VIOLETTE Trial Shows Precise Planning in Prostate Cancer Microwave Ablation

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.

Investigators of the multicentric, phase 2 VIOLETTE trial (NCT04582656) evaluating the use of organ-based tracking fusion (OBT-Fusion) technology in focal ablation of the prostate by microwave needles has finalized enrollment and published interim results, Koelis, the developer, announced in a press release.¹

Further details will be presented at the 118th French Urology Congress in Paris.

The trial utilized the Koelis Trinity^® fusion imaging system, which employs OBT-Fusion technology to visualize and create a 3D map of the prostate while recording identified lesions. Investigators are evaluating the modality’s use through targeted microwave ablation.

“The Koelis technology not only helped to detect and characterize these tumors but also allowed precise planning for targeted treatment,” Barry-Delongchamps, professor of Urology at Cochin Hospital and the principal investigator of the VIOLETTE trial, said.¹ “As we look forward for the final oncologic results, we believe this new image-guided, needle-based technology is deemed to become an efficient and safe management option for selected patients.”

Per the released results, over 100% of tumor was covered by ablation, with DCE-MRI showing non-vascularized prostatic tissue in 97% of patients after 7 days. Additionally, 70% of the procedures were done 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 final patient was enrolled in September, bringing the total trial enrollment to 76 patients. Released data was centered on treatment data, safety, and biological and functional outcomes from the 37 patients who were first treated.

To be eligible for treatment, patients had to be between 45 and 76 years old with a life expectancy greater than 10 years, intermediate-risk prostate cancer defined by either T1c or T2a clinical state, a unique cancer focus of Gleason (3+4), or a PSA level of less than 20 ng/mL.² Patients also had to have no debilitating medical or psychiatric illness that preclude consent or the receiving of optimal treatment, among other requirements.

Exclusion criteria included past medical history of prostate surgery, radiotherapy, pelvic trauma, acute prostatitis, or cancer in the last 5 years; active taking of hormonal manipulation or androgen supplements; severe benign prostatic hyperplasia (BPH)-related urinary tract symptoms; or a tumor’s largest axis exceeding 12 mm on a prostate MRI, among other criteria.

The procedure consisted of 1 arm that received targeted ablation of the index tumor with microwaves, either through a transperineal or a transrectal approach.

The primary outcome measured was the proportion of patients with no evidence of cancer on targeted biopsy. Secondary outcomes include proportion of radical salvage treatment, time to radical salvage treatment, proportion of patients with any cancer in the untreated area, proportion of patients undergoing treatment for cancer in the untreated area, and urine flow.

Investigating trial centers are located in Bordeaux, Paris, and Nantes.

“Prostate care is undergoing a profound shift globally. At Koelis, we believe precision imaging can transform the lives of millions of [patients],” Antoine Leroy, PhD, founder and chief executive officer of Koelis said.¹ “As we work to become the preferred partner for urologists worldwide, we are proud that the VIOLETTE trial demonstrates Koelis’ leading role in enabling focal therapy for prostate cancer.”

References

1. KOELIS announces the first interim results of the VIOLETTE trial which evaluates the use of OBT-Fusion® technology in focal ablation of the prostate by microwave needles. News Release. Koelis. November 20, 2024. Accessed on November 21, 2024. https://tinyurl.com/47sh59su
2. Efficacy assessment of a novel 3D cartography-based targeted focal microwave therapy in men with localized intermediate-risk prostate cancer (VIOLETTE). ClinicalTrials.gov. Last updated August 6, 2021. Accessed November 21, 2024. https://tinyurl.com/2t5v534u