The Study of GW493838, an Adenosine A1 Agonist, in Peripheral Neuropathic Pain

A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel Group Study to Evaluate the Efficacy and Tolerability of a 14 Day Treatment Course of GW493838 50mg Compared to Placebo in Subjects With Peripheral Neuropathic Pain

The purpose of this study was to determine the analgesic effect of GW493838 in patients with post-herpetic neuralgia or peripheral nerve injury caused by trauma or surgery.

Inclusion criteria (subjects must meet all of the following criteria in order to be eligible for this study):

• Females of non-child-bearing potential
• diagnosis of peripheral neuropathic pain as a result of: postherpetic neuralgia (PHN) from shingles for at least 3 months duration OR focal neuropathic pain related to nerve injury caused by trauma or surgery
• defined area of pain

Exclusion criteria

• discontinue agents for the treatment of neuropathic pain
• unable to refrain from alcohol and sedative use during the study
• confounding chronic pain which could not be differentiated from the peripheral neuropathic pain under study
• intractable pain of unknown origin or active infection in the area of nerve injury.
• clinically significant medical history or abnormality found on physical examination, laboratory assessment or ECG at Screening or Baseline
• severe asthma that has required oral corticosteroid use in the last 12 months or the subject had severe asthma that required, at anytime, hospitalization or mechanical ventilation support.
• clinical evidence of major depression (by medical history) except those subjects controlled by SSRIs.
• a known allergy or hypersensitivity to any of the investigational products (including rescue analgesia- acetaminophen), or pharmacological class of the investigational product (i.e. adenosine) and/or investigational product excipients.
• a clinically significant abuse of substances, defined as: Patterns of substance intake consistent with disruption of normal function in society; Past or current impairment of organ function reasonably related to substance intake; Any indication of difficulty in abstaining from substances for the duration of the study.
• had previously participated in a clinical study during the past 30 days in which the subject was exposed to an investigational or non-investigational drug or device
• currently participating in another clinical study in which the subject was exposed to an investigational or non-investigational drug or device
• prior blood reduction (450 mL or more) during the previous 30 days
• at risk of non-compliance
• a woman of childbearing potential or a woman who was lactating.