A Multi-Centre, Randomized, Double-Blind, Placebo Controlled Pilot Trial to Assess the Efficacy, Safety, and Tolerability of SPM 927 in Subjects With Postherpetic Neuralgia (PHN).

A Multi-Centre, Randomized, Double-Blind, Placebo Controlled Pilot Trial to Assess the Efficacy, Safety, and Tolerability of SPM 927 in Subjects With Postherpetic Neuralgia (PHN).

The objective of the trial is to investigate the analgesic efficacy of SPM 927 in subjects with moderate to severe neuropathic pain due to Postherpetic Neuralgia (PHN)

Inclusion Criteria:

• Subject has clinically diagnosed painful postherpetic neuralgia present at least six months after healing of a herpes zoster skin rash and has at least one form of allodynia
• Subject must have at least moderate pain (mean pain intensity ≥ 4 out of 10 during the baseline week on Likert scale).

Exclusion Criteria:

• Subject has other conditions that cause pain at least as severe as the postherpetic neuralgia.
• Subject has had any surgical treatment or any neurolytic injections for PHN
• Subject has clinically significant ECG and laboratory abnormalities.
• Subject is receiving treatment with anti-epileptic drugs (AEDs), muscle relaxants, mexiletine, topical analgesics, antidepressants, opioids, non-steroidal anti-inflammatory drugs (NSAIDs), paracetamol, benzodiazepines, and antiviral agents.
• Subject has liver function tests (AST, ALT, alkaline phosphatase, total bilirubin and GGT out of the reference range) > 1,5 x ULN (upper limit of normal) at visit 1
• Subject has serum creatinine ≥ 2 times the upper limit of reference range at Visit 1.