MiRus is developing the investigational SIEGEL balloon-expandable TAVR system, designed with a proprietary nitric oxide–coated rhenium alloy to provide a nickel-free valve construct. The SIEGEL valve features an open-cell frame intended to eliminate foreshortening for more precise placement, dry porcine tissue leaflets, and can be delivered through an 8 French expandable sheath across 23 mm, 26 mm, and 29 mm sizes. The device remains investigational and has not been approved for commercial distribution; MiRus has presented early feasibility data and recently launched the STAR pivotal trial enrolling up to 1,025 patients at varying surgical risk levels. The company is working with an Atlanta-based team and reported enthusiastic investigator feedback on delivery and hemodynamics. Financially, MiRus secured a $1.5 billion strategic investment from Boston Scientific that conveys a ~34% stake and includes options and milestone-linked payments that could total several billion dollars tied to clinical, regulatory, and sales milestones.

Total raised

$1.6B

Funding rounds

2

Latest round

Equity

Latest activity

May 2026