(P 535) THERAGNOSTICS IN SOFT TISSUE SARCOMA USING A VASCULAR DISCRUPTION APPROACH

Objective: Patients with advanced soft tissue sarcomas (STSs) have very poor prognosis and systemic chemotherapy is the mainstay of therapy. Prostate-specific membrane antigen (PSMA) is highly expressed on the vasculature of several solid tumor, including 20% of STS, participating in neovessel growth in developing tumors. We therefore hypothesize that uptake in Ga-68- PSMA-11 PET/CT correlates with PSMA positive tumor neovascularization. Our single center clinical trial aims to evaluate feasibility and efficacy of Lu-177-ITG-PSMA-1 in advanced heavily treated patients with STS. (ClinicalTrials.gov identifier: NCT05420727).

Methods: Patients with STS who progressed after a maximum of two lines of standard treatment with ECOG 0-2 and a life expectancy of >3 months and adequate organ function have been included. The primary objective is the evaluation of tumor growth as judged by the imaging result obtained on Ga-68-PSMA-11 PET/CT scan four weeks after the second cycle of Lu-177-ITG-PSMA-1 treatment, compared to baseline. Secondary endpoints include progression-free survival (PFS), adverse events (AEs), overall survival (OS) and changes in immunological markers.
A total of 20 STSs treated at our center will be screened employing PSMA-targeting ligand Ga-68-PSMA-11. Positive patients will be treated with two cycles of Lu-177-ITG-PSMA-1 six weeks apart. A total of 5 patients are expected; accrual is ongoing. Results are expected in 2024.

Results: N/A Trials in Progress.

Conclusion: N/A Trials in Progress.