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
2929 - Changes of the Commensal Microbiome during Treatment are Associated with Clinical Response in the Nasopharyngeal Carcinoma Patients
Presenter: Tingting Huang
Session: Poster Display session 3
Resources:
Abstract
2888 - Development and validation a nomogram based on pathological microscopic features to predict survival in nasopharyngeal carcinoma and guide treatment decision
Presenter: Kuiyuan Liu
Session: Poster Display session 3
Resources:
Abstract
3607 - Deep learning in nasopharyngeal carcinoma: a retrospective cohort study of 3D convolutional neural networks on magnetic resonance imaging
Presenter: Meng Yun Qiang
Session: Poster Display session 3
Resources:
Abstract
5848 - Combined androgen blockade in patients with advanced androgen receptor–positive salivary gland carcinoma: Exploratory biomarker analyses
Presenter: Chihiro Fushimi
Session: Poster Display session 3
Resources:
Abstract
4484 - Classification of esthesioneuroblastoma (ENB) based on chromosome (chr) arm gain and loss (CNA) in the setting of a hypomutated genomic landscape
Presenter: Russell Madison
Session: Poster Display session 3
Resources:
Abstract
5753 - Trastuzumab plus docetaxel in patients with advanced HER2–positive salivary duct carcinoma: Exploratory biomarker analyses
Presenter: Hideaki Takahashi
Session: Poster Display session 3
Resources:
Abstract
3373 - Development and characterization of salivary gland cancer organoid cultures
Presenter: Wim Boxtel
Session: Poster Display session 3
Resources:
Abstract
3118 - A parent-of-origin effect of the RB1 mutations in retinoblastoma with low penetrance and variable expressivity
Presenter: Ekaterina Alekseeva
Session: Poster Display session 3
Resources:
Abstract
4512 - The humanistic burden reported by patients diagnosed with Recurrent/Metastatic Squamous Cell Carcinoma of the Head and Neck (R/M SCCHN) in Europe
Presenter: Prianka Singh
Session: Poster Display session 3
Resources:
Abstract
3961 - Concurrent Chemotherapy and External Radiation Therapy: An Open Label Non-Inferiority Phase III Randomized Controlled Trial of Weekly versus Three Weekly Cisplatin and Radical Radiotherapy in Locally Advanced Head and Neck Squamous Cell Carcinoma: CONCERT trial
Presenter: ATUL SHARMA
Session: Poster Display session 3
Resources:
Abstract