Low PSMA SUV Boost (LPS-Boost): Intensified 177Lu-PSMA-617 Treatment for Patients With Metastatic Castrate-Resistant Prostate Cancer With Low PSMA Expressing Disease

OUTLINE: Patients receive 177Lu-PSMA-617 intravenously (IV) over 30 minutes on days 1, 8, 50, 57, 99 and 141. Treatment repeats every 7 days for cycles 1 and 3 and every 6 weeks for cycle 2 and subsequent cycles for up to 6 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo PSMA positron emission tomography/computed tomography (PET/CT) during screening and single photon emission computed tomography (SPECT)/CT on study. Patients also undergo CT or magnetic resonance imaging (MRI), bone scan, as well as blood sample collection throughout the study. After completion of study treatment, patients are followed up at 30 days and then every 12 weeks for up to 2 years.