Violette Clinical Trial

Study Presentation

Today, although several therapeutic alternatives exist, the management of intermediate-risk prostate cancer remains a subject of debate. Indeed, due to their important impact on quality of life, radical treatments, such as surgery or external radiotherapy, are not suitable for these patients. Radical prostatectomy is correlated to urinary (incontinence) and sexual issues, raising the question of the benefit-risk ratio for patients with less aggressive tumors.

An innovative alternative is under investigation: targeting the most aggressive tumor, knows as the “index tumor”, to reduce the risk of progression and avoid a radical treatment. To perform such treatment, it is necessary to localize the tumor and to focus the therapeutic agent on the area which needs to be treated precisely.

Based on this assumption, KOELIS aims to combine tumor localization by MRI and targeted biopsies with image fusion to assess the efficacy of a targeted focal microwave treatment. As such, 76 patients with a localized intermediate-risk prostate cancer have been enrolled and benefited from a TMA treatment in a European and multicenter trial, called VIOLETTE. Those patients are now followed for 12 months after the intervention. The first intermediate results have been published and the final results will be provided at the completion of this study.

« Koelis is clearly committed to clinical research, with a strategy based on ethical and scientific choices. The multicenter Violette study (NCT04582656) we are carrying out is evaluating the efficacy of focal ablation of prostate cancer using a microwave needle guided by 3D image fusion. The last patient was treated on September 05, 2024 at the Clinique Saint-Augustin in Bordeaux (76 patients treated in total), we look forward to the end of patient follow-up for a final results analysis » emphasizes Claire Jossan, Head of Clinical Research at KOELIS.

The different steps

Feasibility and safety (Fostine trial): OBT-fusion Targeted Microwave Abalation (TMA) was feasible, precise, and safe in patients with low to intermediate risk localized prostate cancer.

Intermediate results (first results of Violette): These preliminary results suggest that TMA using OBT fusion is precise and safe in patients with intermediate risk localised prostate cancer.

Final results (to be published): the final results will be published after the 1 year follow up of the last patient.

Intermediate results

Complete tumor coverage was achieved with ablation, with DCE-MRI showing non-vascularized prostatic tissue in 97% of patients after 7 days. Additionally, 70% of procedures were performed transperineally, and the median pain level was 0/10 on a visual analog scale 2 hours after the procedure. All treated patients recovered spontaneous micturition and were discharged on the same day. Also, there was an observed decrease in prostate-specific antigen (PSA) and PSA density that was stable after a 1-month follow-up.

Regarding safety and adverse events (AEs), there was no significant impact on urinary or sexual function reported, and 58 AEs were found in 22 patients, 5 of which were severe and resolved at the time of analysis.

The primary outcome was the proportion of patients with no evidence of cancer on targeted biopsy. Secondary outcomes included rates of radical salvage treatment, detection of cancer in untreated areas, treatment rates for cancer in untreated areas, and changes in urine flow.

Bilbiography

Barry Delongchamps N et al – Feasibility and safety of targeted focal microwave ablation of the index tumor in patients with low to intermediate risk prostate cancer: Results of the FOSTINE trial. PLoS One. 2021 Jul > Link

Oderda M et al. Safety and Feasibility of Transperineal Targeted Microwave Ablation for Low- to Intermediate-risk Prostate Cancer. Eur Urol Open Sci. 2022 Oct 22. > Link

Chiu PK et al. Transperineal Targeted Microwave Ablation (TMA) of localized prostate cancer guided by MRI-Ultrasound fusion and organ-based tracking: a pilot study. Prostate Cancer Prostatic Dis. 2023 Dec. > Link

Chiu PK et al. Targeted Microwave Ablation (TMA) for prostate cancer under MRI-Ultrasound fusion and organ-based tracking: final results of the first phase 2 trial on efficacy. EU Oncology – 2024 Nov > Link

Oderda M., et al. Transperineal 3D fusion imaging-guided targeted microwaves ablation for low to intermediate-risk prostate cancer: results of a phase I-II study – MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES Nov 2024 > Link

Peltier A et al. Targeted microwave ablation for prostate cancer (FOSTINE1b): a prospective ‘ablate-and-resect’ study. BJU Int. 2024 May 14. > Link

Barry Delongchamps N., et al. Targeted microwave ablation of localised prostate cancer: Initial results of VIOLETTE trial. BJU Compass 08/2024 > Link