(UroToday.com) The 2024 American Urological Association (AUA) Annual Meeting held in San Antonio, TX was host to an advanced prostate cancer moderated poster session. Dr. Ahmed Mahmoud presented the results of a study evaluating response to 177Lu-PSMA-617 by site-specific disease in patients with metastatic castrate-resistant prostate cancer.
In 2022, the United States Food and Drug Administration (FDA) approved 177Lu-PSMAfor the treatment of PSMA-positive mCRPC patients who have been treated with an androgen receptor pathway inhibitor and taxane-based chemotherapy.1 Since then, multiple studies have evaluated responses to 177Lu-PSMA; however, few studies have described response based on site of disease progression. In this study, the investigators sought to evaluate the response to 177Lu-PSMA by the site of metastatic spread.
They conducted a retrospective analysis of 273 patients who received treatment with 177Lu-PSMA at The Mayo Clinic between April 2022 and September 2023. Of these 273 patients, they identified 76 (28%) who presented with either bone-only or lymph node-only disease. Patient-level clinicopathological variables, follow-up imaging, and clinical outcomes data were abstracted for all patients. Univariable comparisons were performed using the Chi-square and Kruskal-Wallis tests for categorical and continuous variables, respectively.
These 76 patients were classified into one of two groups according to the site of metastatic disease: pure bone disease (n=52; 68%) and pure nodal disease (n=24; 32%). Patients in the bone group had higher Gleason Scores (p=0.019) and PSA levels (p=0.16) prior to the start of 177Lu-PSMA therapy.
At a median follow-up of 10.2 (IQR: 8.6–11.5) months from the first 177Lu-PSMA cycle, the post-treatment PSA kinetics did not differ significantly between the two groups. However, patients with nodal disease demonstrated a durable response in terms of decreased post-treatment SUVmax of metastatic lesions (p=0.0299) and a lower rate of radiographic disease progression (p=0.0011), compared with the bone group.
Dr. Mahmoud concluded that patients with lymph node-only disease treated with 177Lu-PSMA had a durable response compared to those with bone-only disease. Further prospective studies are needed to validate the findings from this study.
Presented by: Ahmed Mahmoud, MD, Research Fellow, Department of Urology, Mayo Clinic, Rochester, MN
Written by: Rashid Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2024 American Urological Association (AUA) Annual Meeting, San Antonio, TX, Fri, May 3 – Mon, May 6, 2024.
References:
- FDA D.I.S.C.O.: Burst Edition: FDA approval of Pluvicto (lutetium Lu 177 vipivotide tetraxetan) for the treatment of adult patients with prostate-specific membrane antigen-positive metastatic castration-resistant prostate cancer who have been treated with androgen receptor pathway inhibition and taxane-based chemotherapy. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-disco-burst-edition-fda-approval-pluvicto-lutetium-lu-177-vipivotide-tetraxetan-treatment-adult. Accessed on May 6, 2024.