Pain Outcomes from the COMFORT 2 RCT for Peripheral Nerve stimulation-12-month Results

Introduction: 3 and 6-month results from a second in a series of landmark Randomized Clinical Trials (COMFORT 2 RCT) were published (1) leading to Level 1 evidence on Peripheral Nerve Stimulation (PNS) with a battery-free, non-integrated micro-implantable pulse generator (micro-IPG). The study is ongoing and will continue to collect long-term data to document effectiveness of PNS over Conventional Medical Management (CMM). We are reporting 12-month pain outcomes from this ongoing study. The COMFORT 2 study is funded by the manufacturer.

Methods: COMFORT 2 RCT (2) is a post-market, open-label, multicenter study designed to align with standard of care procedures for PNS. Eligible subjects were consented, and prescribed PNS therapy to treat chronic pain in the shoulder, knee, low back, or foot/ankle. Subjects were randomized to active (PNS+CMM) and control (CMM only) arms in a 2:1 ratio. Subjects who completed a successful trial (≥ 50% pain relief from baseline) were implanted with the permanent device. Subjects in both arms will be followed out to 36 months at 3-to-6-month intervals, with subjects in the control arm eligible to cross-over at 3-months. Pain scores were collected using the Numeric Rating Scale (NRS 0-10; 0-no pain, 10-wort possible pain). IRB approval was received prior to commencement of study activities

Results: 185 subjects were randomized in the study, 121 in Active Arm and 64 in the Control Arm, with subjects in various stages of follow-up. Primary outcomes at 3 months were published (1) with the active arm (PNS + CMM) showing superiority over the control arm (CMM; p< 0.001). The results at 12-months continue to align with initial results at 3 and 6 months (1), with subjects in the Active Arm, receiving an average pain relief of 70% when compared to baseline. The average pain score improved from 7.5 ± 1.2 at baseline to 2.3 ± 1.8 at 12-months (p < 0.001). The responder rate at 12 months was 85% with 45 of the 53 subjects showing ≥ 50% pain relief from baseline. The high responder rate (≥ 80% pain relief) was 34% (18/53).

Conclusion: Interim results at the 12-month timepoint demonstrate that subjects receiving PNS therapy along with CMM report statistically significant levels of pain relief and are consistent with published 3- and 6-month outcomes1. Additional data from this study will be reported as available