Abstract 5529
Background
The treatment of mCRPC is a major medical challenge. The beta-emitting Lu-177-PSMA radioligand therapy (RLT) is a new option but its antitumor effect can decrease over time. The aim of this retrospective analysis was to investigate safety and efficacy of the alpha emitting Ac-225-PSMA-617 RLT in mCRPC after Lu-177-PSMA failure.
Methods
At data analysis 03/19 18 patients (pts) underwent Ac-225-PSMA-617 RLT between 10/17 and 12/18. All pts had previously received second line antihormonal treatment and 17/18 pts taxane based chemotherapy. All pts had shown progression after Lu-177-PSMA therapy (median 2 cycles). High PSMA-expression of the tumor lesions in PSMA-PET/CT before Ac-225-PSMA-617 was mandatory. Pts were treated at 8 weekly intervals until progression or intolerable side effects. Prostate-specific antigen (PSA) and blood cell count were measured every 2-3 weeks. We report updated data of hematological and non-hematological side effects, biochemical response and a subgroupanalysis.
Results
A total of 36 cycles of Ac-225-PSMA-617 (median dose 8 MBq, range 4,4–12.8) were applied. 7 pts received only 1 cycle, 5 pts 2 cycles, 5 pts 3 cycles and 1 patient 4 cycles. Baseline PSA was 822 ng/ml (range 49–4073). ECOG score was grade 0, 1 and 2 in 3, 13 and 2 pts. 15/18 pts showed any PSA-decline, 5/18 a PSA-decline of more than 50% and 3 pts no PSA-decline at any time. 6 weeks after treatment 12/18 showed any PSA decline and 4/18 a PSA-decline of > 50%. Grade 1 xerostomia occurred in 17 and grade 2 in 1 patient. 6/18 pts (33%) requested to stop treatment due to xerostomia. 2 pts developed grade 2 renal insufficiency, 5 pts grade 3-4 anemia, 2 pts grade 3-4 thrombocytopenia and 2 pts 3-4 leucopenia. 7/18 pts died during the observation period (median overall survival 9,6 months). The PSA-progression free survival was 1,3 months. In a subgroupanalysis of 9 pts with a rapid progression under a previous Lu-177-PSMA treatment 7 pts achieved any PSA-decline and 4 pts a decline of more than 50%.
Conclusions
In this small cohort Ac-225-PSMA-617 RLT showed antitumor effect in mCRPC after Lu-177-PSMA failure even after rapid tumour progression. However, treatment had to be stopped in one third of the pts due to xerostomia.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4900 - Molecular profiling and prognostic significance of TP53 mutations in Diffuse Large B Cell Lymphoma: identifying a high-risk subgroup
Presenter: Yuan-Kai Shi
Session: Poster Display session 3
Resources:
Abstract
3809 - Differential expression of various miRNAs in Pediatric Cytogenetically Normal Acute Myeloid Leukemia (CN-AML)
Presenter: Vikas Gaur
Session: Poster Display session 3
Resources:
Abstract
4750 - Circulating tumour cells in head and neck and non-small cell lung cancer
Presenter: Kenneth O'Byrne
Session: Poster Display session 3
Resources:
Abstract
3704 - OX40/OX40L protein expression in Non-small cell lung cancer and its role in clinical outcome and relationships with other immune biomarkers
Presenter: Xiaoshen Zhang
Session: Poster Display session 3
Resources:
Abstract
2235 - Effect of Serum Survivin on Survival among Non-Small Cell Lung Cancer Patients; NCI Experience
Presenter: Reham Rashed
Session: Poster Display session 3
Resources:
Abstract
2788 - Enhanced performance of prognostic estimation from TCGA RNAseq data using transfer learning.
Presenter: Helene Vanacker
Session: Poster Display session 3
Resources:
Abstract
4689 - Analysis of Circulating Tumor DNA for Early Relapse Detection in Stage III Colorectal Cancer After Adjuvant Chemotherapy
Presenter: Samuel Jacobs
Session: Poster Display session 3
Resources:
Abstract
1454 - Ascites-derived circulating microRNAs as potential diagnostic biomarkers of gastric cancer-associated malignant ascites
Presenter: Hye Sook Han
Session: Poster Display session 3
Resources:
Abstract
5574 - Results from TRIO030, a Pre-Surgical Tissue-Acquisition Study to Evaluate Molecular Alterations in Human Breast Cancer Tissue Following Short-Term Exposure to the Androgen Receptor Antagonist Darolutamide
Presenter: Hsiao-Wang Chen
Session: Poster Display session 3
Resources:
Abstract
1787 - JMJD2A is a novel epigenetic factor of chemotherapeutic susceptibility in gastric cancer
Presenter: Yasushi Sato
Session: Poster Display session 3
Resources:
Abstract