Irish back pain group Mainstay Medical raises €115m to fund expansion

Two new investors lead funding round as company looks to accelerate commercial rollout in key US market as well as Europe and Australia

Irish back pain specialist Mainstay Medical has raised $125 million (€115.3 million) in its biggest equity fundraising to date as it looks to accelerate the company’s expansion across US, European and Australian markets.

The Dublin-based group’s ReActiv8 is designed to treat chronic lower back pain. The device is implanted in a surgical procedure and works by electrically stimulating nerves in muscles supporting the lower spine.

Two new investors in the group, Gilde Healthcare and Viking Global Investors, led the funding round with other significant existing investors, including Ally Bridge Group, Sofinnova Partners (Crossover Fund), Irish-based Fountain Healthcare Partners, and Perceptive Advisors, also taking part. Other investors in the business include the Irish Strategic Investment Fund and KCK Group.

“We are excited to lead this financing and to work with Mainstay to continue to unlock the potential of ReActiv8 therapy,” said Geoff Pardo, partner at Gilde Healthcare, the Utrecht-based Dutch investor managing €2.5 billion. “Patients with mechanical chronic low back pain have had very limited treatment options, and the restorative mechanism of action offered by ReActiv8 is both unique and very promising.”


Mr Pardo, who focuses on Gilde’s US investments and is based in Boston, will join the Mainstay Medical board of directors.

Mainstay secured approval to sell its device in the US market in 2020, four years after securing initial European approval. The company has subsidiaries operating in Ireland, the United States, Australia, Germany and the Netherlands.

Viking says it has more than $46 billion invested across public and private companies. Apart from financing group expansion, Mainstay said the new funding would be used for additional post-market clinical studies and research, and general operations.

Mainstay chief executive Jason Hannon said the new funds would allow the company continue its “rapid commercial growth” as well as working with health insurers in the US to cover the procedure.

“A financing of this magnitude will allow us to accelerate our efforts to revolutionise the treatment of mechanical low back pain,” he said. “We are now strongly capitalised to execute on our corporate objectives.

“In addition to commercial expansion in our target markets, these objectives include the generation of additional clinical and health economic data to further demonstrate that ReActiv8′s purpose-built, restorative approach to the treatment of mechanical chronic low back pain is superior to competitive therapies originally designed for other indications, as well as the continued development and enforcement of our dominant intellectual property portfolio,” he added.

The company estimates that there are about two million people in the EU and the US who could be candidates for ReActiv8. It estimates the market for disabling chronic lower back pain in patients not suitable for surgery is worth approximately $30 billion.

The funding, the company’s first equity fundraise since April 2021, brings the total amount it has raised to date to just shy of $400 million, according to Crunchbase. Mainstay also agreed debt financing of up to $50 million with Madryn Health Partners in September 2022, of which $30 million was used to pay back maturing debt.

Dominic Coyle

Dominic Coyle

Dominic Coyle is Deputy Business Editor of The Irish Times