Long-Term Results of a Novel, Externally-Powered, Spinal Cord Stimulator for Chronic Pain (AUS nPower study)

ABSTRACT

Introduction: A novel spinal cord stimulation (SCS) system with a battery-free micro-implantable pulse generator (mIPG;Nalu Medical, Inc. CA, USA) is available for the treatment of intractable chronic pain. The system utilizes an external power source that bi-directionally communicates with the mIPG (∼1.5 cc volume). Methods: A prospective, multi-center clinical study was initiated to confirm the safety and performance of this novel system, in the treatment of trunk and limb intractable chronic pain. Specifically, subjects with leg(s) and/or back pain, meeting eligibility criteria were recruited and consented into the study. Subjects underwent a SCS trial utilizing a menu of therapy options, including tonic and the novel pulsed stimulation pattern (PSP) therapy. Eligible subjects received the permanent implant and were followed-up for up to 12-months from activation. Due to global COVID-19 restrictions, subjects were moved into a long-term follow-up (LTFU) phase, with study visits planned every 6-months, for an additional 2-years from their last visit. This reports on the long-term clinical and functional (depression, activities of daily living, overall change in quality of life) outcomes. The study was approved by an independent Ethics Committee and conducted in compliance with local regulations. Results: Twenty-five (25) intractable chronic back and/or leg pain subjects, using the PSP therapy, passed a screening and trial phase with ≥50% pain reduction in leg(s) and/or back and moved into the long-term implant phase of the study. Of these 25 subjects, 13 subjects have currently completed an average of 22-months follow-up;the average pain reduction was 73% (n=12) in the leg and 64% (n=11) in the back, from baseline to this time point. The responder rate (≥50% pain relief) was 92% in the leg (11/12) and 64% (7/11) in the back. In addition, all subjects wore the external power source via an adhesive clip and rated both its average comfort and ease of use as <1 on an 11-point scale (0=Very Comfortable, 10=Very Uncomfortable;0=Very Easy, 10=Very Difficult). The average percent improvement on the Beck’s Depression Inventory (BDI) was 40% (n=13) from screening to 22-months;the average improvement in Oswestry Disability Index (ODI) was 34% (n=13) at this time point. Sixty-nine percent (69%;9/13) of subjects indicated “very much improved” on the Patient Global Impression of Change. Conclusion: These results continue to demonstrate the favorable performance of this novel, battery-free, externally-powered micro-implantable SCS through 22-months post implantation. Further investigation is warranted to confirm these preliminary findings. Disclosure Paul Verrills, FAFMM GDMM (Hons) MM (Pain Medicine) FIPP AMA Abbott Consulting Fee Self, Abbott Speakers Bureau Self, Nalu Ownership Interest - Future Stock Options Self, Nalu Contracted Research Self, Nevro Contracted Research Self, Saluda Contracted Research Self, Nalu Speakers Bureau Self, Biotronik Consulting Fee Self, Presidio Contracted Research Self, John Salmon, MBBS None, Dan Bates, MBBS None, James Yu, MD None, Bruce Mitchell, MD None, Neels Du Toit, MBChB None, Matthew Green, MD None, Murray Taverner, MBBS None, Vahid Mohabbati, MD None, Peter Staats, MBA,MD Saluda Medical Consulting Fee Self, Grunenthal Royalty, Medtronic Fees for Non-CME/CE Services (e.g. advisor), electroCore Employee, SPR therapeutics Ownership Interest, Nalu Fees for Non-CME/CE Services (e.g. advisor), Gary Heit, MD, PhD Nalu Medical Inc Consultant Self, Robert Levy, MD, PhD Nalu Ownership Interest, Saluda Ownership Interest, James Makous, PhD Nalu Medical Consulting Fee, Nalu Medical Ownership Interest