Minority-Inclusive Imaging Biomarker-Based End of Therapy Trial for 177Lu-PSMA-617, a Randomized De-Escalation Theranostic Trial for Metastatic Castrate Resistant Prostate Cancer
This phase II trial studies how to improve the usage of Lu 177 vipivotide tetraxetan (177Lu-prostate-specific membrane antigen \[PSMA\]-617) for treating patients with castration-resistant prostate cancer that has spread from where it first started (primary site), to other places in the body (metastatic) utilizing a treatment pause after 5 cycles of therapy versus standard continuous treatment for 6 cycles. Lutetium is a radioligand therapy (RLT). RLT uses a small molecule (in this case 177Lu-PSMA-617) that carries a radioactive component to destroy tumor cells. When lutetium is injected into the body, it attaches to the PSMA receptor found on tumor cells. After lutetium attaches to the PSMA receptor, its radiation component destroys the tumor cell. Giving 177Lu-PSMA-617 for 5 cycles versus 6 cycles may better treat patients with metastatic castrate resistant prostate cancer.
• REGISTRATION INCLUSION CRITERIA
• Scheduled at Mayo Clinic Rochester for therapy with 177Lu PSMA-617
• PSMA positive metastatic castration resistant prostate cancer (68Ga and 18F PSMA PET will be considered equivalent for eligibility) , defined by molecular imaging prostate specific membrane antigen (miPSMA) score \>= 2 on Mayo PET report, including interpretation of outside PET or consensus review of PET by nuclear therapy tumor board note in the patient chart
• Willingness to provide mandatory blood draws for correlative research. (This requirement is waived for patients enrolling after receiving cycle 1 of 177Lu PSMA-617,and achieving a near complete response on post therapy SPECT, as these patients will not be able to provide a pre-treatment baseline blood sample.)
• Provide written informed consent
• Ability to complete questionnaire(s) by themselves or with assistance
• Willing to return to enrolling institution for follow-up (during the active monitoring phase of the study)
• RANDOMIZATION INCLUSION CRITERIA
• Lesions with uptake equal to or above liver on cycle 1 post therapy SPECT, demonstrating that a near complete response on follow up post-therapy scan represents response, rather than sensitivity differences between SPECT and pre-treatment PET
• Near-complete response on post-therapy SPECT following any of cycles 2-5 of 177Lu PSMA-617. Near-complete response will be defined as no lesions with SUV max above the mean standard uptake value (SUV) of a representative 2cm spherical region of interest in the central right hepatic lobe, as determined by a nuclear medicine trained radiologist
• No toxicity that would indicate withholding or reducing dose of the next scheduled cycle of 177Lu PSMA-617 per prescribing information
• Hemoglobin (Hgb) ≥ 8 g/dL
• Platelets ≥ 75,000/mm\^3
• Neutrophils ≥ 100/mm\^3
• Estimated glomerular filtration rate (eGFR) \< 50 mL/min \*body surface area (BSA) using Cockcroft-Gault formula OR
• Creatinine ≤ 1.5 x upper limit of normal
• Aspartate transferase (AST) or alanine transaminase (ALT) ≤ 3 x upper limit of normal
• No other unacceptable toxicity in the clinical judgement of the investigators
• RE-REGISTRATION INCLUSION CRITERIA (CROSSOVER TO COMPLETION UPON FIRST PROGRESSION OF PATIENTS RANDOMIZED TO TREATMENT PAUSE)
• First progression in patients randomized to pause treatment
• PSMA avid lesions on PSMA PET (miPSMA score ≥ 2 following first progression)