Immunomedics Announces Multiple Objective Responses in Solid Cancers with IMMU-132, Trial Expanding to Phase 2

Immunomedics, Inc.

, 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 its newest antibody-drug conjugate (ADC), IMMU-132, has produced durable partial responses in three different cancer types in early phase of clinical evaluation. Results from the multicenter, dose-escalation Phase I trial were presented by Dr. Alexander N. Starodub of the Indiana University Health Goshen Center for Cancer Care, Goshen, IN, at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in Boston, Massachusetts. In addition to the 3 partial responses observed by computed tomography (CT) using RECIST criteria, 15 patients also reported stable disease as their best response for an overall disease control rate of 86% in 21 patients with at least 1 CT assessment reported at the Conference. In terms of CT-confirmed tumor shrinkage, about half of the patients showed this result. "We, as well as our clinical investigators, are very encouraged by these early promising results with IMMU-132 in this refractory, advanced cancer patient population with difficult-to-treat tumors that failed multiple prior therapies," commented Cynthia L. Sullivan, President and Chief Executive Officer of Immunomedics. "This is the first time these results have been presented at a scientific meeting after peer-review of the submitted abstract. The study has now transitioned to Phase II for additional safety and efficacy data in patients with certain tumor types using doses that were found active and tolerable in Phase I," Ms. Sullivan added. At the time of reporting, a total of 25 patients with 12 different types of epithelial cancers have been enrolled into the Phase I trial. These patients had failed a median of 3 (range 1-6) prior standard therapies for their tumor types and were enrolled with disease progression. IMMU-132 was administered weekly for 2 consecutive weeks, followed by one week off, in 3-week cycles. Treatments may continue for up to 8 cycles until unacceptable toxicity or progression of disease. Currently, 10 patients are continuing treatments. The major side-effects of IMMU-132 are neutropenia and controllable diarrhea, consistent with the toxicity experienced with irinotecan, the parent drug of SN-38, despite this agent releasing about 20-fold more SN-38 than when irinotecan is given. This study was supported in part by Award Number R43CA171388 from the National Cancer Institute. The content is solely the responsibility of the Company and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health.