Celsion Corporation Announces ASCO 2015 GEN-1 Immunotherapy Phase 1b Results in Ovarian Cancer Presentation

Celsion Corporation

, a fully integrated oncology drug development company, today announced that results from its Phase Ib trial for GEN-1 in platinum-resistant ovarian cancer will be presented in poster session at the 2015 American Society of Clinical Oncology (ASCO) meeting in Chicago on Saturday, May 30th. GEN-1 is an IL-12 DNA plasmid vector encased in a nanoparticle delivery system, which enables cell transfection followed by persistent, local secretion of the IL-12 protein. Dr. Premal H. Thaker, M.D., associate professor at Washington University and Siteman Cancer Center in St. Louis and a principal investigator for the study, highlighted the results in an abstract titled, "A Phase I Study of Intraperitoneal EGEN-001 (IL-12 Plasmid Formulated with PEG-PEI-Cholesterol Lipopolymer) Administered in Combination with Pegylated Liposomal Doxorubicin) in Patients with Recurrent or Persistent Epithelial Ovarian, Fallopian Tube or Primary Peritoneal Cancer." The abstract is available on the ASCO website. The Phase 1b dose escalating study enrolled 16 patients with platinum-resistant ovarian cancer and evaluated the safety, tolerability and efficacy of GEN-1 in combination with pegylated doxorubicin as well as the effect of intraperitoneal injection of GEN-1 on IL-12 and tumor cytokine levels. Patients received pegylated liposomal doxorubicin on day 1 and GEN-1 on days 1, 8, 15 and 22. This treatment regimen was repeated every 28 days in the absence of disease progression or unacceptable toxicity. The findings demonstrated an overall clinical benefit of 57% for all treatment arms, with a partial response (PR) rate of 21% and a stable disease (SD) rate of 36%. The overall clinical benefit observed at the highest dose level was 86% (PR=29%, SD=57%). GEN-1 was well tolerated, with no dose limiting toxicities and no overlapping toxicities between GEN-1, its subsequent immune system activation and pegylated doxorubicin. "These clinical results are very encouraging, especially given the fact that patients suffering from advanced relapsed ovarian cancer have typically failed previous treatments and have limited treatment options for this aggressive cancer. GEN-1 is a novel immunotherapy designed to enhance the patient's immune system to help the body treat and fight cancer," said Dr. Thaker. "I am pleased to be part of this important study and look forward to continuing my involvement with future trials of GEN-1 IL-12 immunotherapy in this underserved patient population." Additional translational data measuring cytokine levels (IFN-gamma and TNF-alpha) at increased doses of GEN-1 is expected to be presented during the ASCO meeting. Since the maximum tolerated dose was not reached in this study, Celsion plans to expand its ovarian cancer development program to include two Phase 1 dose escalating trials evaluating GEN-1 in first line neoadjuvant ovarian cancer and in combination with Avastin® and Doxil® in platinum-resistant ovarian cancer. "These data, particularly the overwhelmingly positive response rate seen at the highest dose level for GEN-1, are extremely impressive and underscore the potential clinical utility of this immunotherapy in ovarian cancer," said Michael H. Tardugno, Celsion's chairman, president and chief executive officer. "In the second half of 2015, we plan to begin a Phase 1b study evaluating GEN-1 at higher doses in first-line neoadjuvant ovarian cancer. Based on compelling preclinical combination data, we also plan to initiate a Phase 1 dose escalating trial evaluating GEN-1 plus Avastin® and Doxil® in platinum-resistant ovarian cancer patients, a combination which has the potential to significantly improve treatment outcomes for these patients."