Effectiveness and Tolerability of a Moderate Dose of Tapentadol Prolonged Release for Managing Severe, Chronic Low Back Pain with a Neuropathic Component: An Open-label Continuation Arm of a Randomized Phase 3b Study

ObjectiveTo evaluate the effectiveness and tolerability of tapentadol prolonged release (PR) for severe, chronic low back pain with a neuropathic component in a subpopulation that achieved adequate pain relief with tapentadol PR 300mg/day in a randomized, double-blind, phase 3b study. MethodsPatients with painDETECT unclear or positive ratings and pain intensity 6 (11-point NRS-3 [average 3-day pain intensity]) were titrated to tapentadol PR 300mg/day over 3weeks. A subpopulation with pain intensity <4 continued receiving tapentadol PR 300mg/day during an 8-week, open-label continuation arm. For the primary study population, patients with 1-point decrease from baseline and pain intensity 4 were randomized to tapentadol PR 500mg/day or tapentadol PR 300mg/day plus pregabalin 300mg/day during a concurrent 8-week, double-blind comparative period. ResultsFrom baseline to end of titration and to final evaluation, significant improvements were observed in pain intensity (mean [SD] changes from baseline to: end of titration; -5.3 [1.78]; final evaluation; -5.2 [2.39]; both P<0.0001), neuropathic pain symptoms, and quality-of-life measures in the open-label continuation arm, with greater improvements in this selected subpopulation than in either group in the primary study population. A favorable tolerability profile was observed, with incidences of all individual treatment-emergent adverse events5.1% during the continuation period. ConclusionsA subpopulation of patients with low back pain with a neuropathic component responded very well to tapentadol PR 300mg/day, with significant improvements in pain intensity, neuropathic pain-related symptoms, and quality of life. Further research is needed to identify factors associated with a very positive treatment response.