Terumo Interventional Systems had introduced the Misago RX self-expanding peripheral stent to the US market at the 2015 Society for Vascular Surgery Annual Meeting (SVS; 17–20 June, Chicago, USA).
The Misago stent system consists of a nitinol stent pre-mounted on the distal portion of a rapid-exchange delivery catheter. Designed and developed in Japan, it is now available to treat patients in the USA with peripheral artery disease in the superficial femoral artery (SFA) and/or proximal popliteal artery.
The Misago stent has been available outside of the USA since 2008. It has been studied in more than 5,000 patients in numerous clinical trials. The US Food and Drug Administration (FDA) granted premarket approval for the device in May. FDA approval was based on submission of one-year data from OSPREY (Occlusive/stenotic peripheral artery revascularization study), a single-arm, multicentre, non-randomised prospective clinical trial for the treatment of atherosclerotic stenosis and occlusions of the SFA. In one of the first “harmonisation by doing” initiatives between the USA and Japan, the study included patients enrolled in the USA, Japan, Taiwan and Korea.
“The lack of differences in outcomes among the patients studied supports the validity of multi-national trials which will streamline approvals in different nations and maximise resources while reducing costs. I can foresee future trials which build upon our harmonisation study design” said Takao Ohki, chief primary investigator for the international trial.
Data from the OSPREY study demonstrated the following:
- The flexible, durable design offers a low potential for stent fracture. In the OSPREY trial there was a 0.9% incidence of stent fracture per stent at 12 months post-procedure.
- A simplified thumbwheel system allows for precision deployment by a single operator at the lesion site. Physicians in the OSPREY study reported 100% success in delivering Misago to the lesion site.
- Sustained patency of 82.9% as measured at one-year using Kaplan-Meier analysis (PSVR of less than or equal 2.4).
- 88.6% per cent freedom from target lesion revascularisation, as measured at one-year using Kaplan-Meier analysis.
“The MISAGO stent has a flexible design and good radial force that we found performed well in the superficial femoral artery” said John Fritz Angle, principal investigator for the US clinical trial. “Peripheral artery disease can have devastating consequences but we believe the Misago stent offers a durable treatment option for superficial femoral artery disease.” Angle presented the results of the OSPREY study at the SVS Meeting.
“We look forward to partnering with the US interventional medical community to bring the benefits of this novel technology, as well as others in the future, to patients in the US,” said Chris Pearson, vice-president marketing at Terumo Interventional Systems. “We express our gratitude to all the OSPREY investigators that helped to advance the scientific knowledge of the Misago stent.”