Boston Scientific announced a $1.5 billion strategic investment in MiRus in exchange for an approximately 34% equity stake in the privately held medical technology company. The agreement also gives Boston Scientific an exclusive option to acquire MiRus’ investigational SIEGEL Balloon Expandable Transcatheter Aortic Valve Replacement (TAVR) system, subject to additional milestone-based payments and regulatory achievements.
The SIEGEL valve is designed with a proprietary nitric oxide-coated rhenium alloy and is the first nickel-free, balloon-expandable TAVR valve intended to restore blood flow in patients with severely narrowed aortic valves due to aortic stenosis. The system is being developed to treat cardiovascular disease with a focus on less invasive delivery and improved precision during implantation.
Boston Scientific said the investment aligns with its strategy to expand its structural heart portfolio and bring differentiated TAVR technology to physicians and patients. The company highlighted the valve’s early clinical performance, including its open-cell frame design intended to eliminate foreshortening and support more precise placement in the heart.
The valve also features dry porcine tissue leaflets and can be delivered through an 8 French expandable sheath across all available sizes, 23 mm, 26 mm, and 29 mm. According to the companies, the sheath size is approximately 50% smaller than currently commercially available TAVR delivery sheaths, which could help reduce vascular injuries during procedures.
MiRus recently launched the STAR pivotal trial, which is evaluating the safety and effectiveness of the SIEGEL valve in up to 1,025 patients with severe symptomatic aortic stenosis. The study includes patients considered to be at low, intermediate, or high risk for surgical complications. The company previously presented early feasibility study findings evaluating the device’s safety and performance.
Under the agreement, Boston Scientific may exercise its option to acquire the MiRus TAVR business through additional aggregate cash payments totaling $3 billion after certain clinical and regulatory milestones are achieved. If exercised, the transaction would provide Boston Scientific with full ownership of the TAVR business. MiRus would also be eligible for additional payments tied to future net sales of the SIEGEL valve. The agreement further includes an exclusive option for Boston Scientific to acquire MiRus’ mitral and tricuspid replacement valve assets through an additional payment.
Boston Scientific said the investment is expected to be immaterial to adjusted earnings per share in 2026.
The SIEGEL Balloon Expandable Transcatheter Aortic Valve Replacement system remains an investigational device and has not yet been approved for commercial distribution in any country.
KEY QUOTES:
“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.”
Lance Bates, Executive Vice President And President, Interventional Cardiology And Vascular Therapies, Boston Scientific
“The SIEGEL valve is a promising technology and has received enthusiastic feedback from physician investigators for its less invasive delivery, nickel-free construct, precise placement resulting from a lack of foreshortening and excellent hemodynamics. This collaborative relationship with Boston Scientific alongside the exceptional capabilities of our Atlanta-based team can further accelerate our progress towards broad accessibility for patients and physicians for what we believe will be a transformational treatment.”
Jay Yadav, M.D., Founder And Chief Executive Officer, MiRus
