Sb-705498 Rectal Pain Study

A Double-blind, Randomised, Placebo Controlled, Single Dose, Two-period Crossover Study to Investigate the Therapeutic Potential of the TRPV1 Antagonist SB-705498 in Treatment of Subjects With Rectal Hypersensitivity Including Irritable Bowel Syndrome.

SB-705498 has demonstrated efficacy in several preclinical and human experimental pain models. This study will investigate the efficacy of SB-705498 in patients with rectal pain. This will be a double-blind, placebo-controlled, two-way crossover study. 21 patients with faecal urgency (Group 1), and 21 patients with IBS (Group 2) will complete this study.

Inclusion Criteria:

• Female/male aged 18-65.
• Women of child bearing potential must use an effective method of contraception
• Faecal urgency as defined by Chan
• ECG, which has no abnormalities
• Normal Clinical labs
• Informed consent and understand protocol requirements
• IBS subjects: Has irritable bowel syndrome (IBS) as defined by Rome II criteria
• Rectal hyperalgesia

Exclusion Criteria:

• Any clinical or biological abnormality found at screen (other than those related to the disease under investigation)
• History of alcohol, substance or drug abuse
• Uncontrolled hypertension
• A history or presence of cardiovascular risk factors
• Participation in a trial within 3 months before the start of the study
• History of allergy
• Unable to withdraw from analgesic medications for their rectal hyperalgesia (opioid-dependent patients can be included if they are willing to withdraw from their opiate medication