Immunomedics Announces Multiple Partial Responses With IMMU-132 in Solid Cancers

SAN DIEGO, April 7, 2014 (GLOBE NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), 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 5 patients reported a partial response as their best response, based on RECIST 1.1 criteria, in the Company's ongoing Phase I/II clinical trial of its investigational antibody-drug conjugate (ADC), IMMU-132, in patients with solid cancers. IMMU-132 is an anti-TROP-2 antibody with SN-38, the active metabolite of irinotecan, linked to the antibody.

Results from this multicenter study, as well as initial data from the expansion phase of the trial, were presented by Dr. Alexander Starodub of Indiana University Health Goshen Center for Cancer Care, Goshen, IN, at the 2014 Annual Meeting of the American Association for Cancer Research (AACR) in San Diego, CA.

Two of the 3 patients with small-cell lung cancer (SCLC), 2 of the seven patients with triple- negative breast cancer, and 1 of the 11 patients with colorectal cancer were partial responders by at least one computer tomography (CT) assessment. In addition to these 5 partial responses, among the 35 patients who had at least one response assessment by CT, 22 patients had stable disease as their best response, giving an overall disease control rate of 77%. Besides colorectal, triple-negative breast, and SCLC, the 35 CT-assessable patients include 14 other types of solid cancer. These patients had failed a median of 4 prior treatments, some including topoisomerase-I and -II inhibiting drugs, and in some cases are showing durable responses up to almost one year.

Grade 3 or 4 adverse events (AE) ≥ 8 % were neutropenia (31%), fatigue (10%), and diarrhea (8%), while mild AE ( > 20%) were reported for nausea, fatigue, alopecia, diarrhea and vomiting.

IMMU-132 was administered once weekly for two weeks followed by one week of rest in a 3-week cycle. Despite repeated dosing, no antibodies against the ADC, either to the antibody or to the SN-38, have been detected. The conjugate clears completely within 7 days, which is consistent with our preclinical studies showing 50% of the SN-38 is released in the serum every day.

Dr. Starodub commented, "Our experience in the IMMU-132 trial has shown promising efficacy results with a manageable and acceptable safety profile in multiple patient populations, including those with limited therapy options, such as triple-negative breast cancer and small-cell lung cancer."

"IMMU-132 continues to produce encouraging results as more patients with advanced solid cancers are enrolled into our expansion trial," said Cynthia L. Sullivan, President and Chief Executive Officer. "We believe this SN-38-containing ADC that targets the TROP-2 antigen has the potential to be a novel platform technology for the therapy of diverse metastatic solid cancers," she added.

Results from 13 pancreatic cancer patients with CT-assessments also showed a high disease control rate, but are not included in this report because they will be presented at the upcoming AACR Special Conference on Pancreatic Cancer in May, 2014.

The pancreatic cancer patient part of the 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.

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. Our lead product candidate, epratuzumab, is currently in two Phase III clinical trials in lupus. In oncology, clivatuzumab tetraxetan labeled with a radioisotope is in a Phase III pivotal trial in advanced pancreatic cancer patients. Other solid tumor therapeutics in Phase II clinical development include 2 antibody-drug conjugates, IMMU-132 (anti-TROP-2-SN-38) and IMMU-130 (anti-CEACAM5-SN-38). We also have a majority ownership in IBC Pharmaceuticals, Inc., which is developing a novel DOCK-AND-LOCK™ (DNL™) method with us for making fusion proteins and multifunctional antibodies. DNL™ is being used particularly to make bispecific antibodies targeting cancers and infectious diseases as a T-cell redirecting immunotherapy, as well as bispecific antibodies for next-generation cancer and autoimmune disease therapies. We believe that our portfolio of intellectual property, which includes approximately 245 active patents in the United States and more than 400 foreign patents, protects our product candidates and technologies. Our strength in intellectual property has resulted in the top-4 ranking in the January 2014 Patent Board scorecard in the Biotechnology industry. For additional information on us, please visit our website at 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 (including the funding therefor, outcomes, timing or associated costs), out-licensing arrangements (including the timing and amount of contingent payments), forecasts of future operating results, potential collaborations, 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 any cash payment that the Company might receive in connection with a sublicense involving a third party and UCB, which is not within the Company's control, new product development (including clinical trials outcome and regulatory requirements/actions), our dependence on UCB for the further development of epratuzumab 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.

CONTACT: Dr. Chau Cheng Senior Director, Investor Relations & Grant Management (973) 605-8200, extension 123 ccheng@immunomedics.comSource:Immunomedics, Inc.