PLYMOUTH MEETING, Pa., Nov. 14, 2016 (GLOBE NEWSWIRE) -- Inovio Pharmaceuticals, Inc. (NASDAQ:INO), today announced an interim data analysis showing that its INO-3112 cancer immunotherapy product generated antigen-specific CD8+ killer T cell responses measured both in tumor tissue and in peripheral blood from subjects with head and neck cancer associated with human papillomavirus (HPV). The immunology results show that INO-3112 treatment generated robust HPV16/18 specific CD8+ T cell responses in peripheral blood in four of five subjects who also showed increased T cell activation in resected tumor tissue samples. These four subjects remained disease free in continuing follow-up that ranged from nine to 24 months at the time of analysis. One subject with only minimal increases in T cell immune responses developed progressive disease at 11 months post start of the study. These results were presented November 12 th at the 2016 Annual Meeting of the Society for Immunotherapy of Cancer (SITC) in National Harbor, Maryland. Dr. J. Joseph Kim, Inovio's President and CEO, said, "In immuno-oncology, it's all about the T cells. We now have evidence in cancer patients that our immunotherapy product can generate antigen-specific CD8+ killer T cell responses in the tumor, a major step forward towards an effective immunotherapy. This study gives us an important opportunity to evaluate a novel treatment approach using a DNA vaccine platform to increase immune activation by generating a robust in-vivo T cell response, especially in the tumor, and potentially decreasing tumor recurrence in HPV positive head and neck cancer patients." INO-3112, an active immunotherapy targeting HPV 16/18 combined with a DNA plasmid for IL-12 as an immune activator, is designed to activate patients' immune responses to specifically target and kill HPV associated tumors. This open label phase I/IIa study has fully enrolled twenty-two subjects with HPV-positive head and neck squamous cell carcinoma and is intended to assess the safety, tolerability, and immunogenicity of INO-3112 in two treatment groups. Additionally, the study is evaluating the anti-tumor response and progression free survival of patients. The first group enrolled six subjects who were treated with INO-3112 before and after resection of their tumor. One subject withdrew consent after surgery, leaving five evaluable subjects in this group. All of these subjects received one dose of INO-3112 (averaging 14 days and ranging 7 to 28 days) prior to definitive surgery plus three additional doses post-surgery. The second group enrolled sixteen subjects who received four doses of INO-3112 after at least two months following completion of definitive chemoradiation or surgery and adjuvant chemoradiation therapy.