Saluda Medical has announced that it has received full approval from the US Food and Drug Administration (FDA) for the Evoke spinal cord stimulation (SCS) system, which is indicated 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.
According to the company, Evoke is the first and only available SCS system capable of instantaneously reading, recording, and responding to evoked compound action potentials (ECAPs)—the nerves’ response to stimulation—to provide precise, continually optimised therapy.
The Evoke system is designed to maintain optimal pain inhibition by adjusting therapy more than 100 times per second.1 The firm says that it also captures and records millions of data points per day to provide clinical teams with unparalleled neurophysiological insights in the context of therapy performance.
Saluda states that this is the first premarket approval based on a double-blind randomised controlled trial, the EVOKE study, for an SCS system.
Nagy Mekhail (Cleveland Clinic, Cleveland, USA), lead author and medical monitor for the EVOKE study, said: “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. 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.
“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 Norman Shealy developed the first spinal cord stimulation device in 1967.”
The EVOKE study demonstrated superior pain relief with the system compared to open-loop SCS at 12 months, with no increase in pain medication (p=0.006). Nearly 90% of subjects implanted with Evoke† met the primary endpoint at 12 months, which was statistically superior to open-loop SCS (p=0.039), according to Saluda.
The percentage of Evoke† patients that demonstrated clinically meaningful improvements at 12 months were as follows2:
- Disability (Oswestry Disability Index [ODI]), 78.2%
- Mood (Profile of Mood States [POMS]), 70.9%
- Sleep (Pittsburgh Sleep Quality Index [PSQI]), 76.4%
- Health-related quality of life (European Quality of Life [EQ-5D]), 85.5%
Evoke† maintained spinal cord activation within the therapeutic window 95.2% of the time, versus 47.9% with open-loop SCS.
In addition, 24-month EVOKE study data recently published in JAMA Neurology show that the clinical outcomes were durable at 24 months, with zero explants due to loss of efficacy.3 Reprogramming was also practically eliminated between 12 and 24 months.3,4
Timothy Deer (Spine and Nerve Center of The Virginias, Charleston, USA), clinical investigator of the study, commented: “The FDA approval of the Evoke system marks a seminal moment in the field of spinal cord stimulation.
“For the last 50 years, our field has relied on subjective feedback from the patient to optimise therapy with results in published literature demonstrating good clinical outcomes, but also highlighting challenges with predictable long-term durability. I have seen first-hand 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.”
Saluda plans to implement a controlled, limited release of the Evoke system in the second half of 2022 among select trial sites before initiating a full commercial release in 2023.
† Indicates Evoke closed-loop spinal cord stimulation.
1. Stimulation adjustments are made at the same rate of frequency; mean frequency for EVOKE Study patients at 12-months was 37.7 Hz for closed-loop and 38.8 Hz for open-loop. 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 Neurol. 2020;19(2):123-134.
2. Secondary endpoints were not prespecified and were not adjusted for multiplicity.
3. Mekhail N, Levy RM, Deer 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. 2022;79(3):1-10.
4. Median (IQR) number of visits per patient per month between 12- and 24-months follow-up was 0.0 (0.0-0.1).