The Efficacy of MK-8291 in Participants With Post-herpetic Neuralgia (PHN) With Allodynia (MK-8291-012)
Condition: Postherpetic Neuralgia
MeSH terms: Neuralgia; Neuralgia, Postherpetic; Hyperalgesia
Intervention: MK-8291; Placebo
Intervention description: MK-8291 oral tablets; Placebo oral tablets
Phase: Phase 1
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Enrollment: 35.0
Sex: All
Minimum age: 18 Years
Healthy volunteers: No

Summary:

      This study aims to determine whether MK-8291 is effective in reducing pain in participants
      with post-herpetic neuralgia (PHN) with allodynia.

      The primary hypothesis is that when compared to placebo, treatment with MK-8291 reduces the
      change from Baseline in participant-reported pain intensity by 1 on an 11-point numeric
      rating scale.
    

Eligibility criteria:

        Inclusion Criteria:

          -  non-pregnant female (and/or partner) agrees to use two acceptable methods of birth
             control throughout the trial until 2 weeks after the last dose of treatment

          -  female is postmenopausal or surgically sterile

          -  has a clinical diagnosis of PHN with allodynia for at least 3 months duration after
             healing of rash

          -  has a body mass index (BMI) =< 35 kg/m^2, inclusive

          -  is in good health, with exception of PHN

          -  is on a stable dose for at least 30 days prior to screening if taking any of the
             following: opioids, non-opioids, paracetomol, non-steroidal anti-inflammatory drugs
             (NSAIDs), aspirin, antidepressants

          -  is a nonsmoker or has not used nicotine or nicotine containing products for at least
             prior 3 months

        Exclusion Criteria:

          -  has a non-PHN chronic pain state

          -  has a history of clinically significant and inadequately treated endocrine,
             gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal,
             respiratory, genitourinary, or major neurological (including stroke and chronic
             seizures) abnormalities or diseases

          -  has a history of malignant cancer

          -  has a history or presence of esophagitis

          -  has a history of significant multiple and/or severe allergies (e.g. food, drug,
             latex), or has had an anaphylactic reaction or significant intolerability to
             prescription or non-prescription drugs or food

          -  is positive for hepatitis B surface antigen, hepatitis C antibodies, or human
             immunodeficiency virus (HIV)

          -  had major surgery, donated or lost approximately 500 mL of blood within 4 weeks prior
             to screening

          -  has participated in another investigational trial within 4 weeks prior to screening

          -  has a history of risk factors for Torsades de Pointes, has hypokalemia or
             hypomagnesemia

          -  has a history or presence of clinically significant cardiac arrhythmia, taking
             substances with the target of reducing heart rate and or exercising endurance sports

          -  has had an injection of local anesthetics or steroids in the region affected by PHN,
             within 35 days prior to randomization

          -  anticipates using prescription and non-prescription drugs or herbal remedies during
             trial

          -  consumes excessive amounts of alcoholic or caffeinated beverages

          -  uses cannabis, any illicit drugs, or has a history of drug (including alcohol) abuse
             within 12 months of screening visit