(UroToday.com) The 2022 ESMO annual meeting featured a prostate cancer session, including a presentation by Dr. Robert Tauber discussing treatment efficacy and safety of 177Lu-PSMA radioligand therapy in octogenarians with mCRPC. Based on several studies, including the phase 3 VISION trial [1], 177Lu-PSMA radioligand therapy is an option for treatment of mCRPC. Additionally, it is increasingly used in old or comorbid patients. The purpose of this analysis presented at ESMO 2022 was to evaluate the safety and efficacy in patients ≥80 years of age.
There were 80 mCRPC patients who underwent 177-lutetium–labeled PSMA-I&T radioligand therapy at the age of 80 or older (median age 82, IQR:80-91) between March 2016 and September 2021 selected from Dr. Tauber’s institutional database. Patients were previously treated with androgen receptor-directed therapy and taxane-based chemotherapy or were chemotherapy-ineligible. All patients showed high PSMA-ligand uptake at PSMA-PET. Treatment was performed with a total of 324 cycles (median 4 cycles, range: 1–12) and a median activity of 23.8 GBq (IQR: 14.8-42.2) on a 4 to 6 weeks interval base. Toxicity data were acquired 6 months after the last treatment. Additionally, best PSA-response, progression-free survival (PFS) and overall survival (OS) were obtained.
The median number of previous mCRPC treatment regimens was 2 (range 1-6), 62.5% of patients were chemotherapy-naïve before Lu-177-PSMA therapy, 17.5% of patients had visceral metastases. A PSA decline of 90% was achieved in 27.5% and a 50%-PSA decline in 46.3% of patients:
Chemotherapy-naïve patients showed higher PSA response rates compared to chemotherapy-pretreated patients (55.1% vs. 44.0% 50%-PSA-decline). As follows is a comparison of PSA progression free survival, clinical progression free survival, and overall survival in chemotherapy naïve vs chemotherapy pretreated patients:
Overall, median PFS and OS were 8.7 and 16.1 months, and median PFS and OS of chemotherapy-naïve patients were significantly longer compared to chemotherapy-pretreated patients (10.5 months vs. 6.5 months and 20.7 vs. 11.8 months, respectively, both p<0.01). Treatment related grade 3 toxicities were anemia in 5%, thrombocytopenia in 4%, and chronic renal impairment in 8% patients, no non-hematologic grade 3 and no grade 4 toxicities were observed. The most frequent clinical side effects were grade 1-2 xerostomia, fatigue, and lack of appetite.
Dr. Tauber concluded his presentation discussing treatment efficacy and safety of 177Lu-PSMA radioligand therapy in octogenarians with mCRPC with the following take-home messages:
- Response rates and toxicity of 177Lu-PSMA radioligand therapy in old mCRPC patients are comparable to published data
- Chemotherapy-naïve patients showed a better and longer response to therapy than chemotherapy-pretreated patients
- PSMA radioligand therapy seems to be a meaningful treatment option for older patients
Presented by: Robert L. Tauber, Urology, Klinikum Rechts der Isar - Technische Universitaet Muenchen, Munich, Germany
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2022 European Society of Medical Oncology (ESMO) Annual Hybrid Meeting, Paris, FR, Fri, Sept 9 – Tues, Sept 13, 2022.
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