Immunomedics Offers Results with IMMU-132 in Patients with Pancreatic Cancer

Immunomedics, Inc., IMMU today reported a stabilization of disease, as measured by computed tomography (CT) according to RECIST criteria, in pancreatic cancer patients with advanced disease and who failed 1-5 prior therapies. In a group of 13 CT-assessable patients receiving repeated doses of the Company's investigational antibody-drug conjugate (ADC), IMMU-132, a median time-to-progression of 12.7 weeks was reported (range 4.3-21.4 weeks), which is better than the median 8.0 weeks (range 4-36 weeks) estimated from their last prior therapy. Results from the ongoing Phase I/II study were presented at the American Association for Cancer Research Special Conference on Pancreatic Cancer: Innovations in Research and Treatment by Vincent J. Picozzi Jr., M.D., Director of the Pancreas Center of Excellence at the Virginia Mason Medical Center's Digestive Disease Institute, Seattle, WA. It is known that in such advanced, highly malignant cancers, responses and outcome are poorer with each successive treatment. "This is why we are encouraged that this group of heavily pretreated, advanced pancreatic cancer patients showed a longer period of disease control compared with their most recent therapy before entering this trial," Dr. Picozzi stated. A total of 15 advanced PDC patients who relapsed after a median of 2 prior therapies (range 1-5) have been enrolled in the multicenter trial. One patient was not evaluated due to clinical progression, while another patient's CT assessment is pending. Patients were administered IMMU-132 on days 1 and 8 in repeated 21-day cycles for up to 8 cycles. IMMU-132 consists of the Company's proprietary anti-TROP-2 humanized antibody conjugated with a high number of SN-38 drug molecules by a site-specific linker technology. Preclinical studies have indicated that a significantly higher amount of SN-38, the active metabolite of irinotecan, is delivered to human cancers growing in mice than when high doses of the parent compound, irinotecan, is given. IMMU-132 was well tolerated by patients, with 2 patients having received more than 10 doses. Furthermore, despite multiple administrations, none of the patients developed an antibody response to IMMU-132 or SN-38 to-date. The major toxicities are similar to irinotecan, such as neutropenia and diarrhea, but less severe. "We are encouraged with these early clinical results from IMMU-132 in patients with advanced pancreatic cancer," said Cynthia L. Sullivan, President and Chief Executive Officer. "For future clinical development of this ADC in this indication, we plan to evaluate it in combination with other drugs used earlier in this disease, since these results suggest that IMMU-132 is active in pancreatic cancer," Ms. Sullivan added. The Company will present current Phase I and II results with IMMU-132 in diverse advanced solid cancers at the forthcoming American Society of Clinical Oncology annual meeting, including encouraging partial responses by RECIST criteria in patients with colorectal, triple-negative breast, small-cell and non-small cell lung, and esophageal cancers. This study in pancreatic cancer patients 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.