Radiprodil, formerly known as RGH-896, is an orally bioavailable and selective NMDA receptors antagonist which was evaluated as potential treatmen of neuropathic pain associated with diabetic peripheral neuropathy (DPNP). Treatment with radiprodil did not show statistically significant or clinically meaningful reductions in mean daily pain scores, the primary endpoint, compared to placebo for any of the dosages studied. Based on preclinical pharmacology Radiprodil was a potential therapeutic agent in treatment of neuropathic pain and possibly other chronic pain conditions.