FDA Approves Saluda’s Evoke Spinal Cord Stimulation System for Chronic Intractable Pain

Nagy Mekhail, MD, PhD

According to a new announcement, the FDA has approved the Evoke Spinal Cord Stimulation (SCS) System (Saluda Medical) for the treatment of chronic intractable pain of the trunk and/or limbs, including unilateral or bilateral pain associated with failed back surgery syndrome, intractable low back pain, and leg pain. The company plans to implement a controlled, limited release of the system in the second half of 2022 among selected sites before full commercial release in 2023.¹

Designed to maintain optimal pain inhibition through adjusting therapy more than 100 times per second, the Evoke System also captures and records millions of data points per day to help guide clinical teams and keep them informed on the therapy’s performance. With the approval, the system becomes the first and only available SCS system capable of instantaneously reading, recording, and responding to evoked compound action potentials (ECAPS), or the nerves that respond to stimulation, to provide more optimized performance.

The basis for the approval comes from the double-blind, randomized EVOKE study (NCT02924129), which demonstrated Evoke System’s superiority to open-loop SCS in treating overall back and leg pain. In the closed-loop arm of the study, greater improvements in clinical outcomes coincided with more consistent spinal cord activation within subjects’ therapeutic window.

"The groundbreaking technology behind the Evoke System's ability to intelligently measure spinal cord activation has had many of us excited for a long time," lead investigator Nagy Mekhail, MD, PhD, professor, and director, Evidence-Based Pain Medicine Research and Education, Cleveland Clinic, said in a statement.¹ "More exciting than the technology, though, is the unparalleled quality of the evidence backing this system which demonstrates pain relief coupled with clinically significant improvements in physical and emotional functioning, sleep quality, and health-related quality of life."

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"This evidence gives me confidence that Evoke is well-suited to address the unmet need of providing long-term, durable pain relief with this therapy. Simply put, this is one of the most important innovations in the field of Neuromodulation since Dr. Norman Shealy developed the first spinal cord stimulation device in 1967," Mekhail added.

The pivotal EVOKE study randomized 134 patients with chronic, intractable pain of the back and legs 1:1 to ECAP-controlled, closed-loop SCS or fixed-output, open-loop SCS. The same neuromodulation system (Evoke System) served as the investigational and control device, as it offered both ECAP-controlled closed-loop SCS and open-loop SCS.

The intention-to-treat analysis comprised of 125 patients at 3 months and 118 patients at 12 months (closed-loop: n = 59; open-loop: n = 59). At 3 months, the primary outcome, proportion of patients with at least a 50% reduction in overall back and leg pain, was achieved by 82.3% (n = 51) of those in the closed group compared with 60.3% (n = 38) in the open-loop group (difference, 21.9%; 95% CI, 6.6-37.3; P = .0052). This statistically significant difference was also observed at 12 months as well in the original analysis (closed-loop: 83.1%; open-loop: 61.0%; difference, 22.0%; 95% CI, 6.3-37.7; P = .0060).²

"The FDA approval of the Evoke System marks a seminal moment in the field of spinal cord stimulation," Timothy R. Deer, MD, president and chief executive officer, Spine and Nerve Center of The Virginias, and clinical investigator, said in a statement.¹ "For the last 50 years, our field has relied on subjective feedback from the patient to optimize therapy with results in published literature demonstrating good clinical outcomes, but also highlighting challenges with predictable long-term durability. I've seen firsthand the clinical benefits of tightly controlling stimulation by measuring the body's neurophysiological response and how this pioneering closed-loop technology is redefining the SCS experience for patients and clinicians."

On patient-reported outcomes (PROs), 78.2% and 70.9% of patients, respectively, demonstrated clinically meaningful improvements on disability (Oswestry Disability Index) and mood (Profile of Mood States) at 12 months after treatment with the Evoke System. Furthermore, 76.4% and 85.5% of these patients, respectively, also demonstrated clinically meaningful improvements at 12 months on PROs such as sleep (Pittsburgh Sleep Quality Index) and health-related quality of life (European Quality of Life).

Earlier this year, Saluda published a secondary analysis that included 24-month outcomes from the trial. At 24 months, significantly more closed-loop than open-loop patients were responders in overall pain (closed-loop: 79.1% vs open-loop: 53.7%; difference, 25.4%; 95% CI, 10.0-40.8; P = .001). The safety profiles between these arms did not differ (difference in rate of study adverse events: 6.0; 95% CI, –7.8 to 19.7).³

Jim Schuermann, president and chief executive officer, Saluda, said in a statement, "FDA approval for the Evoke System is a significant milestone for Saluda – one resulting from over a decade of advanced research and development and years of patient-centric determination to transform the standard of care. Evoke's innovations are born from John Parker's vision and pioneering research, and Saluda's strong and lasting partnerships with the clinical community and mutual dedication to patients."¹

REFERENCES
1. Saluda Medical receives FDA approval for the Evoke Spinal Cord Stimulation System to treat chronic intractable pain. News release. Saluda Medical. March 8, 2022. Accessed March 9, 2022. https://www.prnewswire.com/news-releases/saluda-medical-receives-fda-approval-for-the-evoke-spinal-cord-stimulation-system-to-treat-chronic-intractable-pain-301497815.html

2. Mekhail N, Levy RM, Deer TR, et al. Long-term safety and efficacy of closed-loop spinal cord stimulation to treat chronic back and leg pain (Evoke): a double-blind, randomized, controlled trial. Lancet Neruol. 2020;19(2):123-134. Doi:10.1016/S1474-4422(19)30414-4

3. Mekhail N, Levy RM, Deep TR, et al. Durability of clinical and quality-of-life outcomes of closed-loop spinal cord stimulation for chronic back and leg pain: a secondary analysis of the Evoke randomized clinical trial. JAMA Neurol. Published online January 8, 2022. doi:10.1001/jamaneurol.2021.4998