Agenus completes patient enrolment in HSV-2 therapeutic vaccine study

28th February 2013 (Last Updated February 28th, 2013 18:30)

Biotechnology company Agenus has finished enrolling patients in a double-blind, multicentre, randomised Phase II study of its recombinant therapeutic vaccine for the treatment of genital herpes in herpes simplex virus-2 (HSV-2) positive patients.

Biotechnology company Agenus has finished enrolling patients in a double-blind, multicentre, randomised Phase II study of its recombinant therapeutic vaccine for the treatment of genital herpes in herpes simplex virus-2 (HSV-2) positive patients.

The HerpV vaccine, which is based on the company's HSP platform technology, contains the proprietary QS-21 Stimulon adjuvant, recombinant human heat shock protein-70 complexed with 32 distinct 35-mer synthetic peptides from the HSV-2 proteome.

The study (designated as protocol C-400-02), which has screened 100 HSV-2 positive patients, will test the biological efficacy of HerpV as measured by effect on genital viral shedding after three injections of the therapeutic vaccine.

A booster injection of HerpV will be given at six months after treatment to evaluate the potential durability of treatment effect, according to the company.

"A booster injection of HerpV will be given at six months after treatment to evaluate the potential durability of treatment effect."

During the company's four-arm Phase I study, 35 HSV-2 seropositive patients received three treatments of HerpV (designated in the study as AG-707 plus QS-21), AG-707, QS-21 alone, or placebo at two-week intervals.

The results demonstrated that the vaccine was well-tolerated.

Patients who received HerpV showed a statistically significant CD4+ T cell response (100%; 7/7) to HSV-2 antigens as detected by IFN? Elispot, and the majority of those patients demonstrated a CD8+ T cell response (75%; 6/8).

In addition, Stimulon adjuvant is being used in 17 vaccines, which are currently in clinical development, including four GlaxoSmithKline (GSK) Phase III programmes.

Results from GSK's Phase III trials using MAGE-A3 cancer immunotherapeutic vaccines in lung cancer and melanoma, which incorporate QS-21 Stimulon, are anticipated in 2013.