Phase 3 study evaluates tolperisone for back spasm pain

A phase 3, double-blind, randomized, placebo-controlled study is evaluating tolperisone in patients experiencing pain from acute muscle spasms in their back, according to a poster presentation at this year’s virtual PAINWeek meeting.

“Currently, there is a high unmet medical need for those affected by acute muscle spasms of the back due to little research within the last few decades,” Randall E. Kaye, MD, chief medical officer at Neurana Pharmaceuticals, told Healio Primary Care.

“Tolperisone is non-opioid, centrally acting muscle relaxant that is being developed by Neurana Pharmaceuticals, Inc. for the relief of acute and painful muscle spasms of the back without the drowsiness and cognitive function impairment commonly seen with other muscle relaxants,” Kaye said.

In a recently completed phase 2 study, tolperisone was found to be effective in relieving back spasm pain compared with placebo in various doses, with the 200 mg dose demonstrating the highest efficacy. Researchers also found that tolperisone was well-tolerated and had similar treatment-related adverse effects as placebo.

The phase 3 study will be conducted at multiple centers; adults aged 18 to 64 years with pain from acute muscle spasms of the back will be randomly assigned to receive 100 mg of tolperisone, 200 mg of tolperisone or placebo for 14 days.

To be eligible, participants will need to have experienced pain and stiffness from muscle spasms starting within 7 days of entering the study and at least 8 weeks after their previous back pain episode. They must also have a self-reported pain “right now” numerical rating scale score — with zero indicating no pain and 10 indicating greatest possible pain — of four or greater at baseline.

During the study, which will enroll 750 participants at approximately 60 clinical sites across the U.S. beginning in October, participants can receive 500 mg of acetaminophen as a rescue medication and document their daily use through day 14.

The study’s primary endpoint is participants’ pain “right now” score after 2 weeks. As secondary endpoints in the study, researchers will also evaluate participants’ onset of action, time to pain relief, patients’ impression of change and disability.

“As tolperisone may also have an analgesic potential, it is possible that co-prescribing could be reduced with tolperisone if approved,” Kaye said. “As such, tolperisone, in addition to potential being the first novel, non-opioid treatment in the U.S. for acute and painful muscle spasms without causing drowsiness or impacting cognitive function, may also reduce the need for opioid or steroid prescriptions.”