Immunomedics Announces New U.S. Patent for Sacituzumab Govitecan (Immu-132) Antibody-Drug Conjugate (ADC)

MORRIS PLAINS, N.J., June 28, 2016 (GLOBE NEWSWIRE) -- Immunomedics, Inc., (Nasdaq:IMMU) today announced the issuance of U.S. Patent 9,375,489, entitled “Antibody-SN-38 Immunoconjugates with a CL2A Linker.” This is the 28th issued U.S. patent covering the composition and uses of sacituzumab govitecan (IMMU-132), the Company’s lead cancer therapeutic. Sacituzumab govitecan is an antibody-drug conjugate (ADC) comprising a humanized antibody to the cancer marker, Trop-2, conjugated with SN-38, the active metabolite of the well-known anticancer drug, irinotecan. This ADC is in development for the treatment of patients with many diverse solid cancers, with initial results reported at various meetings and in Clinical Cancer Research.1 The most advanced indication in development is triple-negative breast cancer (TNBC), with Phase 2 studies also continuing in patients with metastatic non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC),2,3 and in patients with metastatic urothelial cancers.4

This most recent patent expires in 2029, but other patents covering this product and technology have expiration dates to 2033. The diverse patents have claims for composition of matter, including the antibody and linker molecule, increased number of drugs per antibody, uses in various cancers, including different dose schedules, and other proprietary features of the ADC.

Cynthia L. Sullivan, President and Chief Executive Officer, commented: “This extensive patent coverage complements the 12-year biotechnology exclusivity in the U.S. for such products, we believe, and enhances this agent’s potential commercial value.” “We have also received claims in many of these patents in other countries, and continue to prosecute additional patent applications for our ADC platform technology worldwide,” Ms. Sullivan added.

Sacituzumab Govitecan Development Plan
The Company also related its updated clinical development plan for sacituzumab govitecan in TNBC, based on a recent Breakthrough Therapy Designation (BTD) and a follow-on meeting with the U.S. Food and Drug Administration (FDA).

In the fall of this year, the Company plans to complete enrolling additional patients with relapsed/refractory metastatic TNBC who have received at least two prior therapies, including taxane, for metastatic disease into the ongoing single-arm Phase 2 study. Results from this Phase 2 study are expected to support the clinical requirements for pursuing Accelerated Approval. All patients receive repeated cycles of sacituzumab govitecan at the dose of 10 mg/kg on days 1 and 8 of a twenty-one day cycle. Treatment responses, including overall response rate and duration of response, are assessed with computed tomography (CT) in accordance with RECIST 1.1, and confirmed by an independent centralized and blinded group of radiology experts.

The Company is working with the FDA on these plans for completing the ongoing Phase 2 trial and for submitting an Accelerated Approval registration application, based on interactions with the agency. Furthermore, initial discussion has also occurred with the European Medicine Agency (EMA), which has provided the Company with advice on its planned Phase 3 trial.

“This enrollment timeline will allow us to have at least six months of patient follow-up to obtain a confirmed response rate and a mature duration of response, which will be part of an Accelerated Approval application estimated to be submitted to the regulatory agency by the middle of calendar year 2017,” noted William A. Wegener, M.D., Ph.D., Chief Medical Officer of Immunomedics. “It will also allow us to have our Phase 3 trial, which we have reached agreement with FDA on a Special Protocol Assessment (SPA), well underway, as required by the FDA for Accelerated Approval. Our goal is to make IMMU-132 available to metastatic TNBC patients as quickly as possible, given what we believe is the first time the FDA has granted a BTD in this indication,” he further remarked.

“Preparation for the commercial-scale manufacturing of the ADC using three outside contract manufacturing organizations (CMOs) is proceeding according to plan and the Company hopes to begin the Phase 3 study, with drug supplied by our CMOs, in December 2016,” Ms. Sullivan explained.

“To fund the Phase 3 confirmatory study and further clinical development of this important and valuable asset in other solid cancers, we continue to work with our outside advisory group, which we retained the beginning of this year, to assist us in bringing a licensing arrangement with a global corporate partner to completion,” Ms. Sullivan concluded.


  1. Starodub AN, Ocean AJ, Shah MA, et al. First-in-Human Trial of a Novel Anti-Trop-2 Antibody-SN-38 Conjugate, Sacituzumab Govitecan, for the Treatment of Diverse Metastatic Solid Tumors. Clin Cancer Res; 21(17); 3870–8; 2015.

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 FDA for the treatment of patients with triple-negative breast cancer who have failed at least 2 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 288 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 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, anticipated patient enrollment, trial outcomes, timing or associated costs), regulatory timelines, 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), the Company’s dependence on business collaborations in order to further develop our products and finance our operations, the risk that we or any of our collaborators may be unable to secure regulatory approval of and market our drug candidates, 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.

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