Jupiter Endovascular Reports Positive SPIRARE II Pivotal Trial Results at EuroPCR 2026
Jupiter Endovascular, Inc. announced positive topline results from its pivotal SPIRARE II clinical trial evaluating the company’s Vertex™ Pulmonary Embolectomy System in patients with acute intermediate-risk pulmonary embolism (PE). According to the company, the study successfully achieved both of its primary endpoints, demonstrating significant improvement in right-heart function along with a favorable safety profile.
The late-breaking clinical data were presented at EuroPCR 2026 in Paris by Catalin Toma, who also served as Global Co-Principal Investigator of the SPIRARE II study. The results represent a potentially important advancement in the treatment of pulmonary embolism, particularly in patients experiencing significant hemodynamic compromise and right-heart strain.
Pulmonary embolism is a serious cardiovascular condition caused by blood clots obstructing pulmonary arteries in the lungs. In severe cases, the blockage can place substantial pressure on the right side of the heart, impair circulation, and potentially lead to life-threatening complications. While thrombectomy procedures aim to remove clots mechanically, clinicians increasingly recognize that restoring hemodynamic stability and reducing cardiac strain are equally important therapeutic goals.
According to Sameh Sayfo, who also served as Global Co-Principal Investigator of SPIRARE II, pulmonary embolism should be viewed primarily as a cardiovascular disease centered on restoring physiologic stability rather than simply removing thrombus burden.
Sayfo explained that one of the longstanding limitations in pulmonary embolism intervention has been the difficulty of achieving both safe navigation through the right heart and sufficient procedural stability during thrombectomy. These technical challenges can affect consistency in restoring hemodynamics and improving patient recovery. He noted that the SPIRARE II study offered an opportunity to evaluate a system designed not only for clot extraction, but also for improved procedural precision and physiologic impact.
At the center of the study is the Vertex Pulmonary Embolectomy System, which utilizes Jupiter Endovascular’s proprietary Transforming Fixation, or TFX, platform technology. The catheter-based system is engineered to navigate flexibly through the right side of the heart before stabilizing within the pulmonary arteries during intervention. According to the company, this dual functionality is intended to address several procedural challenges associated with pulmonary embolism thrombectomy, including maintaining stable vessel access while minimizing cardiac strain during clot removal.
The SPIRARE II trial, identified as NCT06576427, was designed as a prospective, single-arm, multicenter pivotal study enrolling 123 patients across 19 clinical sites in Europe and the United States. The study evaluated the safety, right-heart functional recovery, and overall clinical outcomes associated with use of the Vertex system in patients diagnosed with acute intermediate-risk pulmonary embolism.
Jupiter Endovascular reported that the study successfully met both primary endpoints. The first primary endpoint evaluated improvement in right-heart function as measured by reduction in the right ventricular to left ventricular ratio, commonly referred to as the RV/LV ratio. Elevated RV/LV ratios are associated with right-heart strain and poor outcomes in pulmonary embolism patients. Investigators observed a mean reduction of 0.39 in RV/LV ratio at 48 hours following treatment, with a 95% confidence interval ranging from 0.33 to 0.45.
The second primary endpoint focused on safety, specifically the rate of major adverse events. According to the study data, the trial demonstrated a major adverse event rate of 2.4%, representing three events among 123 patients. The results achieved strong statistical significance with a reported p-value of less than 0.0001.
Beyond the primary endpoints, investigators also reported substantial improvements in invasive hemodynamic measurements following thrombectomy with the Vertex system. The company stated that the TFX-enabled procedure achieved meaningful reductions in cardiac afterload and supported right-heart recovery beyond clot extraction alone.
Among the reported findings, investigators observed a 29% reduction in mean pulmonary artery pressure and an equivalent 29% reduction in systolic pulmonary artery pressure. In addition, total pulmonary vascular resistance declined by 26% following intervention. These measurements suggest significant improvement in pulmonary circulation dynamics and reduced stress on the right ventricle after treatment.
The trial also demonstrated strong procedural performance characteristics. Investigators reported a 100% technical success rate, with no need for adjunctive thrombolytic therapy during procedures. The absence of thrombolytic drug use may be clinically meaningful because thrombolytics can increase bleeding risk in some patients.
Additional procedural data indicated that the Vertex system may simplify certain aspects of pulmonary embolism intervention. According to the study, 83% of procedures did not require re-crossing of the pulmonic valve, while 39% of cases avoided the use of super-stiff guidewires commonly employed in complex catheter procedures. Investigators also reported an average procedure time of approximately 40.2 minutes, with a standard deviation of 16.4 minutes, suggesting a relatively efficient intervention process.
Toma emphasized that the SPIRARE II results were particularly notable given the severity of the enrolled patient population. According to the study data, 54% of participants presented with normotensive shock, while 93% were classified within the higher-risk C3 or D2 categories under the 2026 American College of Cardiology and American Heart Association pulmonary embolism guidelines.
Toma stated that TFX-enabled thrombectomy produced consistent and reproducible physiologic recovery across multiple patient classifications. He suggested that the stable and controlled vessel access enabled by the technology may have contributed significantly to the observed outcomes. He added that future post-hoc analyses could help investigators better understand the relationship between procedural access and the depth of physiologic improvement observed during the study.
According to Toma, the findings may ultimately influence how clinicians approach pulmonary embolism intervention in the future, particularly in patients with elevated hemodynamic risk and right-heart dysfunction.
Carl J. St. Bernard said the SPIRARE II study was intentionally designed not only to support future regulatory submissions, but also to generate a comprehensive dataset including invasive hemodynamic measurements and detailed patient-level clinical information across a relatively severe patient population.
St. Bernard noted that the findings contribute to a broader understanding of pulmonary embolism as a multifaceted cardiovascular disease characterized by right-heart dysfunction and hemodynamic instability rather than clot burden alone. He thanked the patients, investigators, and clinical teams involved in the trial for helping advance the field toward more sophisticated approaches to pulmonary embolism treatment.
Looking ahead, Jupiter Endovascular indicated that it plans to move toward commercialization of the Vertex system while continuing to explore additional applications for its TFX platform technology. The company believes the technology could potentially address unmet needs in other complex cardiovascular procedures where stable vessel access and controlled intervention remain significant technical challenges.
The SPIRARE II results arrive amid growing interest in catheter-based pulmonary embolism therapies and increasing recognition of the importance of right-heart recovery in determining long-term patient outcomes. As cardiovascular specialists continue to refine treatment strategies for acute pulmonary embolism, technologies capable of combining effective clot removal with improved procedural control and hemodynamic restoration may play an increasingly important role in future standards of care.
About the Vertex™ Pulmonary Embolectomy System and TFX Technology
The Vertex Pulmonary Embolectomy System leverages Jupiter Endovascular’s proprietary Transforming Fixation (TFX) platform technology to navigate flexibly through the right heart and transform into a stabilized state in the pulmonary arteries for precise, controlled intervention. TFX’s unique capability to decouple flexible navigation from stable support addresses long-standing challenges in PE thrombectomy related to cardiac strain, guidewire reliance, and reliable vessel access — enabling the system to achieve afterload relief and hemodynamic recovery alongside clot removal.
About Jupiter Endovascular
Jupiter Endovascular, Inc. is a Menlo Park, California-based medical technology company developing a new class of endovascular interventions using its proprietary Transforming Fixation (TFX) technology. The company’s lead program, the Vertex Pulmonary Embolectomy System, is designed to provide physicians with on-demand stability and control during transcatheter intervention in the pulmonary vasculature. For more information, visit jupiterendo.com.
Forward-looking statements contained in this press release are based on estimates and assumptions of Jupiter Endovascular management and are believed to be reasonable, though they are inherently uncertain and difficult to predict. Our forward-looking statements speak only as of the date on which they are made. We do not undertake any obligation to update any forward-looking statement to reflect events or circumstances after the date. Forward-looking statements involve risks and uncertainties that could cause results to differ materially from those expressed or implied based on a number of factors, including but not limited to, unexpected clinical trial timing and outcomes, results of expanded clinical experience and unanticipated impacts of regulatory decisions.
Caution: The Vertex™ Pulmonary Embolectomy System is investigational and not approved for commercial use in the United States or Europe.
