Dynamic Assessments of Molecular Response to Guide Early 177Lu-PSMA-617 Treatment Discontinuation: The DYNAMO Study
University of Washington
Summary
This clinical trial studies whether measuring circulating tumor deoxyribonucleic acid (ctDNA) tumor fraction (TF) can be used to help guide the early stopping (discontinuation) of lutetium Lu 177 vipivotide tetraxetan (177Lu-PSMA-617) in patients with castration-resistant prostate cancer that has spread from where it first started (primary site) to other places in the body (metastatic). Many types of tumors tend to lose cells or release different types of cellular products including their deoxyribonucleic acid, which is referred to as ctDNA, into the bloodstream before changes can be seen on scans. Health care providers can measure the level of ctDNA in blood or other bodily fluids to determine which patients are at higher risk for the disease to grow, spread, or get worse or come back after a period of improvement. ctDNA TF is a type of ctDNA measurement. Research has shown ctDNA TF may be a promising way to predict which patients will respond to 177Lu-PSMA-617 treatment. Measuring ctDNA TF may help doctors identify which patients may benefit from changing treatments sooner, which may be an effective way to guide early 177Lu-PSMA-617 treatment discontinuation in patients with metastatic castration-resistant prostate cancer.
Description
OUTLINE: CYCLES 1 AND 2: Patients receive 177Lu-PSMA-617 intravenously (IV) over 20-30 minutes on day 1 of each cycle. Cycles repeat every 6 weeks for up to 2 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo blood sample collection with ctDNA TF testing at baseline and C2D1. Patients with undetectable ctDNA TF (\< 3%) on C2D1 continue to receive 177Lu-PSMA-617 as above in the absence of disease progression or unacceptable toxicity. Patients with detectable ctDNA TF (≥ 3%) on C2D1 are randomized to 1 of 2 arms. CYCLE 3+ ARM I: Starting with cycle 3,…