The VAPOR 2 Study: Water Vapour Ablation Emerges as a Focal Therapy Option in Localized Prostate Cancer

KEY FINDINGS

• Interim analysis results for the first 110 patients in the VAPOR 2 (NCT05683691) trial were published in The Journal of Urology; the data evaluate the efficacy of water vapour therapy delivered with the Vanquish transurethral focal ablation system in localized, MRI-visible grade group 2 (GG2) prostate cancer.
• At targeted biopsy after 6 months, the treatment zone was completely benign in 75% of patients, and 91% had no residual GG2 disease.
• Visual clearance of the target zone on MRI was observed in 83% of patients; median PSA fell from 5.6 ng/mL to 2.3 ng/mL at 12 months (a 58% reduction, p < 0.001).
• No device-related serious adverse events or rectal injuries were reported; erectile dysfunction and urinary incontinence findings largely resolved over time.
• Francis Medical announced that the data will support its premarket approval application to the FDA to expand the Vanquish device's indication to localized prostate cancer.

Background and Study Design

Focal therapy approaches, which sit between radical treatment (surgery or radiotherapy) and active surveillance in low- and intermediate-risk localized prostate cancer, have attracted growing interest in recent years as a way to reduce treatment intensity and preserve quality of life in selected patients. While water vapour ablation is a technology long used in the treatment of BPH (the Rezum system), the VAPOR 2 trial adapts this principle to the focal ablation of localized prostate cancer for the first time.

VAPOR 2 is a prospective, multicentre, single-arm pivotal trial in men with intermediate-risk localized prostate cancer. A total of 235 patients are planned for enrolment at 26 clinical research sites across the United States, and the published data reflect a prespecified interim analysis of the first 110 patients who completed 12 months of follow-up.

Inclusion criteria include age 50 years or older, a single PI-RADS 3 or 4 lesion on multiparametric MRI, biopsy-confirmed GG2 disease, PSA ≤ 15 ng/mL and clinical stage ≤T2c. All patients underwent transurethral focal ablation with the Vanquish system in an outpatient setting. Median age was reported as 65 and median baseline PSA as 5.6 ng/mL.

Key Results

In terms of the safety profile, no device-related serious adverse events or rectal injuries were reported in the trial; perioperative complications were generally described as mild and self-limiting. Urinary and sexual function scores showed a transient decline in the early post-procedural period and then trended towards gradual improvement over 12 months.

"This publication strengthens the evidence base that thermal water vapour ablation is a promising focal ablative modality. The ability to target and ablate prostate tissue while minimising effects on surrounding structures may offer an important treatment option for appropriately selected patients."
- Samir S. Taneja, MD, Northwell Health, VAPOR 2 Co-Principal Investigator

Implications for Clinical Practice

The field of focal therapy continues to expand for the selected group of patients seeking alternatives that are less invasive and better preserve quality of life compared with radical surgery and radiotherapy. The initial results of VAPOR 2 suggest that water vapour ablation could position itself as an outpatient, minimally invasive option alongside existing focal modalities such as HIFU, cryoablation and focal laser ablation.

In robotic radical prostatectomy practice, such focal therapy data matter for patient counselling: the evidence base is strengthening for options that may be considered as alternatives to radical surgery in patients with low-to-intermediate risk, a single lesion and suitable anatomical features. However, the fact that a proportion of erectile dysfunction and incontinence cases persisted at month 12 shows that care is needed in patient selection and expectation management.

It should be emphasised that the Vanquish device is currently approved in the United States for transurethral thermal ablation of prostate tissue, and the FDA has not yet evaluated the device for the treatment of any disease, including prostate cancer, or for long-term oncological outcomes. The current data therefore fall within the scope of an investigational pivotal trial, and expanded FDA approval is awaited before routine clinical use.

Conclusion

The initial VAPOR 2 results published in the Journal of Urology demonstrate the potential of water vapour ablation as a focal therapy option that balances oncological control with preservation of quality of life in localized, intermediate-risk prostate cancer. As Francis Medical has announced, ongoing follow-up data will support the premarket approval application for an expanded device indication. With clearer patient selection criteria and long-term oncological outcomes, this development in focal therapy may find a wider place in uro-oncology practice.

References

1. Urology Times - Published VAPOR 2 data evaluate water vapor ablation for localized prostate cancer (2 July 2026)
2. The Journal of Urology - Water Vapor Therapy for the Management of Prostate Cancer: The VAPOR 2 Study Initial Results of Ablative Efficacy and Toxicity
3. Francis Medical - Francis Medical Announces Publication of VAPOR 2 Pivotal Trial Results in The Journal of Urology (30 June 2026)
4. PR Newswire - Francis Medical Announces Publication of VAPOR 2 Pivotal Trial Results