Raptor Pharmaceutical Corp. ("Raptor" or the "Company") (Nasdaq: RPTP) today announced the presentation of clinical trial data on NGX426, the Company's orally administered, non-opioid, AMPA/kainate receptor antagonist, at the 12th International Conference on the Mechanisms and Treatment of Neuropathic Pain, held on November 20-21 in San Francisco. The results of the study led by Mark Wallace, M.D., Professor of Clinical Anesthesiology at the Center for Pain Medicine of the University of California at San Diego, suggested that NGX426 could be effective in a variety of neuropathic pain states, which are caused by damage to or dysfunction of the peripheral or central nervous system rather than stimulation of pain receptors.
The objective of the single center, double-blind, randomized study conducted by Dr. Wallace was to demonstrate that the orally administered prodrug NGX426, maintains the analgesic effect previously shown for the active moiety, tezampanel. Using a cross-over design, a total of 18 study subjects received single doses of 90 mg of NGX426, 150 mg of NGX426 or placebo in each of three treatment periods. Pain was induced by injecting 250 ug (microgram) of capsaicin under the skin of the forearm at 30 minutes and 120 minutes after dosing.
The 150 mg dose showed statistically significant reductions in spontaneous pain versus placebo after the 30 minute and 120 minute capsaicin injection time points. At the 150 mg dose, reductions in elicited pain were also statistically significant versus placebo. The 90 mg dose of NGX426 showed statistical significance versus placebo after the 30 minute time point on reduction of spontaneous pain, hyperalgesia (increased sensitivity to pain) and allodynia (pain due to a stimulus which does not normally provoke pain). After the 120 minute time point, the 90 mg dose was statistically significant for hyperalgesia and allodynia. NGX426 was well tolerated, all subjects completed the three treatment periods, and the most common adverse events attributed to NGX426 were mild somnolence and dizziness.