An immunomodulating dipeptide, SCV-07, is a potential therapeutic for recurrent genital herpes simplex virus type 2 (HSV-2)

Herpes simplex virus type 2 (HSV-2) infections produce a recurrent disease state associated with susceptibility to other pathogens, including human immunodeficiency virus (HIV), and cannot be cured by current therapeutic treatments. The HSV-2 epidemic must therefore be addressed by therapeutic strategies that reduce recurrent lesions and ideally lack the possibility for development of drug resistance. To this end, the therapeutic potential of SCV-07 (gamma-d-glutamyl-l-tryptophan), a synthetic dipeptide with potent immunomodulatory and antimicrobial activity, was studied in the guinea pig model of recurrent genital HSV-2. Initial evaluations showed that when delivered orally, but not subcutaneously, SCV-07 significantly reduced recurrent lesions. Oral dose ranging studies indicated that, of the tested amounts, 5 μg/kg was optimal when delivered after an overnight fast. Interestingly, fasting induced a significant increase in recurrent lesions in vehicle-treated guinea pigs relative to non-fasted animals. Despite this increase, SCV-07 significantly reduced lesion formation in treated animals but showed no durability following cessation of treatment. In fact, this regimen of SCV-07 treatment produced statistically indistinguishable outcomes compared with those provided by topical aciclovir. These data illustrate that SCV-07 may provide an easily administered alternative or supplemental treatment option for genital HSV-2 recurrent disease.