 A number of selective Nav1.7 (and/or Nav1.8) blockers are in clinical development, including funapide (TV-45070, XEN402), PF-05089771, DSP-2230, NKTR-171, GDC-0276, and RG7893 (GDC-0287).Ralfinamide (formerly NW-1029, FCE-26742A, PNU-0154339E) is a multimodal, non-selective Nav channel blocker which is under development for the treatment of pain.Surprisingly, many potent Nav1.7 blockers have been found to be clinically effective but only relatively weak analgesics.