Boston Scientific has announced a $1.5bn investment to acquire approximately a 34% equity stake in MiRus, a company developing the SIEGEL Balloon Expandable transcatheter aortic valve replacement (TAVR) system.
According to the agreement, Boston Scientific also secured an exclusive option to acquire the MiRus TAVR system, subject to further payments and milestone achievements.
Featuring a rhenium alloy, the SIEGEL technology is said to be the first nickel-free, balloon-expandable TAVR valve designed to restore the function and facilitate normal blood flow in severely narrowed aortic valves.
The SIEGEL TAVR valve utilises dry porcine tissue leaflets and a nitric oxide-coated rhenium frame with radial strength exceeding cobalt or titanium.
The frame’s open-cell design is intended to prevent foreshortening and facilitate precise heart placement.
All valve sizes (23mm, 26mm, and 29mm) can be delivered via an 8-Fr expandable sheath, nearly 50% smaller than current commercial TAVR sheaths, which may reduce vascular injuries.
Recently, MiRus initiated the STAR pivotal trial, studying the effectiveness and safety of the three SIEGEL valve sizes in up to 1,025 patients with severe, symptomatic aortic stenosis at varying surgical risk levels.
MiRus had presented early feasibility study data last year.
Boston Scientific may exercise its option to acquire MiRus’ TAVR business for an additional $3bn upon achievement of specified clinical and regulatory milestones, resulting in full ownership.
MiRus may further receive payments based on SIEGEL TAVR valve net sales, and Boston Scientific retains an exclusive option to acquire mitral and tricuspid replacement valve assets from MiRus.
Boston Scientific interventional cardiology and vascular therapies executive vice-president and president Lance Bates said: “The occurrence and recognition of aortic stenosis is growing rapidly, and our investment in MiRus continues our pursuit to bring a differentiated TAVR system into our portfolio that we anticipate may improve outcomes for patients living with this life-threatening disease.
“Built upon years of research and proprietary technology, we believe the distinctive design and impressive early clinical results of the SIEGEL valve may set it apart from currently available technology, potentially providing physicians an advanced option to treat a wide array of patients.”
In March 2026, Boston Scientific received 510(k) clearance from the US Food and Drug Administration (FDA) for its Asurys fluid management system, developed to provide irrigation and distention while carrying out endoscopic urologic procedures such as ureteroscopy.
