Genocea announces new data that supports novel approach for development of HSV-2 vaccine

Genocea Biosciences announced today the presentation of new data supporting its novel approach to developing a first-in-class, protein subunit therapeutic vaccine for Herpes Simplex Virus type 2 (HSV-2). The data, to be presented this week at the 37th annual International Herpesvirus Workshop (IHW) in Calgary, Alberta, highlight antigens identified through Genocea's unique technology platform that stimulate T cell immune responses to HSV-2. A candidate vaccine consisting of these antigens reduced viral shedding and clinical disease when tested in a preclinical model of HSV-2 infection.

"We are highly encouraged by these data, which mark the first time a protein subunit therapeutic vaccine has been shown to affect disease and viral shedding significantly in this model," said Jessica Flechtner, Ph.D., Vice President, Research, Genocea Biosciences. "As we advance toward the clinic, these data give us great confidence in our lead vaccine candidate, and suggest that we have identified full protein antigens that stimulate a balanced and effective B and T cell immune response."

In one of two studies presented, Genocea researchers studied the T cell immune responses to each HSV-2 protein among patients with HSV-2 infection or exposure. Using ATLAS™, Genocea's proprietary high-throughput screening platform, they identified HSV-2 proteins (or antigens) associated with protective immune responses in volunteers who had no evidence of infection but had been exposed to HSV-2, or who had relatively mild HSV-2 infections. Patients with severe disease, as indicated by multiple outbreaks of genital herpes, had weaker or no responses to these same proteins.

Genocea advanced one antigen, ICP4, and evaluated its therapeutic effectiveness when formulated as a vaccine with glycoprotein D in subsequent studies. In a therapeutic efficacy model, vaccinated guinea pigs showed a 45 percent reduction in duration, and a 55 percent reduction in severity, of clinical symptoms. Furthermore, no measurable virus was found in the reproductive tract of the vaccinated animals after completion of the immunization course.