Exploratory PK and Imaging Study of PSMA-Targeted Trillium Compounds and PTI-122 in Metastatic Prostate Cancer

Ratio Therapeutics

Status and phase: Completed; Early Phase 1

Conditions: Prostate Cancer

Treatments: Drug: PTI-122; Drug: PSMA-Targeted [In-111]-Labeled Trillium Compound

Study type: Interventional

Funder types: Industry

Identifiers

NCT05773703

RTX-PSMA-P101

Details and patient eligibility

About

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.

Enrollment: 23 patients

Sex: Male

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Other

Allocation: Non-Randomized

Interventional model: Sequential Assignment

Masking: None (Open label)

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23 participants in 3 patient groups

Trillium Compound Alone

Experimental group

Description:

Single dose of PSMA-Targeted \[In-111\]-Labeled Trillium Compound

Treatment:

Drug: PSMA-Targeted [In-111]-Labeled Trillium Compound

Trillium Compound + Single Dose PTI-122

Experimental group

Description:

Single dose of PSMA-Targeted \[In-111\]-Labeled Trillium Compound plus single dose of PTI-122 at 5, 10 or 15 mg

Treatment:

Drug: PSMA-Targeted [In-111]-Labeled Trillium Compound

Drug: PTI-122

Trillium Compound + Multiple Dose PTI-122

Experimental group

Description:

Single dose of PSMA-Targeted \[In-111\]-Labeled Trillium Compound plus two doses of PTI-122 at the preferred dose level

Treatment:

Drug: PSMA-Targeted [In-111]-Labeled Trillium Compound

Drug: PTI-122