Herpes Simplex Vaccine Reduces Symptoms at 6 Months
Early-stage trial achieves reductions in both clinical lesion days and rate of viral shedding
GEN-003 (Genocea Biosciences), a vaccine candidate under development for the treatment of herpes simplex virus type 2 (HSV-2) infection, has provided significant reductions in both the number of clinical lesion days and the rate of viral shedding at 6 months after the final vaccine dose in an early-stage (phase I/IIa) trial.
The new findings were reported at the World Vaccine Congress, being held March 24–26 in Washington, D.C.
The ongoing phase I/IIa double-blind, placebo-controlled study showed that patients receiving GEN-003 (30 mcg) experienced a 72% reduction in lesion days 6 months after initiation of the study compared with baseline levels (P < 0.001). The new results expand on positive initial data reported in September 2013, which showed that patients treated with GEN-003 experienced a 50% reduction in mean viral shedding from baseline (P < 0.001) immediately after three doses. This improvement was maintained at 6 months (P < 0.001).
GEN-003 is a first-in-class T-cell vaccine candidate designed to reduce the transmission risk and clinical symptoms of HSV-2 by inducing a balanced B-cell (antibody) and T-cell immune response, which is believed to be critical to achieving long-term control of HSV-2. GEN-003 includes fragments of ICP4 and gD2 antigens, as well as the proprietary adjuvant Matrix-M, licensed from Novavax, Inc. The adjuvant is a novel saponin-derived product that has demonstrated a B- and T-cell immunostimulatory profile in previous clinical studies.
The new study involves 143 volunteers with a history of moderate-to-severe recurrent HSV-2 infection at clinics in the U.S. The subjects were enrolled into one of three dose cohorts (10, 30, or 100 mcg of each protein) and were randomly assigned within cohorts to receive either GEN-003, vaccine antigens without adjuvant, or placebo. The subjects received three injections of the assigned treatment into an arm muscle at 21-day intervals and are being followed for 1 year after the third injection.
Source: Genocea Biosciences; March 24, 2014.