— Preclinical Studies Presented at 2016 San Antonio Breast Cancer Symposium (SABCS) —
— Updated Phase 2 Results with Sacituzumab Govitecan (IMMU-132) in Metastatic Triple-Negative Breast Cancer also Reported —
— Full Results with IMMU-132 will be Available in a Journal Publication —

SAN ANTONIO, TX, USA I December 12, 2016 I  Immunomedics, Inc. (IMMU) today announced a novel immuno-oncology agent, (E1)-3s, that can direct a patient’s T cells, a type of white blood cells, to kill cancer cells with the cancer marker, the Trop-2 antigen, which can be enhanced by combining with an immune checkpoint inhibitor.

Cynthia L. Sullivan, President and Chief Executive Officer, said, “The potent activity shown by (E1)-3s in this preclinical study and the prevalence of Trop-2 expression in triple-negative breast cancer (TNBC) make it an attractive candidate for T-cell redirected therapy of breast cancer. Combining immune checkpoint inhibitors with redirected T-cell therapy may represent a new paradigm for the management of solid cancers, including breast, and is worthy of further investigation.”

Ms. Sullivan added, “We believe there is a significant need for the patient treatments we are developing, which underscore the value creation opportunities available to Immunomedics’ stockholders through our robust pipeline. Our advancements in TNBC highlight the positive progress we are making on our near-term milestones and the ability of our team to successfully deliver on these objectives.”

Trop-2 is a receptor found on many solid cancers and the target of the Company’s lead antibody-drug conjugate, sacituzumab govitecan (IMMU-132). In a single-arm Phase 2 study, IMMU-132 has produced promising results in patients with diverse late-stage metastatic disease, including TNBC, small-cell and non-small-cell lung, and urothelial cancers. Encouraged by these results, the Company is interested in advancing its existing, strong pipeline and developing another treatment modality for these and other Trop-2-expressing cancers.

(E1)-3s is a bispecific antibody created with the Company’s proprietary Dock-and-Lock® (DNL®) protein conjugation platform technology. In addition to targeting Trop-2, (E1)-3s also binds to the CD3 receptor on T cells. The idea behind this approach is that the bispecific antibody can capture the key T cells in a patient and redirect them to the cancer cells. At the 2016 SABCS, the Company presented a preclinical study on redirected T-cell therapy of TNBC with (E1)-3s.

In a mouse model of human TNBC, compared to an untreated control tumor group, mice given the (E1)-3s bispecific antibody had significantly smaller tumors and an improved median survival time. This study also evaluated the effect of adding an immune checkpoint inhibitor, an anti-PD-1 antibody developed by the Company, to the redirected T-cell therapy with (E1)-3s. Mice given the combination had significantly smaller tumors and longer median survival time, compared to those treated with (E1)-3s alone. Treatment with the immune checkpoint inhibitor alone did not retard tumor growth or improve survival, compared to the untreated control group.

At the 2016 SABCS meeting, the Company also described a new approach in cancer immunotherapy by genetically engineered a human natural killer (NK) cell line, another type of white blood cell, to recognize the Trop-2 antigen. The result is a chimeric antigen receptor (CAR)-engineered NK cell, designated as E1.BB.3z-92MI, that is significantly more toxic to a human breast cancer cell line in vitro than controls, and has the potential to treat diverse Trop-2-expressing breast, lung, bladder, ovarian, and other cancers. The importance of this work is the potential to have an “off-the-shelf” NK cell population that can be engineered to target to Trop-2 or any cancer target desired.

The Company’s innovative immuno-oncology program was recently honored by the Research and Development Council of New Jersey as the 2016 winner of the prestigious Thomas Edison Patent Award in the Biotechnology category.

In another poster presentation, the lead author of the Phase 2 study with IMMU-132, Aditya Bardia, MD, MPH, Attending Physician at the Massachusetts General Hospital Cancer Center, Harvard Medical School, in Boston, MA, reported updated results in patients with metastatic TNBC. The results of this expansion trial confirmed prior objective responses (complete and partial remissions), duration of responses, and improved overall survival. Full results have been submitted for publication in a peer-reviewed medical journal. In compliance with the embargo policy of the journal, the Company will discuss the full results in a separate press release at the time of publication.

As previously announced, Immunomedics is focused on achieving near-term milestones that include:

  • Completing the enrollment of 100 TNBC patients into the ongoing Phase 2 clinical trial of IMMU-132 by year-end 2016;
  • Beginning the confirmatory Phase 3 clinical trial of IMMU-132;
  • Submitting a Biological License Application (BLA) to the FDA for accelerated approval for IMMU-132 for patients with metastatic TNBC in mid-2017;
  • Presenting interim results of Phase 2 clinical trials for patients with urothelial cancer at a symposium on genitourinary cancers to be held in early 2017; and
  • Executing on licensing and other strategic activities with regard to IMMU-132 and other clinical and preclinical pipeline drug development candidates as well as platform technologies with the support of Greenhill & Co. as financial advisor.

About Immunomedics
Immunomedics is a clinical-stage biopharmaceutical company developing monoclonal antibody-based products for the targeted treatment of cancer, autoimmune disorders and other serious diseases. Immunomedics’ advanced proprietary technologies allow the Company to create humanized antibodies that can be used either alone in unlabeled or “naked” form, or conjugated with radioactive isotopes, chemotherapeutics, cytokines or toxins. Using these technologies, Immunomedics has built a pipeline of eight clinical-stage product candidates. Immunomedics’ portfolio of investigational products includes antibody-drug conjugates (ADCs) that are designed to deliver a specific payload of a chemotherapeutic directly to the tumor while reducing overall toxic effects that are usually found with conventional administration of these chemotherapeutic agents. Immunomedics’ most advanced ADCs are sacituzumab govitecan (IMMU-132) and labetuzumab govitecan (IMMU-130), which are in Phase 2 trials for a number of solid tumors and metastatic colorectal cancer, respectively. IMMU-132 has received Breakthrough Therapy Designation from the FDA for the treatment of patients with triple-negative breast cancer who have failed at least two prior therapies for metastatic disease. Immunomedics has a research collaboration with Bayer to study epratuzumab as a thorium-227-labeled antibody. Immunomedics has other ongoing collaborations in oncology with independent cancer study groups. The IntreALL Inter-European study group is conducting a large, randomized Phase 3 trial combining epratuzumab with chemotherapy in children with relapsed acute lymphoblastic leukemia at clinical sites in Australia, Europe, and Israel. Immunomedics also has a number of other product candidates that target solid tumors and hematologic malignancies, as well as other diseases, in various stages of clinical and preclinical development. These include combination therapies involving its antibody-drug conjugates, bispecific antibodies targeting cancers and infectious diseases as T-cell redirecting immunotherapies, as well as bispecific antibodies for next-generation cancer and autoimmune disease therapies, created using its patented DOCK-AND-LOCK® protein conjugation technology. The Company believes that its portfolio of intellectual property, which includes approximately 302 active patents in the United States and more than 400 foreign patents, protects its product candidates and technologies. For additional information on the Company, please visit its website at www.immunomedics.com. The information on its website does not, however, form a part of this press release.

SOURCE: Immunomedics