Mainstay Medical Holdings plc announced that the U.S. Food and Drug Administration (FDA) has approved the company’s Premarket Approval (PMA) application for ReActiv8®, its implantable neurostimulation system to treat intractable chronic low back pain. The FDA approval grants Mainstay the right to market ReActiv8 in the United States as an aid in the management of intractable chronic low back pain associated with multifidus muscle dysfunction, as evidenced by imaging or physiological testing in adults who have failed therapy, including pain medications and physical therapy, and are not candidates for spine surgery. The FDA approval of ReActiv8 is primarily based on results from the ReActiv8-B clinical study, a pivotal 204-patient, international, multi-center, prospective, randomized, active sham-controlled, blinded trial with one-way cross-over, conducted under an Investigational Device Exemption (IDE) from FDA. Based on the FDA approval, Mainstay is refining its commercial launch plans for ReActiv8 in the U.S., including the build out of the commercial team, inventory procurement and related matters, as well as evaluating the financial resources necessary to fund its planned activities. Mainstay intends to host an investor event later this year to provide an update on its commercial plans for ReActiv8. ReActiv8 is an active implantable medical device designed to treat people with chronic low back pain (CLBP). ReActiv8 provides bilateral electrical stimulation of the L2 medial branch of the dorsal ramus nerve as it crosses the transverse process at L3. This nerve supplies the lumbar multifidus muscle, a key stabilizing muscle of the low back. Reactiv8’s stimulation of the nerve elicits contraction of the muscle, which can lead to improvement in CLBP and its disabling effects. Low back pain is the number one cause of years lived with disability worldwide and a leading cause of activity limitation and work absence throughout much of the world, imposing a high economic burden on individuals, families, communities, industry and governments. While treatment options exist for patients with CLBP of a predominantly neuropathic origin, for the large portion of patients whose pain is predominantly nociceptive (or mechanical) in nature there are few therapies beyond drugs and injections, both of which merely mask the pain. ReActiv8 is intended for those patients without indications for spine surgery or spinal cord stimulation and who have continuing pain despite medical management. The Company currently estimates that there are approximately two million people in the EU and the U.S. who could be candidates for ReActiv8. ReActiv8 has a CE Mark allowing for commercialization in the European Economic Area and has been focused on building clinical validation in Germany in select centers ahead of wider commercial availability in the future. ReActiv8 has also been admitted to the Australian Register of Therapeutic Goods (ARTG), enabling commercialization throughout Australia, and has been approved for inclusion on the Protheses List of reimbursed products in Australia, effective as of 1 July 2020. The Prostheses List identifies implantable devices eligible for reimbursement from all private health insurance funds in Australia. In the U.S., ReActiv8 is FDA approved, and the Company plans to commercially launch in early 2021.