A Phase 2b Trial of EPB-348 for the Treatment of Herpes Zoster


The purpose of this study is to determine the pharmacokinetics and dosage of EPB-348 that best balances safety and efficacy among adult immunocompetent patients with an acute episode of herpes zoster.

Full Title of Study: “A Randomized, Double-blind, Active-controlled, Multi-center, Parallel-group Dose-ranging Study Assessing the Safety and Efficacy of EPB-348 Versus Valacyclovir Among Immunocompetent Patients With an Acute Episode of Herpes Zoster”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
  • Study Primary Completion Date: June 2009

Detailed Description

In cells infected with varicella-zoster virus, there is evidence to suggest that EPB-348 could offer clinically important advantages in the treatment of acute herpes zoster over currently available therapies due to rapid absorption and conversion to the active moiety as well as a longer intra-cellular half-life in infected cells. Clinically, these characteristics could translate into once-daily dosing versus thrice-daily dosing as seen with current therapy, leading to a higher rate of compliance and quality-of-life, especially among elderly patients. The objective of EPB348-0201 is to determine the pharmacokinetics and dosage of EPB-348 that best balances safety and efficacy among adult immunocompetent patients with an acute episode of herpes zoster. This multi-center study will randomly assign patients to either EPB-348 1000 mg once daily or EPB-348 2000 mg once daily or valacyclovir 1000 mg three times daily.


  • Drug: EPB-348
    • Treated over seven days
  • Drug: Valacyclovir
    • Treated over seven days

Arms, Groups and Cohorts

  • Experimental: EPB-348 1000 mg
    • EPB-348 1000 mg dosed once daily for seven days
  • Experimental: EPB-348 2000 mg
    • EPB-348 2000 mg dosed once daily for seven days
  • Experimental: EPB-348 3000 mg
    • EPB-348 3000 mg dosed once daily for seven days
  • Active Comparator: Valacyclovir
    • Valacyclovir 1000 mg dosed three times daily for seven days

Clinical Trial Outcome Measures

Primary Measures

  • To compare the time-to-crusting of vesicles on patients in each of the EPB-348 dosing arms versus the valacyclovir dosing arm.
    • Time Frame: Daily assessment during the seven days of treament then weekly until Day 28

Participating in This Clinical Trial

Inclusion Criteria

  • Male and female adults at least 18 years of age
  • Patients with signs and symptoms consistent with acute herpes zoster disease, namely, a dermatomal vesicular rash which may be preceded by pain and parasthesias in the days before vesicular eruption
  • Herpes Zoster associated rash present for ≤ 72 hours
  • Patients who are deemed to be immunocompetent based on history and physical exam

Exclusion Criteria

  • Females who are pregnant or nursing
  • History or clinical manifestations of significant metabolic, hematological, pulmonary, ischemic, or unstable heart disease, gastrointestinal, neurological, psychiatric, renal, urological, endocrine, opthalmologic, or immune mediated disease including HIV or HBsAg positivity
  • Chronic genital herpes
  • Patients who received cytotoxic or immunosuppressive drug therapy within 3 months prior to study participation
  • Previous vaccinations against Herpes Zoster
  • Patients with > 50% of vesicles crusted at screen
  • Patients who received topical or systemic antiviral medications or immunomodulatory agents for herpes zoster viral infections or capsaicin within 4 weeks of study participation
  • Patients with a history of congenital, acquired, or corticosteroid induced immunodeficiency, including malignancy, significantly impaired renal function (creatinine clearance < 50 cc/min), and impaired hepatic function (ALT or AST levels > 3 times the upper limit of normal)
  • QTc > 500msec
  • Patients with a history of intolerance or hypersensitivity to acyclovir, penciclovir, valacyclovir, or famciclovir
  • Patients with gastrointestinal dysfunction that might interfere with drug absorption
  • Patients, considered by the investigator, for any reason, to be an unsuitable candidate for receiving the study drug

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Epiphany Biosciences
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Stephen K Tyring, MD, Principal Investigator, University of Texas Health Science Center, Houston, Texas

Citations Reporting on Results

Tyring SK, Plunkett S, Scribner AR, Broker RE, Herrod JN, Handke LT, Wise JM, Martin PA; Valomaciclovir Zoster Study Group. Valomaciclovir versus valacyclovir for the treatment of acute herpes zoster in immunocompetent adults: a randomized, double-blind, active-controlled trial. J Med Virol. 2012 Aug;84(8):1224-32. doi: 10.1002/jmv.23329.

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