EMA401 Reduces Pain of Postherpetic Neuralgia in Mid-Stage Trial
AT2 receptor antagonist meets primary endpoint (February 5)
The Lancet has published the results from a phase II trial of EMA401 (Spinifex Pharmaceuticals) in patients with postherpetic neuralgia (PHN). EMA401 is a novel angiotensin II type 2 (AT2) receptor antagonist under development as a potential first-in-class oral treatment for chronic pain without CNS side effects.
PHN is a painful condition that develops in some patients following herpes zoster (shingles). Existing therapy does not relieve the pain in all individuals.
The phase II trial met its primary endpoint by showing that patients randomly assigned to treatment with EMA401 achieved a greater reduction in pain from baseline to the last week of 28 days of treatment compared with patients randomly assigned to receive placebo.
In an analysis of the intent-to-treat population (i.e., all randomized patients), the mean pain-intensity reduction from baseline after 4 weeks of treatment was –2.29 for EMA401 versus –1.60 for placebo (P = 0.007).
In addition, a significantly greater proportion of patients receiving active treatment reported a more than 30% reduction in the mean pain-intensity score compared with baseline (i.e., the responder rate): 57.6% for EMA401 versus 35.2% for placebo (P = 0.0023), meeting a key secondary endpoint.
Source: Spinifex Pharmaceuticals; February 5, 2014.