BLUE BELL, Pa., Oct. 10, 2012 /PRNewswire/ -- Inovio Pharmaceuticals, Inc. (NYSE MKT: INO) announced today clinical results indicating that its VGX-3100 therapeutic synthetic vaccine is capable of not only driving robust immune responses to antigens from high risk types of human papillomavirus (HPV) infection but that these immune responses displayed a powerful killing effect on cells changed by HPV into precancerous dysplasias. This desirable effect may ultimately contribute to the regression or elimination of cervical dysplasia and cervical cancer. Inovio is currently assessing the ability of its DNA-based VGX-3100 to treat cervical dysplasias caused by HPV infection in a global phase II trial.
Results from this phase I trial appeared today in the peer-reviewed journal, Science-Translational Medicine, in an article entitled, "Immunotherapy against HPV 16/18 generates potent Th1 and cytotoxic cellular immune responses."
The paper reports that 100% of patients (18 of 18) enrolled in the phase I dose-escalating trial showed antigen-specific antibody responses to Inovio's vaccine, while 78% showed T-cell responses in the validated ELISpot assay. Further tests of T-cell immunity measured the ability of CD8+ T-cells from vaccinated patients to kill cells displaying HPV antigens on their surface: 91% of patients who developed T-cell responses showed the presence of CD8+ T-cells capable of this type of killing activity (so-called "killer T-cells"), which is believed to be critical for the treatment of cervical dysplasia and ultimately cancer caused by HPV.
Dr. J. Joseph Kim, Inovio's President and CEO, said, "Today's milestone is convincing evidence that a DNA-based immune therapy can generate potent and durable T-cell responses in people. Our ongoing phase II efficacy trial is designed to show that the immune responses seen in this study, in particular the generation of killer T-cell responses, may reverse cervical disease caused by chronic HPV infection.""The type of T-cell killing activity seen in this new data provides a growing foundation for efficacy trials focused on the treatment of HPV-associated cancers including cervical, head and neck, and anogenital cancers," Dr. Kim added.