Lutetium-177 prostate-specific membrane antigen radioligands (177Lu-PSMA) are new therapeutic agents for the treatment of metastatic castration-resistant prostate cancer (mCRPC). We evaluated the prognostic value of circulating tumour DNA (ctDNA) profiling in patients with mCRPC starting treatment with 177Lu-PSMA I&T. Between January 2020 and October 2022, patients with late-stage mCRPC (n = 57) were enrolled in a single-centre observational cohort study. Genomic alterations in the AR gene, PI3K signalling pathway, TP53, and TMPRSS2-ERG were associated with progression-free survival (PFS) on Kaplan-Meier and multivariable Cox regression analyses. Median PFS of 3.84 mo (95% confidence interval [CI] 3.3-5.4) was observed, and 21/56 (37.5%) evaluable patients experienced a prostate-specific antigen response of ≥50% during treatment. Among 46 patients who provided a blood sample for profiling before 177Lu-PSMA treatment. ctDNA was detected in 39 (84.8%); higher ctDNA was correlated with shorter PFS. Genomic structural rearrangements in the AR gene (hazard ratio [HR] 9.74, 95% confidence interval [CI] 2.4-39.5; p = 0.001) and alterations in the PI3K signalling pathway (HR 3.58, 95% CI 1.41-9.08; p = 0.007) were independently associated with poor 177Lu-PSMA prognosis on multivariable Cox regression. Prospective evaluation of these associations in biomarker-driven trials is warranted.
We examined cell-free DNA in blood samples from patients with advanced metastatic prostate cancer who started treatment with lutetium-177-PSMA, a new radioligand therapy. We found that patients with genetic alterations in the androgen receptor gene or PI3K pathway genes did not experience a lasting benefit from lutetium-177-PSMA.
European urology open science. 2023 May 30*** epublish ***
Jan Vanwelkenhuyzen, Eva Van Bos, Siska Van Bruwaene, Karl Lesage, Alex Maes, Sezgin Üstmert, Filip Lavent, Laurence Beels, Henrik Grönberg, Piet Ost, Johan Lindberg, Bram De Laere
Department of Human Structure and Repair, Ghent University, Ghent, Belgium., Department of Urology, AZ Groeninge, Kortrijk, Belgium., Department of Nuclear Medicine, AZ Groeninge, Kortrijk, Belgium., Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.