Date: 2014-06-26
Type of information: Results
phase: 2
Announcement: results
Company: Agenus (USA)
Product: HerpV
Action
mechanism: HerpV is a recombinant therapeutic vaccine for genital herpes caused by the herpes simplex virus-2 (HSV-2). The vaccine is based on Agenus\' HSP platform technology, and contains Agenus’ proprietary QS-21 Stimulon, a plant-derived adjuvant that boosts specific immune responses. HerpV consists of recombinant human heat shock protein-70 complexed with 32 distinct 35-mer synthetic peptides from the HSV-2 proteome.
Disease: genital herpes
Therapeutic area: Infectious diseases
Country:
Trial
details: A total of 80 subjects with a history of 1-9 herpes recurrences within the prior 12 months were randomized into the trial and 70 subjects received the active treatment, HerpV and QS-21 Stimulon, and 10 subjects received placebo. Three injections of HerpV at a dose of 240 µg (includes12 µg of a mix of 32 different HSV-2 antigenic peptides) or placebo were given at two week intervals. HSV-2 activity in the genito-urinary tract was monitored by PCR for HSV-2 DNA in genital swabs for 45 days before and after the initial course of three vaccinations.
Latest
news: * On June 26, 2014, Agenus, an immuno-oncology company developing a portfolio of checkpoint modulators (CPMs), heat shock protein peptide-based vaccines, and adjuvants, announced Phase 2 results for HerpV, a synthetic vaccine candidate for the treatment of patients with genital Herpes Simplex Virus-2 (HSV-2). In a randomized, Phase 2, double-blind, multi-center study, the majority of patients showed an immune response to the HSV antigens after a series of vaccinations and a booster dose at six months. More than half of those vaccinated developed a robust anti-HSV cytotoxic T-cell immune response, and in those patients there was a statistically significant 75% reduction in viral load (P<0.001; CI: 46.2 – 88.6%). This level of reduction in viral load has the potential to result in reduced incidence and severity of herpetic outbreaks and a reduction in viral transmission. After the booster shot, HerpV demonstrated a durable reduction in viral shedding approximating 14% (RR=0.86 and CIs: 0.58-1.26) and remains consistent with the reduction in viral shedding observed during the initial treatment period. The protocol defined secondary analyses were viral load and viral shedding after the booster shot, the primary endpoint of the study was reported in November 2013. In this study, the booster shot was given six months after the first vaccination. Patients continue to be followed for safety and long-term immune response. HerpV reported adverse events have mostly been in line with expectations for a therapeutic vaccine and with effects commonly associated with QS-21 Stimulon®adjuvant. These adverse events are short-lived and include flu-like symptoms and injection-site reactions.Agenus is now looking forward to advancing discussions with potential partners to take this program into the next phase of clinical research. The primary analysis, which looked at viral shedding after the initial three HerpV vaccinations, demonstrated that subjects who received HerpV had a statistically significant reduction in viral shedding (P=0.015; RR=0.85). These results suggest a 15% reduction in viral shedding after the initial treatment period before the administration of the booster injection. The results also demonstrate a reduction in viral load of 34% (P=0.08). Placebo patients showed no reduction compared to baseline in either parameter. Notably, patients were not on any anti-viral treatments during their swabbing period.
