Abstract 629P
Background
Prostate-specific membrane antigen (PSMA) targeted radionuclide therapy (TRT) is a promising investigational therapy for patients with progressive metastatic castration-resistant prostate cancer. PSMA TRT conjugates a radionuclide emitting alpha radiation (e.g., Actinium-225) or beta radiation (e.g., Lutetium-177) to a small molecule ligand (e.g., PSMA-617) or a monoclonal antibody (e.g., J591) that has affinity for PSMA. Treatment is generally well-tolerated, but adverse events have been reported. We aimed to assess patient reported outcomes in prospective clinical trials.
Methods
From 2017 to 2021, 79 receiving either 177Lu-PSMA-617 or 225Ac-J591 with complete FACT-P and BPI instruments at baseline and 12 weeks later. We used linear mixed model analyses with no imputation for missing data among participants with evaluable data to examine whether PROs changed over time and whether change in PROs was associated with treatment received, baseline clinical factors, and response to treatment (i.e., best change in PSA after baseline).
Results
91% receiving 177Lu-PSMA-617 and 100% receiving 225Ac-J591 experienced at least one adverse event, such as pain, fatigue, dry mouth, nausea, and hematologic toxicity. No overall change over time was observed in quality of life or pain (Ps > .05), and treatment (i.e., 177Lu-PSMA-617 vs. 225Ac-J591) was not associated with change in PROs (Ps > .05). Baseline factors (e.g., ECOG performance status, metastases) were not associated with change over time in PROs (Ps > .05). Response to treatment was associated with change over time in pain intensity, functional well-being, prostate-specific quality of life, and overall quality of life.
Conclusions
This is the first study we are aware of to compare change in PROs among patients receiving different TRT therapies. PROs did not change over time overall or as a function of PSMA-TRT received; however, change in clinically important PROs was associated with response to treatment. Future studies should replicate and extend these findings to examine change in PROs as a potential prognostic factor for response to PSMA-TRT.
Clinical trial identification
NCT03042468, NCT03276572.
Editorial acknowledgement
Legal entity responsible for the study
Weill Medical College of Cornell University.
Funding
Department of Defense, Prostate Cancer Foundation.
Disclosure
B.D. Gonzalez: Financial Interests, Personal, Other, Consultant: SureMed Compliance; Financial Interests, Personal, Stocks/Shares: Elly Health; Financial Interests, Personal, Other, Consultant: KemPharm. N. Bander: Financial Interests, Personal, Leadership Role: BZL Biologics. S.T. Tagawa: Financial Interests, Personal, Research Grant: Novartis; Financial Interests, Personal, Advisory Board: Novartis; Financial Interests, Personal, Research Grant: Bayer; Financial Interests, Personal, Advisory Board: Bayer. All other authors have declared no conflicts of interest.