Effects of ICA-105665 Using the Intradermal Capsaicin and Ultraviolet B (UV-B) Models in Healthy Male Subjects

Inclusion Criteria: * Healthy males aged 18 to 55 years (inclusive). * Body mass index (BMI) of 18 to 30 kg/m2. * Non-smokers and smokers of up to 5 cigarettes or equivalent per day. * Must be able to abstain from smoking during residential periods. * Demonstration of positive hyperalgesia as defined by an area of hyperalgesia = 15 cm2 15 minutes after ID administration of 100 µg capsaicin. * Demonstration of negative hyperalgesia as defined by an area of hyperalgesia \< 5 cm2 15 minutes after ID administration of capsaicin vehicle. * Subject with a skin type compatible with the measures, and without significant skin allergies, pigmentary disorders, or any active dermatological conditions that might interfere with the conduct of the study. Exclusion Criteria: * Subject has had a clinically significant illness in the 4 weeks before screening. * Use of prescribed medications and herbal supplements in the 7 days prior to dosing or over the counter preparations, including multivitamins and paracetamol, in the 48 h before dosing. * Subject has a significant history of drug/solvent abuse (within 2 years prior to Day 1), or a positive drugs of abuse test at screening. * Subject with a history of alcohol abuse or currently drinks in excess of 28 units per week (males), or has a positive breath alcohol test at the Screening visit or on Day 1. * Subject has a Heat pain tolerance threshold (HPTT) of = 50°C at screening. * Subjects who do not develop erythema at the highest intensity of UV-B light used to establish Minimum erythema dose (MED). * Known allergy or intolerance to capsaicin or hot peppers. * Subjects who have any skin trauma, scars or other skin disorder or tattoos on their forearms or on the front of their thighs. * Subject with active chronic pain conditions or a history of chronic pain conditions. * Any condition that might interfere with the absorption, distribution, metabolism, and/or excretion of drugs. * Previous ingestion of ICA-105665. * Considering or scheduled to undergo any surgical procedure during the duration of the study. * Prolonged QT/QTc interval (repeatedly = 450 msec). Received any agent known to alter hepatic or renal clearance (e.g., erythromycin, cimetidine, barbiturates, phenothiazines, clarithromycin, troleandomycin, ketoconazole, miconazole, fluconazole, itraconazole, etc.) for a period of 30 days prior to Day 1. * History of risk factors for Torsades de Pointes (family history of long QT syndrome, heart failure, hypokalemia). * Subject is unable to tolerate being blindfolded. * Subject has participated in a clinical study involving capsaicin within 1 year of the Screening visit. * Subject has a history of skin cancer. * Subject has a clinically significant history of anemia.