Study of Itch Control by VLY-686 in Healthy Volunteers After Intradermal Injections of Substance P

Inclusion Criteria: * Males 18 - 45 years of age, inclusive; * Non-smokers, per medical history, or ex-smokers for a period of ≥1 year; * Subjects with Body Mass Index (BMI) of ≥18.5 and ≤30 kg/m2 (BMI = weight (kg)/ \[height (m)\]2); * Vital signs (in sitting position after 3 minutes of rest) which are within the ranges shown below (inclusive): * Body temperature between 35.4-37.8 °C; * Systolic blood pressure between 91-130 mmHg; * Diastolic blood pressure between 51-90 mmHg; * Pulse rate between 50-100 bpm; * Respiratory rate between 10-20 breaths per minute; * Ability and acceptance to provide written informed consent; * Willing and able to comply with study requirements and restrictions; * Subjects must be in good health as determined by past medical history, physical examination, electrocardiogram, clinical laboratory tests and urinalysis. Exclusion Criteria: * Past or present history of atopy (atopic dermatitis problems, urticaria, asthma or allergic rhinitis) with no ascertained intolerance to histamine; * Past or present skin disease; * Lesions or any skin changes in the forearms in the month prior to the Screening Visit; * History of neurological diseases; * Past or present pain-related diseases such as cluster headaches, migraine, or back pain; * Treatment with all topical cream and ointments including cosmetics applied on the forearm in the 10 days prior to the screening visit; * Participation in the evaluation of any investigational product for 3 months before this study, calculated from the first day of the month following the last visit of the previous study; * Exposure (within 2 weeks of the Baseline Visit) to any prescription medication or over-the-counter medication including dietary supplements and/or herbal remedies, except those listed on Section 8.2; * Exposure (within 4 weeks of the Screening Visit) to any antihistamines, anxiolytics, antidepressants, pain killers including triptanes, neuroleptics, or sleep medications; * Treatment with any medication known to cause major organ system toxicity (e.g., chloramphenicol or tamoxifen) during the 60 days preceding the Screening Visit; * Administration of medications containing corticosteroids or adrenocorticotropic hormone in the three months prior to the Screening Visit; * Electrocardiogram reading considered outside the normal limits by the investigator (e.g. abnormally prolonged QTc corrected by Fridericia's method \> 450 msec in males, on ECG tracing). The following conduction abnormalities may confound QTc analysis and should be avoided if possible: PR \> 220 msec, 2nd or 3rd degree AV block, intraventricular conduction delay with QRS \> 120 msec, left branch bundle block, right branch bundle block or Wolff-Parkinson-White syndrome; * Blood donation in the last 3 months or donation of at least 1500 mL blood (including this study) within the last year; * History of liver disease and/or positive for one or more of the following serological results: * A positive hepatitis C antibody test (anti-HCV); * A positive hepatitis B surface antigen (HBsAg); * A positive HIV test result ; * Not willing to sign the informed consent or not able to understand completely the study objectives or risks; * Clinically relevant abnormalities in clinical lab or physical assessments performed at the screening visit; * Lack of sensitivity to Substance P and histamine or sensitivity to saline at the Screening Visit; * Any other sound medical reason as determined by the clinical Investigator. * Drug, alcohol, caffeine, tobacco: history of drug, alcohol (\>2 drinks/day for males, defined according to USDA Dietary Guidelines 2010), caffeine (\>5 cups coffee/tea/day), smokers; * Diet: abnormal diets (\<1600 or \>3500 calories/day) or substantial changes in eating habits in the 4 weeks before this study; vegetarians.