Inari FlowTriever Achieves Primary Endpoint in Pivotal PEERLESS Trial for Pulmonary Embolism

Inari Medical recently announced positive results from the prospective PEERLESS trial of its FlowTriever system.

The company designs FlowTriever. The system treats pulmonary embolism (PE). FlowTriever removes blood clots from peripheral vessels in a non-surgical manner. Its applications include the treatment of PE and thrombus in right atrial transport. It received FDA 510(k) approval in 2018.

The latest research from Inari, headquartered in Irvine, California, compared FlowTriever with Catheter-Directed Thrombolysis (CDT). The results were presented by Co-Principal Investigator Dr. Wissam Jaber at the 2024 Transcatheter Cardiovascular Therapeutics (TCT) conference held in Washington, D.C.

PEERLESS achieved its primary composite endpoint, due to the comparison with CDT,FlowTriever patients experienced significantly less clinical deterioration or treatment escalation, reduced ICU admissions, and shorter ICU stays. Patients also showed faster clinical and hemodynamic recovery, shorter hospital stays, and lower 30-day readmission rates.

"These results are crucial for guiding optimal PE treatment decisions, providing strong evidence that FlowTriever can reduce clinical deterioration and the need for re-intervention through more effective early thrombus resolution. As the only randomized trial evaluating mechanical thrombectomy for PE, PEERLESS allows us to confidently say now that FlowTriever treatment is safe, effective, and superior to CDT," said Dr. Jaber.

PEERLESS enrolled 550 intermediate-risk PE patients across 57 centers globally. Patients were randomized to receive either FlowTriever thrombectomy or CDT. The primary cohort excluded patients with absolute contraindications to thrombolytic drugs and included a small number of patients with relative contraindications.

Compared with CDT, the number of clinical deteriorations and/or treatment escalations in FlowTriever patients was reduced by 3 times. They also demonstrated greater improvements in clinical symptoms and hemodynamics, as well as lower 24-hour and 30-day readmission rates to accelerate recovery.

In addition, Inari stated that the ICU admission rate, ICU stay, and hospital stay for FlowTriever patients were significantly reduced. The number of patient deaths in the FlowTriever group at discharge or within 7 days was zero, with zero cases of deterioration associated with cardiac arrest, high-grade atrioventricular block, or respiratory failure, and the all-cause mortality rate at 30-day follow-up was as low as 0.4%.

Thomas Tu, MD, Chief Medical Officer of Inari, stated: "PEERLESS is the first large-scale randomized PE study in over a decade, reaffirming our commitment to practice-changing and guideline-shaping research while setting a new standard for clinically meaningful endpoints. The results of this study position FlowTriever as the primary interventional tool for intermediate-risk PE. PEERLESS is the first of a series of randomized controlled trials unveiled by Inari and others, ushering in a golden age of PE research."

The FlowTriever system is a large-bore device that mechanically engages thrombi in the pulmonary artery via a self-expanding nitinol disk. As the large-bore catheter aspirates, the nitinol disk retracts into the catheter, entraining the thrombus. The device can directly remove thrombi without the need for adjunctive thrombolytic drugs. Currently, only the EkoSonic Endovascular System and the FlowTriever system are FDA-approved for acute PE treatment, while other devices are seeking FDA approval for related indications.

Inari's products have significant advantages and perform well in the market: Currently, it is the only interventional device suitable for large thrombi. Mechanical thrombectomy allows immediate vessel opening, reducing patient hospital stays; no thrombolytic drugs are needed, avoiding drug-related complications.

Thrombectomy time is independent of thrombus length, improving thrombectomy efficiency, reducing operation time and treatment costs; the product's surgical method and principle have gained authoritative recognition in the U.S. through large-scale clinical trials.

Inari Medical was founded in 2011, with its headquarters located in California, USA. The company's two products are both innovative minimally invasive mechanical thrombectomy platforms: ClotTriever: used for deep vein thrombosis (DVT) treatment, and received FDA approval in February 2017.

FlowTriever: Used for pulmonary embolism (PE) treatment, received FDA approval in May 2018.

This Issue's Planning: Shen Li

Editor-in-Chief: Chen Baolin

Author of this article: Yun Ye Xuan

Post-production:Ling Wujuan