Exploratory study in adult males with metastatic prostate cancer intended to characterize the pharmacokinetics and biodistribution of PSMA-Targeted [In-111]-Labeled Trillium Compounds with and without the cytoprotective agent PTI-122. Up to 36 eligible subjects will be enrolled. Additional subjects may be enrolled if there is insufficient data for evaluation, for example if the original study subjects do not complete required imaging studies for reasons unrelated to adverse events.

Up to four PSMA-Targeted [In-111]-Labeled Trillium Compounds will be evaluated. Each compound will be evaluated first without the cytoprotective agent, PTI-122, then the [In-111]-labeled Trillium Compound may be co-administered with PTI-122.

Inclusion Criteria:

• Adult males with metastatic prostate cancer

• ECOG performance score 0-2

• Stable androgen deprivation or other hormone therapy (30 days) or therapy planned but not yet initiated

• PSMA PET scan between 3 and 28 days prior to radiotracer injection with at least 2 PSMA positive lesions and either:

  1. One soft tissue lesion measuring ≥ 15 mm in the longest diameter with SUVmax lesion ≥ SUVmean normal liver, OR
  2. Two bone lesions measuring ≥ 15 mm in the longest diameter with SUVmax lesion ≥ 2 x SUVmax normal liver

• Able to understand and adhere to study requirements, and voluntarily give informed consent

Exclusion Criteria:

• No other malignancy undergoing treatment
• No PSMA-targeted therapy ongoing
• Inability or unwillingness to undergo SPECT/CT imaging
• Serum creatinine > 1.5 mg/dL or creatinine clearance ≤50 mL/min by Cockcroft-Gault estimation
• Concurrent participation in the active treatment phase of another clinical trial of investigational medicinal product(s)
• Significant intercurrent illness, treatment-related toxicity, or psychiatric illness/social situation that could place the subject at undue risk during study participation, significantly alter study outcomes, or affect subject compliance with study requirements for dosing and evaluation, as determined by the investigator

Males with prostate cancer