Rox Medical said today that it raised a $40 million Series E round for the stent-like Coupler device it developed to treat hypertension by connecting the femoral artery and the femoral vein.

The round was led by the Novartis Venture Fund and Apple Tree Partners, with participation from prior backers Versant Ventures and Domain Associates, San Clemente, Calif.-based Rox said.

“This financing is a significant milestone for Rox Medical,” CEO Rodney Brenneman said in prepared remarks. “Building on our best-in-class data published in The Lancet in 2015, we will soon initiate a U.S. pivotal clinical trial of the Rox Coupler therapy for patients in need of alternative solutions for uncontrolled hypertension.”

David McIntyre and Sami Hamade of Apple Tree Partners and Steven Weinstein of Novartis Venture Fund are slated to join the Rox Medical board as part of the funding round, the company said.

“We are excited to join this innovative and differentiated effort in the hypertension field. Despite best medical therapy, many patients still have uncontrolled hypertension which contributes to significant morbidity and mortality,” Weinstein added.

“Rox has the potential to solve many challenges with their revolutionary device by providing instantaneous and predictable outcomes for patients and physicians. The company is now well-positioned for success in this late clinical phase of development,” McIntyre said.

Back in 2014, Brenneman told MassDevice.com that Rox, a Stanford spinout established in 2004 to pursue several indications including chronic obstructive lung disease and heart failure, noticed a dramatic effect on high blood pressure in COPD patients implanted with the device. That inspired a small, 8-patient feasibility study to examine the device in hypertensive patients without COPD that delivered “compelling” results, Brenneman told us.

After the painless, hour-long procedure, “we can hook a pressure transducer up to the arterial line and immediately see a blood pressure drop,” he said.

“It’s very repeatable and you know, on the table in the cath lab, that you just achieved the blood pressure drop,” he said. “By the time they leave the hospital, the next day – typically in Europe they keep them over 1 night – we’ll measure their blood pressure and they’re already showing a drop, so you basically send someone out the door with an improvement.”

Including the Series E round, Rox has raised about $95 million in venture capital backing over the past 12 years, undergoing a re-tooling as the VC world consolidated and Rox decided to focus on the hypertension indication, Brenneman said. Initial backers included Versant and Domain, plus Prism VentureWorks and Essex Woodlands.