Inovio's SynCon vaccine for HPV types 6 and 11 induces CD8+ T cells in mice

Inovio Pharmaceuticals, Inc. (NYSE AMEX: INO) announced today that its SynCon® therapeutic vaccine for human papillomavirus (HPV) types 6 and 11, which are associated with head & neck cancers and genital warts, among other conditions, induced strong antigen-specific CD8+ T cells in mice. This vaccine is complementary to Inovio's VGX-3100, a therapeutic vaccine targeting cervical dysplasias and cancers caused by HPV types 16 and 18, which is in a phase II clinical study for CIN 2/3. This positive animal data mirrors the similarly robust T-cell responses induced by VGX-3100 in earlier mice studies. These results were reported in a peer-reviewed paper titled, "Induction of robust cellular immunity against HPV6 and HPV11 in mice by DNA vaccine encoding for E6/E7 antigen," which has been published in Human Vaccines & Immunotherapeutics.

Dr. J. Joseph Kim, President and CEO, said, "Over a dozen HPV types are recognized as causing cancers and other diseases, with a significant health need and business opportunity for therapeutic vaccines to address these conditions. With the best-in-class T-cell responses generated by VGX-3100 in early human studies, our goal is to create a family of therapeutic vaccines targeting most significant diseases caused by HPV infection, including cervical cancer and dysplasia, vulvar dysplasia, head and neck cancer, and other cancers. This study demonstrates our ability to readily extend our therapeutic solutions to diseases caused by different HPV types. Importantly, our clinical experience with VGX-3100 may also help streamline the regulatory path for these related vaccines."

HPV types 6 and 11 are the major cause of recurrent respiratory papillomatosis and genital warts. They are also associated with otolaryngologic (ear, nose, and throat) malignancies, carcinoma of the lung, tonsil, larynx, and low-grade cervical lesions.

Similar to Inovio's VGX-3100, two novel engineered DNA vaccines were developed to target the antigens E6 and E7 of HPV 6 and HPV 11. After designing consensus sequences of these antigens with the purpose of providing broader cross-strain therapeutic effects, the vaccines were also modified to increase gene expression and production of the antigenic protein. These vaccines were delivered using Inovio's proprietary electroporation delivery system. Together such highly optimized SynCon® vaccines delivered using electroporation have achieved best-in-class immune responses targeting cervical dysplasia and HIV. This study revealed that robust T cell immune responses (especially the important CD8+ T cells) were generated by the HPV 6 and 11 vaccine, as measured by the standard ELISpot assay.