The study termed as protocol C-400-02 will enroll 75 HSV-2 positive patients to test the efficacy of the HerpV vaccine as measured by effect on genital viral shedding.
Of 75 participants, 65 will receive HerpV and QS-21 while the rest will receive placebo along with a booster injection at six months after treatment to evaluate the durability of treatment effect.
Agenus chairman and CEO Garo Armen said earlier clinical experience demonstrated an immune response with CD8+ and CD4+ T cells being activated in subjects vaccinated with HerpV and QS-21, but not in subjects receiving placebo.
"Incorporating a broad spectrum of herpes antigens along with QS-21 has the potential enable the immune system’s ability to recognize and destroy HSV-2 infected cells," Armen added.
QS-21 is a key component of many vaccines in clinical development, which also includes four GlaxoSmithKline phase 3 programs.