November 29, 2023 — Inari Medical, Inc., a medical device company with a mission to treat and transform the lives of patients suffering from venous and other diseases, today announced the first patient enrollment in the PEERLESS II study. This prospective, global, multi-center randomized controlled trial (“RCT”) compares the outcomes of intermediate-risk acute pulmonary embolism (“PE”) patients treated with the FlowTriever System against those treated with traditional anticoagulation therapy alone. The first patient was enrolled by Dr. William H. Matthai, Jr., Director of Clinical Cardiology Research and Professor of Clinical Medicine (Cardiovascular Medicine) at Penn Presbyterian Medical Center at the University of Pennsylvania.
"PEERLESS II is challenging the most commonly administered first-line therapy for PE around the world,” said Dr. Matthai. “Despite advances in mechanical thrombectomy, anticoagulation alone remains the standard of care. This trial aims to generate definitive evidence to influence PE treatment guidelines worldwide."
PEERLESS II is the largest study of its kind and will include up to 1,200 randomized patients at up to 100 global centers. The study is running alongside the currently enrolling PEERLESS RCT, which is comparing FlowTriever to catheter-directed thrombolysis. Both trials aim to generate the high-quality clinical evidence needed to move the field forward and establish FlowTriever as the optimal therapy for intermediate-risk PE patients.
"PE is a leading cause of cardiovascular death and this first patient enrollment represents an important milestone in the evolution of care for this disease,” added Global Principal Investigator Dr. Jay Giri, Director of the Cardiovascular Catheterization Laboratories Associate Director and Associate Professor of Medicine at the Hospital of the University of Pennsylvania. “The rigorous trial design, including meaningful patient-centric endpoints and independent adjudication of all safety events, lays the groundwork for this landmark study to impact future PE treatment decisions. Thank you to the PEERLESS II Steering Committee and clinical staff for helping us get the first patient enrolled."
"Inari is actively enrolling three RCTs: PEERLESS, PEERLESS II and DEFIANCE, demonstrating our relentless commitment to guideline-changing research aimed at ultimately improving patient outcomes,” said Dr. Thomas Tu, Inari’s Chief Medical Officer. “With the commitment of our dedicated investigators, we look forward to expedited enrollment to get us closer to changing the standard of care."
For more information: www.inarimedical.com
November 12, 2025 
