB) at 52nd Annual Meeting of American Society of Hematology (ASH)

ORLANDO, FL, USA | December 6, 2010 | 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 announced that combination therapy with epratuzumab and rituximab was effective, with durable complete responses in one-third of evaluable patients, and was very well tolerated by patients with previously untreated follicular lymphoma (FL).

Epratuzumab is Immunomedics’ proprietary humanized anti-CD22 monoclonal antibody that has shown single agent activity in FL, and when used in combination with rituximab, produced durable, complete responses in patients with relapsed or refractory indolent non-Hodgkin’s lymphoma (NHL). Rituximab is also effective as single agent therapy for FL, and has extended remissions and survival when combined with chemotherapy. The goal of this multicenter, open-label, Phase II trial was to evaluate the combination of epratuzumab and rituximab without chemotherapy in treatment-naive FL patients.

Sixty evaluable FL patients were enrolled by the NCI-sponsored study group, CALGB, to receive intravenous epratuzumab and rituximab at 360 mg/m2 and 375 mg/m2, respectively. Rituximab was administered weekly for 4 weeks, then every 8 weeks for 4 additional doses for a total of 8 doses over 9 months. Epratuzumab was given two days before the first rituximab dose to assess toxicity. From week 2 on, epratuzumab was given before rituximab on the same day for a total of 8 doses over 9 months.

Patients were categorized into three groups with good, intermediate or poor prognosis, based on their Follicular Lymphoma International Prognostic Index (FLIPI) scores. A high FLIPI score predicts a patient having a poorer chance of having a treatment response. FLIPI scores at study entry were 13 (22%) low; 28 (47.5%) intermediate; and 18 (30.5%) high.

Results from 57 evaluable patients were reported at the meeting. Overall, the two antibodies produced an objective response rate of 84.2% with 20 complete responses (CRs) (33.3%), 30 partial responses (PRs) (50.9%) and 8 patients (13.6%) having stable disease. The mean time to CR was 9 months. Four patients progressed after a period of stable disease, and 23 of the 30 patients who achieved PR remain in response. All 20 CRs also remain in remission at the time of reporting, with a median follow-up of 1.4 years. The CR rate in low risk patients was 31%, 44% in intermediate risk and 18% in high risk patients.

"This is the 4th multicenter trial indicating high efficacy of epratuzumab when combined with rituximab," commented Cynthia L. Sullivan, President and Chief Executive Officer of Immunomedics, Inc.

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, 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 www.immunomedics.com.

SOURCE: Immunomedics, Inc.