Saluda Medical has announced The Lancet Neurology journal published results from the US pivotal study demonstrating its Evoke ECAP-controlled, closed-loop spinal cord stimulation (SCS) system provided long-term, statistically superior, and clinically meaningful pain relief for patients with chronic intractable back and leg pain out to 12 months compared to open-loop SCS.
The results generated in the US Evoke pivotal study demonstrate that the spinal cord response to stimulation can be successfully measured and used to adjust stimulation to maintain spinal cord activation within the patient-specific therapeutic window. The study establishes that the controlled level of spinal cord activation provided by closed-loop technology is associated with increased pain relief and positive clinical outcomes.
Evoke is the first closed-loop SCS system that measures the spinal cord’s response to stimulation (via ECAPs, or evoked compound action potentials) and adjusts on every pulse to optimize activation within the patient’s therapeutic window.
Nagy Mekhail, professor at the Cleveland Clinic Lerner College of Medicine, director of Evidence-Based Pain Medicine Research and Education in the Department of Pain Management at the Cleveland Clinic, and the first author of the publication, commented, “This study provides robust evidence of outcomes in the treatment of overall pain, with superior patient responder rates with closed-loop SCS compared to the open-loop SCS control group.
“Beyond the clinical results, this study has important practical implications as it establishes that individual-specific therapeutic windows can be identified and targeted to maintain spinal cord activation at therapeutic levels and improve care long term. In fixed-output and open-loop SCS systems, the amount of energy reaching the spinal cord continually fluctuates, faster than a patient can adjust with a remote, resulting in less time within the therapeutic window.
“Essentially, Evoke is designed to listen to the spinal cord, compare the spinal cord response to the target level chosen by the patient, and adjust stimulation in real-time to provide the optimum dose. We believe this is the first step for the field of neuromodulation to move toward an interactive, mechanism-based, individualised therapy founded on an objective outcome measure. This represents a significant opportunity to improve the success of neuromodulation for patients seeking chronic pain relief.”
Lawrence Poree, director, Neuromodulation Service, Division of Pain Medicine at University of California, San Francisco (UCSF), USA, and the senior author of the publication, added, “These are impressive clinical outcomes for comprehensively managing patients’ pain effectively over the long term. The more than 50% of closed-loop patients who reached high responder status of greater than or equal to 80% reduction in overall pain also demonstrated clinically meaningful changes in secondary patient-reported outcomes, emphasising the value of achieving this high threshold.
“As clinicians, we understand that functional disability, emotional functioning, sleep quality, quality of life, and global impression of change are all extremely important to patients in managing their pain. One of the most notable patient-reported outcomes of the Evoke study was the voluntary reduction or total elimination of opioids by more than half of patients treated with closed-loop SCS. We believe that publication in the top neurology journal both shows the advantage of closed-loop spinal cord stimulation and demonstrates how this promising new therapy may benefit patients.”
Key results published from the Evoke US pivotal study at 12 months include:
- Closed-loop SCS met the pre-specified primary endpoint.
- Closed-loop demonstrated statistically superior overall back and leg pain relief (with no increase in pain medications) compared to control with more than 80% (83.1% [49/59]) of closed-loop subjects achieving greater than or equal to 50% pain relief (open-loop: 61.0% [36/59]), (p=0.0060).
- Among subjects taking opioids at baseline, opioid use was reduced or eliminated in more than half of closed-loop patients (55% [17/31]) compared to 40% of open-loop patients (12/30).
- It was observed that closed-loop maintained spinal cord activation within the therapeutic window 95.2% of the time (47.9% of the time with open-loop).
- ECAP-controlled closed-loop SCS provided clinically notable improvement from baseline in other patient-reported outcomes and the improvement was greater in the closed-loop group compared to the open-loop group.
Results of the study through 3-months of follow-up were reported previously during multiple plenary and oral presentations by leading pain specialists at the International Neuromodulation Society (INS) 14th World Congress in Sydney.
John Parker, CEO of Saluda Medical, commented, “We are now reaching a major junction, similar to that of the evolution of the cardiac pacemaker, where for the first time, we can record and respond to patient’s individual spinal cord electrophysiology continuously and in real time, providing adjustments millions of times per day and faster than any patient can adjust or predict. We are very pleased with this publication and its implications for future clinical potential.”