Published ASPIRE data show noninferior stone-free rate with SURE vs URS

Data from the prospective ASPIRE trial (NCT06615713) have been published in the Journal of Endourology, showing that the stone-free rate (SFR) achieved through steerable ureteroscopic renal evacuation (SURE) was noninferior to that of standard ureteroscopy (URS) for nephrolithiasis.¹

Brian R. Matlaga, MD, MPH

The SURE procedure was performed with the CVAC device, which was granted FDA clearance in March 2024 for its new redesign.²

“The 30-day results from the ASPIRE study demonstrate that CVAC is highly effective across a broad range of stone sizes,” said lead author Brian R. Matlaga, MD, MPH, professor of urology and director of The Stephens Center for Stone Disease at Johns Hopkins University School of Medicine, in a news release on the findings.³ “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 or other suction-based technologies such as flexible and navigable sheaths (FANS) wherein effectiveness declines as baseline stone volume increases.”

Overall, the ASPIRE study met its primary end point by showing noninferiority of the SURE procedure vs URS in SFR based on zero residual fragments (RFs) on non-contrast CT at 30-day follow-up. Specifically, the SFR with the SURE procedure was 48%, vs 49% with URS (-1.3%; 90% confidence interval, -18%-15%; P = .027).

The SURE procedure also resulted in significantly better outcomes on the study’s secondary end points of stone clearance (percent reduction in stone volume) and residual stone volume (RSV). In the SURE arm, the reduction in stone volume was 96.9% ± 5.6% compared with 92.9% ± 11.6% in the URS arm (P = .036). Additionally, RSV was 14.3 mm³ ± 3 0.9 mm³ in the SURE arm vs 70.2 mm³ ± 144.9 mm³ in the URS arm (P = .012).

In the SURE arm, stone clearance (Pearson’s correlation coefficient = 0.02; P = .89) and RSV (correlation coefficient = 0.24; P = .11) were not found to be dependent on baseline stone volume. However, a negative correlation was seen between stone clearance and baseline stone volume in the URS arm (correlation coefficient = −0.30; P = .025), indicating that efficacy worsened as stone volume increased. Additionally, a positive correlation was noted between RSV and baseline stone volume in the URS arm (correlation coefficient = 0.68; P < .001).

There was no statistically significant difference between the 2 arms in regard to the secondary end point of SFR based on no RF greater than 2 mm or no RF greater than 4 mm.

Safety was also found to be comparable between both arms.

“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 & CEO of Calyxo, in the news release.³ “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.”

In total, the ASPIRE trial enrolled 123 adult patients across 11 clinical trial sites in the US. All participants were candidates for laser lithotripsy and had at least 1 renal stone that was 7 mm or greater and a stone burden of 7-20 mm.

Patients enrolled in the study were randomly assigned 1:1 to undergo either SURE or URS. A total of 101 patients were eligible for inclusion in the efficacy analysis, of whom 46 underwent SURE and 55 underwent URS. All baseline characteristics were comparable between both arms except for stone volume, which was greater in the URS cohort. The total baseline stone volume was 485.0 mm³ ± 432.5 mm³ in the SURE arm vs 713.3 mm³ ± 558.5 mm³ inthe URS arm.

Overall, the authors concluded, “These results suggest that SURE has a role in the treatment of nephrolithiasis; longer follow-up will better inform the clinical and health economic effect of improved stone clearance, including the need for retreatment.”

References

1. Matlaga BR, Mueller TJ, Johnson B, et al. A prospective, randomized, noninferiority study to evaluate the safety and effectiveness of steerable ureteroscopic renal evacuation compared with standard ureteroscopy: 30-day results of the ASPIRE study. J Endourol. 2024. doi:10.1089/end.2024.0602

2. Calyxo announces FDA clearance for new, redesigned CVAC System. News release. Calyxo, Inc. March 26, 2024. Accessed December 23, 2024. https://calyxoinc.com/calyxo-news/calyxo-fda-approved-cvac-system-kidney-stones/

3. ASPIRE level 1 outcomes published demonstrating superior stone clearance with the SURE procedure using the CVAC System vs. standard ureteroscopy. News release. Calyxo, Inc. Published online and accessed December 23, 2024. https://calyxoinc.com/calyxo-news/aspire-1-year-results-cvac-system-urolithiasis-kidney-stone-treatment-wcet-2024/