Immunogenicity Data from Phase 1/2a Trial Highlighted at 39th Annual International Herpesvirus Workshop

CAMBRIDGE, MA, USA I July 22, 2014 I Genocea Biosciences, Inc. (GNCA), a clinical-stage biopharmaceutical company developing T cell-enabled vaccines and immunotherapies, today presented data from a Phase 1/2a study of GEN-003, the Company’s investigational immunotherapy against HSV-2, demonstrating that the immunotherapy elicited T cell, IgG and neutralizing antibody responses that remained significantly above baseline for 12 months after treatment. The data were presented at the 39th Annual International Herpesvirus Workshop, being held July 19-23, 2014 in Kobe, Japan.

“Prior HSV-2 immunotherapy candidates investigated by others have failed to meet their clinical endpoints because in each case, these immunotherapies elicited serum neutralizing antibodies against the virus but failed to trigger effective CD4+ and CD8+ T cell responses against HSV-2 infected cells. As a result, experts have called for next-generation immunotherapies capable of dispatching T cells to combat HSV-2 infected cells, to limit both viral shedding and symptom recurrences,” said Jessica Baker Flechtner, Ph.D., Genocea senior vice president of research. “In this trial, at a dose that reduced viral shedding by up to 52 percent, more than 90 percent of subjects demonstrated vaccine-induced T cell responses, defined as greater than 3.5 fold increases from baseline, which remain significantly elevated even 12 months after treatment.”

The data were part of an oral presentation by Dr. Flechtner entitled “T cell and Antibody Responses of Subjects Participating in GEN-003-001, a Phase 1/2a Clinical Trial to Evaluate the Safety and Immunogenicity of a Novel Therapeutic Vaccine Against HSV-2.”

About GEN-003

GEN-003 is Genocea’s lead product candidate and is a T cell-enabled immunotherapy intended to reduce the transmission risk and clinical symptoms of HSV-2. In a Phase 1/2a study, patients showed statistically significant reductions in viral shedding and genital lesion rates of up to 52 percent and 65 percent respectively, with a durability of effect to six months after dosing in the 30µg dose group. A Phase 2 dose optimization study is currently ongoing. GEN-003 was designed with insights from Genocea’s ATLAS™ platform. ATLAS™ profiles the comprehensive spectrum of actual T cell responses mounted by humans in response to disease, enabling the identification of antigen targets which drive protective T cell responses with which to design potential new vaccines and immunotherapies.

For more information about GEN-003, please visit http://www.genocea.com/platform-pipeline/pipeline/gen003-for-hsv-2/.

About HSV-2

Herpes simplex virus type 2 (HSV-2), the most common cause of genital herpes, is a sexually transmitted disease that is estimated to infect more than 500 million people worldwide. In the United States roughly 15 percent of the adult population, or 40 million people, are infected. HSV-2 infection can cause recurring, painful genital sores, and can be stigmatizing and produce considerable psychological distress in patients. The disease is particularly severe in immunosuppressed patients and poses significant risk to newborns if it is transmitted from mothers during birth. While antiviral drugs are used widely to treat HSV-2, there is neither a cure nor a vaccine for this disease.

About Genocea

Genocea is harnessing the power of T cell immunity to develop life-changing vaccines and immunotherapies. T cells are increasingly recognized as a critical element of protective immune responses to a wide range of diseases, but traditional discovery methods have proven unable to identify the targets of such protective immune response. Using ATLAS™, its proprietary technology platform, Genocea identifies these targets to potentially enable the rapid development of medicines to address critical patient needs. Genocea’s pipeline of novel clinical stage T cell-enabled product candidates includes GEN-003, in development for HSV-2 therapy; GEN-004, in development to prevent infections caused by pneumococcus; and earlier-stage programs in chlamydia, HSV-2 prophylaxis, malaria and cancer immunotherapy. For more information, please visit the company’s website at www.genocea.com.

SOURCE: Genocea Biosciences