Mainstay Medical announces the completion of all implants in the ReActiv8-B Study

Mainstay Medical International plc (“Mainstay” or the “Company”, Euronext Paris: MSTY.PA and Euronext Dublin: MSTY.IE), a medical device company focused on bringing to market ReActiv8®, an implantable restorative neurostimulation system to treat disabling Chronic Low Back Pain, announces the completion of all implants in ReActiv8-B, its US IDE clinical study.

A total of 204 patients were implanted in the study, reflecting the strength of interest in study participation. The implants were completed in accordance with the Company’s planned timeline and the Company expects to announce a full data readout towards the end of 2018.

Jason Hannon, CEO of Mainstay, said: “Completing all implants in the ReActiv8-B study is a significant step for Mainstay and represents continued momentum in our efforts to bring ReActiv8 to patients in the US. We remain on track to have full study data towards the end of 2018. I would like to thank the study participants and investigators for their participation -- we look forward to announcing the results of the study later this year.”

ReActiv8-B is an international, multi-centre, prospective, randomized, sham-controlled triple-blinded study with one-way crossover, conducted under an IDE from the US Food & Drug Administration (FDA). The study is intended to gather data in support of a pre-market approval (PMA) application to the FDA, a key step towards the commercialization of ReActiv8 in the US. The study utilizes an adaptive trial design, inclusive of an interim analysis. In December 2017 the Company announced a positive outcome of the interim analysis.

About Mainstay
Mainstay is a medical device company focused on bringing to market an innovative implantable restorative neurostimulation system, ReActiv8®, for people with disabling Chronic Low Back Pain (CLBP). The Company is headquartered in Dublin, Ireland. It has subsidiaries operating in Ireland, the United States, Australia, Germany and the Netherlands, and is listed on the regulated market of Euronext Paris (MSTY.PA) and the ESM of Euronext Dublin (MSTY.IE).

About Chronic Low Back Pain
One of the recognized root causes of CLBP is impaired control by the nervous system of the muscles that dynamically stabilize the spine in the low back, and an unstable spine can lead to back pain. ReActiv8 is designed to electrically stimulate the nerves responsible for contracting these muscles and thereby help to restore muscle control and improve dynamic spine stability, allowing the body to recover from CLBP.

People with CLBP usually have a greatly reduced quality of life and score significantly higher on scales for pain, disability, depression, anxiety and sleep disorders. Their pain and disability can persist despite the best available medical treatments, and only a small percentage of cases result from an identified pathological condition or anatomical defect that may be correctable with spine surgery. Their ability to work or be productive is seriously affected by the condition and the resulting days lost from work, disability benefits and health resource utilization put a significant burden on individuals, families, communities, industry and governments.

Further information can be found at www.mainstaymedical.com

CAUTION – in the United States, ReActiv8 is limited by federal law to investigational use only.