This phase II trial studies how well lutetium Lu 177 dotatate works in treating patients with prostate cancer with neuroendocrine differentiation that has spread to other places in the body (metastatic). Neuroendocrine differentiation refers to cells that have traits of both hormone-producing endocrine cells and nerve cells. These cells release hormones into the blood in response to a signal from the nervous system. Hormones are biological substances that circulate through the bloodstream to control the activity of other organs or cells in the body. Lutetium Lu 177-dotatate is a radioactive drug. It binds to a protein called somatostatin receptor, which is found on some neuroendocrine tumor cells. Lutetium Lu 177-dotatate builds up in these cells and gives off radiation that may kill them. It is a type of radioconjugate and a type of somatostatin analog. Treatment with Lutetium Lu 177 dotatate may shrink the tumor in a way that can be measured in patients with metastatic prostate cancer with neuroendocrine differentiation.
PRE-REGISTRATION ELIGIBILITY
Histologically confirmed small cell or neuroendocrine cancer from a primary prostate or metastatic biopsy. Neuroendocrine prostate cancer includes mixed small cell with adenocarcinoma histology, as well as small or large cells with positive neuroendocrine markers (e.g., chromogranin or synaptophysin)
Prostate adenocarcinoma with molecular features of neuroendocrine differentiated cancer (e.g., 2 of the following 3: PTEN, TP53, or RB loss)
Progression of visceral metastases in the absence of PSA progression
Patients who are receiving any other investigational agents
History of allergic reactions attributed to compounds of similar chemical or biologic composition to Lutetium Lu 177 dotatate
As per the Food and Drug Administration (FDA) package insert for Lutetium Lu 177 dotatate, use of long-acting somatostatin analogs (e.g., long-acting octreotide) is prohibited within 4 weeks prior to initiating Lutetium Lu 177 dotatate and during treatment. Use of short-acting somatostatin analogs is prohibited within 24 hours prior to initiating Lutetium Lu 177 dotatate and during treatment. Long-acting somatostatin analogs or short-acting somatostatin analogs will be allowed if the patient has a history of carcinoid syndrome and requires long-acting or short-acting somatostatin analogs for the control of his functional syndrome
Patients with uncontrolled intercurrent illness
Single group
Biospecimen Collection
Procedure/SurgeryUndergo collection of blood
Computed Tomography
Procedure/SurgeryUndergo CT scan
Gallium Ga 68-DOTATATE
RadiationGiven IV
Lutetium Lu 177 Dotatate
DrugGiven IV
Positron Emission Tomography
Procedure/SurgeryUndergo PET
Objective response rate (ORR)
The objective response rate according to Prostate Cancer Working Group (PCWG) 3 criteria will be assessed by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). ORR will be reported along with the corresponding two-sided 95% confidence interval. The confidence interval will be adjusted for the two-stage design structure. This analysis will be based on the intent-to-treat population.
Radiographic progression-free survival (rPFS)
Will be determined by PCWG3 criteria. Specifically, progression/response will be determined via RECIST 1.1 criteria using diagnostic computed tomography (CT) scans of the chest/abdomen/pelvis to analyze progressive disease (PD), stable disease (SD), complete response (CR), partial response (PR), and toxicity type/grade. Progression and response will also be assessed by fludeoxyglucose positron emission tomography (18F-FDG PET).
Treatment response
Will be assessed by 18F-FDG PET.
Change in FDG-PET signal
Will be assessed with Quantitative Total Extensible Imaging.
Gene expression levels of circulating tumor cells
Will be summarized using descriptive statistics. Expression levels of candidate markers will be correlated with radiographic time to progression using univariate Cox proportional hazard regression analysis. The Benjamini-Hochberg false discovery rate method will be utilized to control the false discovery rate when evaluating the markers. Machine learning methods will be used to identify signatures of resistance at the time of progression.
Patient-specific dosimetry of lutetium Lu 177 dotatate
Descriptive analyses will be conducted to evaluate the potential to perform patient-specific dosimetry of lutetium Lu 177 dotatate using gamma imaging to predict treatment response and renal toxicity. Imaging outcome parameters will be summarized in terms of means, medians, standard deviations and ranges, stratified by assessment time point (24, 96, and 192 hours post-injection), stratified by response (PD, SD versus CR, PR) and toxicity type/grade.
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