Immunomedics Announces Durable Responses in Metastatic Lung Cancer Patients Treated With Sacituzumab Govitecan

CHICAGO, June 2, 2015 (GLOBE NEWSWIRE) -- Immunomedics, Inc., (Nasdaq:IMMU) today announced that sacituzumab govitecan, the Company's lead investigational antibody-drug conjugate (ADC), demonstrated in a mid-stage clinical study promising anti-tumor activity in patients with metastatic lung cancer. These patients had either failed to respond to their last cancer therapies or their cancer had returned or progressed.

Lung cancer kills more patients than any other cancers in both men and women, and is the second most commonly diagnosed cancer in the U.S. The disease is classified as small cell (SCLC) or non-small cell (NSCLC) for the purposes of treatment. NSCLC is the most common type of lung cancer, accounting for more than 85% of new diagnoses. Patients with advanced-stage NSCLC are usually treated with chemotherapy, targeted drugs, or some combination of the two.

Forty-seven patients with metastatic lung cancer (25 NSCLC, 22 SCLC) have been enrolled into this multicenter study. Treatment response from these patients was assessed by computed tomography using the rules set by the Response Evaluation Criteria In Solid Tumors (RECIST 1.1).

In this study, treatment with sacituzumab govitecan produced tumor shrinkage of 30% or more in 6 of 19 patients with advanced NSCLC, or 32%. The disease control rate, which includes patients with treatment response within the range of 30% tumor shrinkage and 20% tumor growth, was 74%. An interim analysis of the length of time patients were living without their cancer progressing showed a median of 5.4 months, with 44% of patients still enjoying this survival benefit.

SCLC, which accounts for 13% of new cases of lung cancer, is the more aggressive form. Treatment options for SCLC are more limited, usually involve chemotherapy alone or combined with radiation. According to the National Cancer Institute, from 1999-2006, only 2.7% of patients diagnosed with metastatic SCLC survived for more than 5 years, which was lower than the survival rate of 3.7% for patients with metastatic NSCLC.

Despite the aggressive nature of the disease, 30% of 20 patients with advanced SCLC responded to sacituzumab govitecan treatments with 30% or more tumor reduction. The disease control rate in this group of lung cancer patients was 55%. With 70% of patients having had their disease progressed, the interim progression-free survival is currently at 2.4 months.

Commenting on these results presented in an Oral Abstract Session at the 2015 Annual meeting of the American Society of Clinical Oncology, Dr. Michael J. Guarino of the Helen F. Graham Cancer Center & Research Institute, Newark, DE, remarked, "These efficacy results are very promising in a challenging disease, such as advanced lung cancer, with duration of response particularly worth noting."

For the 25 patients who responded to sacituzumab govitecan, all 11 SCLC patients and 12 of 14 NSCLC patients, or 86%, had a time to progression that was longer than their last therapy. These patients had previously failed a median of 2.5 (range 1-7) and 3 (range 1-8) cancer treatments, respectively.

Sacituzumab govitecan has a tolerable safety profile in these heavily-pretreated lung cancer patients at the optimal doses of 8 and 10 mg/kg, as has been reported by the Company in triple-negative breast and gastrointestinal cancers, with 18% Grades 3 and 4 neutropenia as the major toxicity and minimal Grade 3 diarrhea (7%).

"We believe these findings are compelling enough for us to consider lung cancer as another oncology indication, in addition to triple-negative breast cancer (TNBC), for further development and commercialization of sacituzumab govitecan," commented Cynthia L. Sullivan, President and Chief Executive Officer of Immunomedics. "This agent has Fast Track status from FDA for treating patients with advanced, refractory TNBC, NSCLC, and SCLC," she added.

Sacituzumab govitecan is a first-in-class antibody-drug conjugate (ADC) developed by the Company by conjugating the moderately-toxic drug, SN-38, site-specifically and at a high ratio of drug to antibody to a humanized antibody that targets the TROP-2 receptor expressed by many solid cancers. SN-38 is the active metabolite of irinotecan (Camptosar), which is used to treat certain solid cancers, particularly metastatic colorectal cancers, as a part of combination therapies, so its pharmacology and properties are well-known.

Dr. Gregory A. Masters, a colleague of Dr. Guarino at Helen F. Graham Cancer Center & Research Institute also participated in this multicenter study. Other Principal Investigators include Dr. Alexander N. Starodub, Indiana University Health Center for Cancer Care, Goshen, IN; Drs. Rebecca Heist and Aditya Bardia, Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA; Dr. Wells A. Messersmith, University of Colorado Cancer Center, Aurora, CO; Dr. Allyson J. Ocean, Weill Cornell Medical College, New York, NY; and Dr. Sajeve S. Thomas, UF Health Cancer Center, Orlando, FL.

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 nine clinical-stage product candidates. Immunomedics has an ongoing collaboration with UCB, S.A. (UCB), to whom the Company licensed epratuzumab for the treatment of all non-cancer indications worldwide. UCB expects Phase 3 data in systemic lupus erythematosus in the first half of 2015. Immunomedics is exploring epratuzumab in oncology in collaboration with independent cancer study groups. Immunomedics' most advanced candidate to which it retains worldwide rights for all indications is 90Y-clivatuzumab tetraxetan. The Company initiated a Phase 3 registration trial in January 2014 in patients with advanced pancreatic cancer and expects patient enrollment to be completed in calendar year 2016. Immunomedics' portfolio of wholly owned product candidates also 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. 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 pre-clinical development. These include 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 267 active patents in the United States and more than 400 foreign patents, protects its product candidates and technologies. Immunomedics' strength in intellectual property has resulted in a top-8 ranking in the Biotechnology industry by the Patent Board for the 2014 fiscal year. For additional information on the Company, please visit its website at The information on its 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, 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, risks associated with the outcome of pending litigation and 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: For More Information: Dr. Chau Cheng Senior Director, Investor Relations & Corporate Secretary (973) 605-8200, extension 123 ccheng@immunomedics.comSource:Immunomedics, Inc.