Efficacy and Safety of TRK-700 in Patient With Post-Herpetic Neuralgia

TRK-700 An Early Phase II Study in Patients With Post-Herpetic Neuralgia -Double Blind Comparison With Placebo-

In Post-Herpetic Neuralgia(PHN) patients:

• To conduct an explorative investigation of the efficacy and safety of repeated oral doses of TRK-700 via a randomized double blind comparative study
• To measure the plasma concentration of TRK-700 and its metabolites

Inclusion Criteria:

• Patients with pain persisting for at least 3 months after the onset of herpes zoster
• Patients whose average pain score on the Numerical Rating Scale (NRS) over the past 24 hours at preliminary enrollment is at least 4

Exclusion Criteria:

• Patients with another skin disease that may affect the evaluation of the pain at the site of PHN
• Patients with pain other than PHN that may affect the evaluation of pain
• Patients with pain that is suspected to be mainly psychogenic
• Patients who have received neurolytic or neurosurgical therapy for PHN