The SURE Procedure with the CVAC System delivers 97% stone clearance independent of baseline stone volume; first and only prospective kidney stone clinical study to use continuous volumetric measurements to measure success as advocated by global thought leaders in endourology

Calyxo, Inc., a medical device company developing paradigm-shifting solutions for patients with kidney stones, today announced the publication of the complete 30-day outcomes from the ASPIRE (ASPiration to Improve Renal Calculi Removal Effectiveness) clinical trial in the Journal of Endourology. The positive study results demonstrate that steerable ureteroscopic renal evacuation (SURE) using Calyxo’s CVAC Aspiration System delivered significantly higher clearance of kidney stones and significantly lower residual stone volume (RSV) compared with traditional ureteroscopy (URS)¹. Data from the ASPIRE study were initially reported at the American Urological Association (AUA) Annual Meeting in May 2024².

“The 30-day results from the ASPIRE study demonstrate that CVAC is highly effective across a broad range of stone sizes,” said Brian R. Matlaga, MD, MPH, Professor of Urology and Director, The Stephens Center for Stone Disease, at Johns Hopkins University School of Medicine and lead author on the publication. “This is especially noteworthy in that the CVAC System is the first aspiration technology to demonstrate high effectiveness that does not wane with larger baseline stone volumes. This is a distinct contrast to what we observe in conventional URS^3-6 or other suction-based technologies such as flexible and navigable sheaths (FANS) wherein effectiveness declines as baseline stone volume increases.^7,8”

A key limitation of kidney stone studies has been the use of stone free rate (SFR)-- a binary metric reporting whether residual fragments (RF) are present or not—as the standard measure of success. SFR is fraught with inconsistencies in how it is reported, using varying thresholds for stone-free (zero RF, no RF > 2mm, no RF > 4mm), imaging methods (X-ray, ultrasound, non-contrast computed tomography NCCT), slice thicknesses if NCCT is used, and timing after treatment (30 days, 6 weeks, etc.), making comparison of outcomes impractical. At the same time, multiple studies have shown that the presence of residual fragments (RF), irrespective of size of RF, are associated with complications such as pain, stone regrowth, and emergency department visits^9-15. Global leaders in endourology now advocate using continuous variables such as stone clearance (percent stone volume removed) and residual stone volume (RSV) to measure success as they provide a more objective, refined and clinically meaningful measure of how much stone is removed and how much absolute volume of stone is left¹⁶.

ASPIRE, a multi-center, prospective, randomized, non-inferiority, controlled trial is not only the first to utilize stone clearance and residual stone volume in a clinical trial, it also sets a new level of rigor by using 1.25mm NCCT slices (instead of the typical 3-5mm slices) that increases the accuracy of stone volume measurement and the detection of RF. This study represents the highest level of evidence possible (Level 1) due to its strict study design, which is uncommon in kidney stone research.

101 patients across 11 U.S. institutions were treated with either SURE using the CVAC System or with URS between June 2021 and February 2023 and analyzed for efficacy. All endpoints were met with key findings as follows:

• SURE with the CVAC System achieved significantly superior stone clearance vs, URS at 30 days, with a mean reduction in stone volume of 97% for SURE vs. 93% for URS (p=0.036)
• RSV was significantly lower with SURE vs. URS at 30 days with mean RSV of 14.3 mm³ for SURE and 70.2 mm³ for URS (p=0.012).
• Regression analysis showed that SURE maintained high stone clearance and low RSV regardless of baseline stone volume whereas with URS, efficacy worsened with increasing baseline stone volume.

“The ASPIRE results published today add to a growing body of evidence showing that SURE with the CVAC System has significant efficacy advantages compared with URS and proves that more complete stone clearance is possible,” said Joe Catanese, PhD, President & Chief Executive Officer of Calyxo. “We believe the newly published data will advance kidney stone research and foster the growing enthusiasm for the CVAC System within the clinical community, as we continue to make SURE more broadly available to patients who need an effective and safe treatment for kidney stones.”

Initial one-year data from the ASPIRE study was presented in August 2024 at the 41st World Congress of Endourology and Uro-Technology (WCET) that showed healthcare consumption one year post-procedure was lower in patients who had undergone SURE with the CVAC System compared with URS, including reductions in emergency department visits, hospitalization, and retreatment¹⁷.

About Kidney Stones

Approximately 10% of people in the U.S. will have a kidney stone at some point in their lives, according to the American Urological Association. Kidney stone disease is a painful condition that brings with it significant healthcare costs (current Urology Reports estimates $4.1 billion in annual direct treatment costs by 2030).

About the CVAC System

The new CVAC System was recently FDA-cleared and enables a minimally invasive approach for kidney stone clearance. It is an all-in-one solution that is designed to efficiently and effectively remove kidney stones. It uses irrigation and vacuum aspiration to continuously clear stone fragments during and after laser lithotripsy, enabling physicians to achieve a stone-free outcome.

About Calyxo, Inc.

Calyxo, Inc. is an innovation-driven medical device company focused on improving care for patients with kidney stones by delivering paradigm-shifting solutions that enable urologists to safely, effectively and efficiently achieve unrivaled clinical outcomes. Learn more at calyxoinc.com.

“CVAC” and “Calyxo” are registered trademarks of Calyxo, Inc.

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