Data from the prospective ASPIRE trial, published in the Journal of Endourology, indicates that steerable ureteroscopic renal evacuation (SURE) using the CVAC system achieves a stone-free rate (SFR) noninferior to that of standard ureteroscopy (URS) for nephrolithiasis. The study highlights the potential of the CVAC system as an effective alternative for kidney stone treatment.
The ASPIRE trial (NCT06615713) enrolled 123 adult patients across 11 clinical trial sites in the US, all candidates for laser lithotripsy with at least one renal stone ≥ 7 mm and a stone burden of 7-20 mm. Participants were randomized 1:1 to undergo either SURE or URS. Efficacy analysis included 46 patients undergoing SURE and 55 undergoing URS.
Noninferior Stone-Free Rate
The ASPIRE study met its primary endpoint, demonstrating noninferiority of the SURE procedure versus URS in SFR based on zero residual fragments (RFs) on non-contrast CT at 30-day follow-up. The SFR with the SURE procedure was 48%, compared to 49% with URS (-1.3%; 90% confidence interval, -18%-15%; P = .027).
Superior Stone Clearance and Reduced Residual Stone Volume
The SURE procedure also resulted in significantly better outcomes on the study’s secondary endpoints 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 ± 30.9 mm3 in the SURE arm versus 70.2 mm3 ± 144.9 mm3 in the URS arm (P = .012).
Stone Volume Impact
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 in the SURE arm. However, a negative correlation was observed 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).
Safety Profile
Safety was comparable between both arms. According to Brian R. Matlaga, MD, MPH, professor of urology and director of The Stephens Center for Stone Disease at Johns Hopkins University School of Medicine, the 30-day results from the ASPIRE study demonstrate that CVAC is highly effective across a broad range of stone sizes.
Company Statements
Joe Catanese, PhD, president & CEO of Calyxo, stated that the ASPIRE results add to the 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.
