Sodium channel inhibitor helped with postoperative pain in phase III trial

US researchers have reported positive results of Phase 3 clinical trials of the non-opioid analgesic VX-548 in postoperative pain, according to a press release from developer Vertex Pharmaceuticals. The drug selectively inhibits Nav1.8 potential-dependent sodium channels, which are expressed in peripheral nociceptive neurons (predominantly in the spinal ganglion). It has previously demonstrated safety and efficacy in phase II trials. The Phase III included two randomized controlled double-blind supportive trials involving 1,118 adult patients who had undergone abdominoplasty or bunionectomy (removal of an "ossicle" on the foot). VX-548 was administered in the first two days after surgery (100 milligrams, then 50 milligrams every 12 hours orally) and compared to hydrocodone/acetaminophen (5/325 milligrams every six hours orally) and placebo.

It was found that the experimental drug, given the international generic name susetrigine, eliminated pain on the SPID48 and NPRS scales significantly more effectively than placebo after both surgical procedures (p < 0.0001 and p = 0.0002, respectively), but was not superior to the opioid analgesic (p = 0.2781 and p = 0.0016). VX-548 was well tolerated and there were no serious side effects. The results were considered successful, and the development company is preparing to submit an application for registration of the new drug to the FDA.