Simplirix (GSK)

Simplirix (gD-AS04) is a recombinant subunit vaccine developed by GSK for the prevention of genital herpes. It contains a truncated version of the herpes simplex virus type 2 (HSV-2) glycoprotein D (gD), which is a key protein involved in viral entry into host cells. The antigen is formulated with GSK's proprietary AS04 adjuvant system, a combination of aluminum hydroxide (Alum) and the Toll-like receptor 4 (TLR4) agonist 3-O-desacyl-4'-monophosphoryl lipid A (MPL). The vaccine was evaluated in a large-scale Phase 3 trial (the Herpevac trial) involving over 8,000 HSV-1 and HSV-2 seronegative women. While the vaccine showed approximately 58% efficacy against genital herpes disease caused by HSV-1, it failed to provide significant protection against HSV-2 disease or infection, the primary goal of the development program. Consequently, development was discontinued.

Brand names

Simplirix

Other names

gD-Alum/MPL vaccineHerpevac vaccineHSV-2 gD vaccineHSV2 gD vaccineHSV 2 gD vaccinegD-AS04 vaccinegD-AS-04 vaccinegD-AS 04 vaccine