Peptide Receptor Radionuclide Therapy (PRRT) with Lu-177 PSMA-617 Vipivotide Tetraxetan (Pluvicto) on a recently diagnosed prostatic cancer as initial first line therapy.

Introduction: An otherwise healthy male presented with an elevated PSA of 6.8ng/ml, leading to a 14 sample Transrectal Ultrasound Scan (TRUS) guided biopsy. Pathology results showed a prostatic acinar carcinoma diagnosis with a Gleason score of 7 (4+3). Initial treatment was a laparoscopic robotic radical total prostatectomy, followed by Intensity Modulated Radiation Therapy (IMRT) to the pelvis for a total dose of 80Gy over 8-week duration. The PSA reached a nadir of 0.05ng/ml at 6 months post radiation, and subsequently rose to 0.39ng/ml after 2 months. A PET/CT was performed 2 months later following a 9.5 mCi IV injection of F-18 piflufolastat (Pylarify) at a PSA of 0.5ng/ml showing pelvic and retroperitoneal lymph node metastases.

Methods: At this point the standard care with hormonal therapy, chemotherapy and eventual orchiectomy was declined. It was decided to give Lu-177 Vipivotide tetraxetan at a PSA of 0.67ng/ml (Pluvicto, FDA approved on March 2022) with two doses of 5920 MBq 8 weeks apart. Blood work analysis and biodistribution images were obtained following each treatment.

Results: No side effects were reported after the first dose, the PSA dropped to 0.15ng/ml after 2 months. Mild side effects of abdominal discomfort, nausea and a deeper voice tone after the second dose, for less than 2 weeks were noted, the PSA dropped even further to 0.07ng/ml 3 months later. Prostatic cancer continues to represent a major health problem with no effective treatment for advanced metastatic disease. Considering that eventual resistance/failure to the standard care therapies will occur, a more successful treatment at an early stage would be preferable with the newest PRRT radioligand. The response to Pluvicto was quite remarkable. Such an impressive and prominent drop in the PSA levels were anticipated and with minimal side effects. All blood work analysis continues to be normal and will continue to be assessed. The usual daily normal routine activities/exercises remained uninterrupted. Monitoring with PSA levels will continue as a follow-up to evaluate this treatment’s efficacy. An extensive literature search did not yield any single similar report.

Conclusions: Excellent response to 2 Pluvicto infusions showing no signs of metastatic disease, lower PSA levels, and with relatively negligible minor side effects were noticed. Treatment alternatives for patients such as this case should be evaluated based on risk consideration toward a goal of greatest efficacy and least harm over time due to unnecessary/unpredicted side effects. The future of this theranostic approach is in using this very effective therapy in earlier disease state that perhaps modifies the most common/serious malignant disease in men into a chronic manageable disorder.