Outcome and Renal Safety of PSMA-Targeted Radioligand Therapy in mCRPC Patients With Preexisting Impaired Renal Function

Abstract

Purpose: This study aims to evaluate the outcome and renal safety of prostate-specific membrane antigen (PSMA)–radioligand therapy (RLT) in patients with metastatic castration-resistant prostate carcinoma (mCRPC) and preexisting renal impairment. Methods: Ninety-four patients with preexisting renal impairment were included in this retrospective analysis. Inclusion criterion was a glomerular filtration rate (GFR) of ≤60 mL/min (equivalent to Common Terminology Criteria of Adverse Events [CTCAE] ≥2). Patients underwent either [177Lu]Lu-PSMA-617 RLT exclusively (n = 63) or additionally in augmented manner with [225Ac]Ac-PSMA-617 (n = 31). The median number of administered cycles was 4 (range, 1–16 cycles) with a mean cumulative activity of 29.9 ± 16.3 GBq (range, 6.9–87.2 GBq) [177Lu]Lu-PSMA-617. Main blood parameters of interest were creatinine, cystatin C, and the respective GFR values. Changes in GFR were categorized according to CTCAE v5.0. Results: In the entire cohort, mean best PSA response was −56.73% ± 45.71%, with 63 of 94 patients (67%) experiencing partial remission. The median progression-free survival and overall survival were 6.7 and 14.1 months, respectively. Under PSMA-RLT, 5 of 94 patients (5.3%) improved to CTCAE grade 0, and 23 of 94 (24.5%) improved to CTCAE grade 1. Three of 94 patients (3.2%) improved from CTCAE grade 3 to grade 2, and only 5 of 94 (5.3%) decreased. The majority (58/94 [61.7%]) of patients stayed stable in terms of CTCAE grading. Conclusions: PSMA-RLT is an effective and safe treatment in mCRPC patients with preexisting impaired renal function (CTCAE ≥2). In daily clinical practice, patients should not be categorically excluded from enrolment to PSMA-RLT due to renal impairment.