Introduction:

The VAPOR 2 Study is a novel, 5-year, multicenter trial using a transurethral thermal water vapor device (Vanquish) to manage localized intermediate-risk prostate cancer. This report represents the initial 110 treated patients with a minimum of 12-month follow-up.

Methods:

The Vanquish System is a transurethral, ultrasound guided thermal water vapor device used to convectively ablate targeted prostate tissue in any location or anatomic prostate zone.  Following IRB approval, 27 sites treated 235 patients from July 2023 to February 2025.  Treatment strategy was ablating the MRI target and a minimum 1cm intraprostatic margin. Fusion biopsy targeting the infield area and a sector biopsy occurred 6-months post treatment. 

Patients with a single PI-RADS 3 or 4 target and GG2, confirmed by fusion biopsy, PSA <15ng/ml, and no MRI evidence of ECE were included. All MRIs were centrally interpreted by radiologists using AI assistance (Quantib) following the PIRADSv2. There were no exclusions based on tumor location including the distal apex or proximity to the capsule or urethra. 

Safety and adverse reporting were classified using the CTCAE system. 

Results:

For 110pts, the index lesion was located at the apex in 34pts (31%), mid in 67 (61%), and base in 21 (19%). In 12pts, the target was in >1 sector.  Targets were in the PZ for 87 patients (79%). 34 targets (31%) were located anteriorly.

108 patients underwent a 6-month biopsy. 91% (98/108) of infield biopsies were negative for ≥GG2 disease following a single procedure. 

PSA reduced by 52% from 6.3ng/ml [1.5, 14.9] (n=110) to 3.0ng/ml [0.3, 15.6] (n=108) at 1-year. 

101pts (92%) were catheterized once (median 5 days, range 2-9). There were no ≥Grade 3 urinary incontinence events or rectal injuries reported. 

The IIEF-5 mean change at each time point was less than the minimal clinically important difference (MCID) of 4 points. 

For 106 pts at 1-year, the Decision Regret Scale (0-100) was 10.3 indicating “no to mild regret” (score - 0 to 25).

No device related SAE’s occurred.

Conclusion:

This initial report shows a 91% clearance of targeted MRI visible ≥GG2 disease following a single treatment and the ability to treat anywhere in the prostate. Consistent with the convective mechanism of ablation, excellent short term oncologic control and 1-year safety profile with no device related SAE’s, low morbidity and low patient regret was achieved. This study is ongoing with a 3-year analysis planned to support management of prostate cancer.

Funding: Francis Medical Inc