Agenus Commences Phase 2 Study of HerpV Vaccine for the Treatment of Genital Herpes
Press Release: Agenus Inc. – 7 hours ago
HerpV is the most clinically advanced therapeutic vaccine candidate for the treatment of genital herpes
Contains Agenus' QS-21 Stimulon(R) adjuvant currently being studied in 17 clinical programs
LEXINGTON, Mass., Oct. 23, 2012 (GLOBE NEWSWIRE) -- Agenus Inc. (AGEN), a developer of therapeutic vaccines for cancer and infectious diseases, today announced that it has initiated a Phase 2 randomized, double-blind, multicenter study of HerpV, a recombinant "off-the-shelf" therapeutic vaccine candidate for the treatment of genital herpes in Herpes Simplex Virus 2 (HSV-2) positive subjects. HerpV contains Agenus' QS-21 Stimulon(R)* adjuvant, which is currently being studied in 17 additional clinical programs.
The study designated as protocol C-400-02 will enroll 75 HSV-2 positive subjects who have a history of frequent disease recurrences. The study will test the efficacy of the HerpV vaccine as measured by effect on genital viral shedding. In the study, 65 participants will receive the active treatment, HerpV and QS-21, and a control group of 10 participants will receive placebo. A booster injection will be given at six months after treatment to evaluate the durability of treatment effect.
The HerpV Phase 2 study design has been defined by key opinion leaders in the field. Experts in HSV-2 clinical research believe that a reduction in viral shedding, the driving force behind the spread of genital herpes, is an important surrogate for clinical benefit in potentially reducing recurrent outbreaks.
"Our earlier clinical experience demonstrated an unprecedented immune response with both arms of the immune system (CD8+ and CD4+ T cells) being activated in subjects vaccinated with HerpV and QS-21, but not in subjects receiving placebo," said Garo H. Armen, Ph.D., chairman and CEO of Agenus Inc. "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."
QS-21 is a key component of many vaccines in clinical development. Over the next 15 months additional data from multiple important clinical programs that contain QS-21 are expected to be disclosed. QS-21 is incorporated in several vaccines currently in clinical development, including four GlaxoSmithKline (GSK) Phase 3 programs.
About Heat Shock Protein Platform (HSP) and Recombinant Series HerpV
HerpV is a recombinant therapeutic vaccine for the treatment of genital herpes, which is caused by the herpes simplex virus-2 (HSV-2).
The vaccine is based on Agenus' HSP platform technology, and is administered with Agenus' proprietary adjuvant QS-21 Stimulon(R) adjuvant. HerpV consists of recombinant human heat shock protein-70 complexed with 32 distinct 35-mer synthetic peptides from the HSV-2 proteome. This broad spectrum of herpes antigens is intended to allow for more accurate immune targeting and surveillance, reducing the likelihood of immune escape. Further, the diversity of antigens in HerpV is designed to increase the chance of providing efficacy for a wide segment of the patient population.
In a four-arm, Phase 1 study, 35 HSV-2 seropositive patients received HerpV (designated in the study as AG-707 plus QS-21), AG-707, QS-21 alone, or placebo. Patients received three treatments at two-week intervals. The vaccine was generally well tolerated, with injection site pain as the most common reported adverse event. All patients who received HerpV and were evaluable for immune response showed a statistically significant CD4+ T cell response (100%; 7/7) to HSV-2 antigens as detected by IFNγ Elispot, and the majority of those patients demonstrated a CD8+ T cell response (75%; 6/8). This study was published in the scientific journal Vaccine.
For more details about the HerpV C-400-02 study, please visit www.clinicaltrials.gov using the identifier NCT01687595. The HerpV C-400-02 study participating centers include the following:
University of Washington Virology Research Clinic
Seattle, WA 98104