177-Lutetium-PSMA Before Stereotactic Body Radiotherapy for the Treatment of Oligorecurrent Prostate Cancer, The LUNAR Study

PRIMARY OBJECTIVE: I. To assess progression-free survival for men with oligorecurrent prostate cancer after stereotactic body radiotherapy (SBRT) versus SBRT plus neoadjuvant lutetium Lu-177 PNT2002 (177Lu-PNT2002), with progression defined on the basis of prostate-specific membrane antigen positron emission tomography/computerized tomography (PSMA PET/CT) scans obtained at standard intervals (12 months and 24 months post-SBRT) or at the time of prostate-specific antigen (PSA)-based biochemical progression, or initiation of salvage therapy or death. SECONDARY OBJECTIVES: I. To evaluate disease burden of disease (including local control of irradiated lesions and presence of other disease) on a PSMA PET/CT obtained 24 months after SBRT of SBRT versus SBRT + 177Lu-PNT2002 in patients with oligometastatic disease who have not progressed by that point. II. To assess physician-scored toxicity (Common Terminology Criteria for Adverse Events version 5.0 \[CTCAE v 5.0\]) of SBRT versus SBRT + 177Lu-PNT2002 in patients with oligometastatic disease. III. To assess patient-reported quality of life (based on the brief pain inventory scale) after SBRT versus SBRT + 177Lu-PNT2002 in patients with oligometastatic disease. IV. To assess androgen deprivation therapy (ADT)-free survival after SBRT versus SBRT + 177Lu-PNT2002 in patients with oligometastatic disease. V. To determine local control of irradiated lesion at 12 months after SBRT versus SBRT + 177Lu-PNT2002 in patients with oligometastatic disease (based on a scheduled PSMA-PET). VI. To assess time to locoregional progression, time to distant progression, time to new metastasis, and duration of response after SBRT versus SBRT + 177Lu-PNT2002 in patients with oligometastatic disease (based on standard of care imaging). CORRELATIVE OBJECTIVES: I. To enumerate circulating tumor cells (CTCs) and circulating tumor deoxyribonucleic acid (ctDNA) at baseline, 3 months, 6 months, and 12 months after SBRT. II. To quantitatively sequence T-cell receptor (TCR) repertoires using peripheral blood monocytes at baseline, 3 months, 6 months, and 12 months after SBRT. III. To perform radiomics analysis on PSMA PET/CT scans performed at +12 months (mo.), +24 months post-SBRT, or at time of progression. OUTLINE: Patients are randomized to 1 of 2 arms. ARM 1: Beginning on day 1, patients undergo SBRT to all lesions for 1, 3, or 5 treatment doses (fractions) over the span of 10-20 days in the absence of disease progression or unacceptable toxicity. ARM 2: Patients receive 177Lu-PNT2002 intravenously (IV) over 1-10 minutes on days -112 and -56 in the absence of disease progression or unacceptable toxicity. Beginning on day 1, patients then undergo SBRT to all lesions for 1, 3, or 5 treatment doses (fractions) over the span of 10-20 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment patients are followed up at 1, 3, 6, 9, and 12 months, then every 6 months until 60 months of total follow-up.