Genital Herpes and Herpes Simplex Virus Type-2 (HSV-2)

• HSV-2 is a sexually-transmitted virus that is the leading cause of recurrent genital herpes worldwide.
• Approximately 16% of the U.S. population and 11% of the worldwide population aged 15 to 49 are infected with HSV-2.
• Nearly 20 million new HSV-2 infections occurred worldwide in 2012, with the highest rates among younger age groups.
• Most people infected with HSV-2 experience recurrent episodes of painful genital lesions. An infected person may shed virus even when they do not have lesions, which can increase the risk of transmission to an uninfected partner.
• There is currently no cure for HSV-2 infection; antiviral drugs can decrease genital lesions, viral shedding and transmission. Despite the availability of antivirals for the past 30 years, HSV-2 prevalence rates remain largely unchanged.
• The continuing physical and psychological toll of recurrent genital herpes highlights the need for novel treatment modalities such as therapeutic vaccines.

VCL-HB01: Vical’s Therapeutic HSV-2 Vaccine

• Vical’s bivalent DNA vaccine candidate, VCL-HB01, encoding full-length HSV-2 UL-46 and gD antigens, was developed in collaboration with leading HSV-2 experts at the University of Washington.
• In a Phase 1/2 randomized, double-blind, placebo-controlled trial of 165 HSV-2 infected adults, VCL-HB01 demonstrated a statistically significant reduction in genital lesion rate compared to baseline.
• A Phase 2 randomized, double-blind, placebo-controlled trial in approximately 225 HSV-2 infected adults has been underway since September 2016 to evaluate the primary efficacy endpoint of reduction in annualized recurrence rates over a 12-month follow-up period. Recurrence rate is one of the most clinically meaningful endpoints for patients and treating physicians as it provides information on both the number and spacing of recurrences over time in this chronic disease setting. For more information, please go to the NCT02837575 trial listing at ClinicalTrials.gov.

References

• Corey et al., NEJM 2004
• Looker et al., PLOS One, 2015
• Mammen et al., ASM Microbe 2016
• Muller et al., JGV 2009
• WHO Guidelines for the Treatment of Genital Herpes Simplex Virus 2016
• Xu et al., MMWR 2010