The purpose of this study is to investigate the effect of JNJ-39758979 compared to placebo on histamine induced itch in healthy male volunteers.

The goal of this study is to evaluate the effect and safety of a single oral dose of JNJ-39758979 on histamine-induced itch and hive in 24 healthy male volunteers. This is a three-treatment, double-blind (neither the volunteer nor the study physician will know the identity of the treatment), cross-over (each volunteer receives all three treatments) study. The study is also randomized, meaning that the order in which treatments are given is determined randomly (by chance, like flipping a coin). The total participation time is approximately 8 to 9 weeks, which includes a screening visit, three treatment periods, two wash-out periods (breaks), and a follow-up visit after the third treatment period. All three treatment periods require a 2-day stay in the clinic. Volunteers will have a histamine test at the screening visit and three times during each treatment period (total of 10 tests). The histamine test consists of an injection of a small amount of histamine solution into the upper layer of the skin, which may cause itchiness, a flare response (redness on the skin) and wheal response (elevated bump in the skin) lasting for 30 to 60 minutes. Volunteers will be blindfolded during the procedure and asked to rate the severity of the itch. The areas of the wheal and flare will be measured by a laser scanner, which will not cause harm to the volunteer. During the treatment periods, volunteers will receive the histamine test on the day before study drug and/or placebo is given and at 2 and 6 hours after study drug and/or placebo is given. During the study, safety evaluations, which will include ECGs (a cardiac function test) and vital signs, will be performed, and side effects will be monitored. Blood and urine samples will be collected at the screening visit, during the first day of each treatment period in the clinic and at the follow-up visit for evaluation. Volunteers will receive single doses of 600mg JNJ-39758979, placebo, and 10mg cetirizine in random order over three treatment periods. The first two treatment periods will be followed by an approximately 14 day wash-out period.

Inclusion Criteria:

• Non-smoker or ex-smoker for at least 3 months
• Should generally be in good health
• Must have negative urine alcohol and drug tests
• Must consent to utilize a medically acceptable method of contraception throughout the study and for three months after the last dose of study drug and not donate sperm during the study and for 3 months after receiving the last dose of study drug

Exclusion Criteria:

• Positive for hepatitis B, hepatitis C, or HIV
• History of drug or alcohol abuse within the past two years
• Known allergies, hypersensitivity, or intolerance to cetirizine (Zyrtec)
• Any confirmed significant reactions against any drug
• Active skin diseases
• History of atopic disease or evidence of allergen sensitization by skin prick testing to common aeroallergens
• Use of antihistamines or antidepressants with antihistamine properties within the last 7 days, prescription medication within the last 14 days or Monoamine oxidase inhibitors (MAOIs) within the last 21 days
• Have received an investigational drug or device within the past 3 months