SAN FRANCISCO, CA, USAI January 20, 2015 I Immunomedics, Inc., (IMMU) today announced that sacituzumab govitecan, the Company’s lead investigational antibody-drug conjugate (ADC), produces partial response (PR) in some patients with metastatic esophageal and colorectal cancers who had been heavily pretreated. Extended periods of stable disease were also noted in some patients with pancreatic and gastric cancers, with time-to-progression (TTP) exceeding that of last prior therapy in many cases. Response and TTP were evaluated by computed tomography (CT) based on RECIST criteria.
Patented and developed by the Company, sacituzumab govitecan was created 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. Alexander N. Starodub of Indiana University Health Center for Cancer Care, Goshen, IN, presented the Phase 1/2 study at the 2015 Gastrointestinal Cancers Symposium co-sponsored by the American Gastroenterological Association (AGA), the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO), and the Society of Surgical Oncology (SSO) in San Francisco, CA.
A total of 63 patients with various types of gastrointestinal cancers had been enrolled into this multicenter study. At the time of analysis, 26 patients with colorectal cancer, 13 with esophageal cancer, 3 with gastric cancer and 14 with pancreatic cancer were evaluated by CT for response and TTP. Median numbers of prior treatments ranged from 2 for pancreatic cancer to 4 in colorectal cancer.
Despite the late-stage setting, 1 patient in each of the colorectal and esophageal cancer groups had a partial response after receiving more than 2 doses of the ADC. For all 4 cancer types, the disease stabilization rate (partial response + stable disease) exceeded 50%.
Colorectal | Esophageal | Gastric | Pancreatic | |||||
Number of Patients Enrolled | 29 | 14 | 5 | 15 | ||||
Median No. Prior Treatments (Range) | 4 (1-7) | 3 (2-6) | (1-4) | 2 (1-5) | ||||
Response Assessment* | 26 | 13 | 3 | 14 | ||||
Partial Response | 1 (4%) | 1 (8%) | 0 | 0 | ||||
Stable Disease | 14 (54%) | 6 (46%) | 3 (100%) | 8 (57%) | ||||
* Response assessments based on patients who received more than 2 treatment doses of 8, 10 or 12 mg/kg. |
Commenting on these results, Cynthia L. Sullivan, President and Chief Executive Officer, stated, “This novel ADC is encouraging as a monotherapy, as demonstrated in this trial. We have also conducted additional preclinical testing that indicates it is suitable for combination therapy in these gastrointestinal cancers.”
Repeated cycles of therapy with sacituzumab govitecan over many months were well tolerated by patients and did not produce the typical side effects of irinotecan treatment other than neutropenia. Transient neutropenia was the major toxicity (18% Grade 3 and 6% Grade 4), followed by febrile neutropenia 4%, and diarrhea 3% Grade 3.
In addition to Dr. Starodub of Indiana University Health Center for Cancer Care, the multicenter study also involved Drs. Allyson J. Ocean and Manish A. Shah, Weill Cornell Medical College, New York, NY; Dr. Wells A. Messersmith, University of Colorado Cancer Center, Aurora, CO; Dr. Vincent J. Picozzi, Virginia Mason Cancer Center, Seattle, WA; Dr. Michael J. Guarino, Helen F. Graham Cancer Center & Research Institute, Newark, DE; Dr. Sajeve S. Thomas, UF Health Cancer Center-Orlando Health, Orlando, FL; and Dr. Aditya Bardia, Massachusetts General Hospital Cancer Center, Termeer Center for Targeted Therapies, Boston, MA.
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 indicationsis 90Y-clivatuzumab tetraxetan. The Company initiated a Phase 3 registration trial in January 2014 in patients with advanced pancreatic cancer and expects topline data in mid-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(R) protein conjugation technology. The Company believes that its portfolio of intellectual property, which includes approximately 262 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 www.immunomedics.com. The information on its website does not, however, form a part of this press release.
SOURCE: Immunomedics