99mTc-PSMA-I&S Biodistribution in Patients With Prostate Cancer

Early Phase 1

Recruiting

• Conditions: Prostate Carcinoma; Recurrent Prostate Carcinoma
• Interventions: Drug: 99mTc-based PSMA Imaging and Surgery Agent; Procedure: Computed Tomography; Procedure: Single Photon Emission Computed Tomography

• Registration Number: NCT04857502
• Lead Sponsor: Jonsson Comprehensive Cancer Center

Brief Summary

This exploratory study conducted under the RDRC program studies the biodistribution of 99mTc-PSMA-I\&S in patients with prostate cancer who undergo pelvic lymph node dissection. Prostate specific membrane antigen (PSMA)-targeted radio-guided surgery uses the preoperative intravenous administration of a PSMA-ligand called PSMA-imaging and surgery (I\&S) labeled with the gamma-emitter radioisotope Technetium-99m (99mTc). Giving 99mTc-PSMA-I\&S may detect PSMA-expressing lymph nodes during surgery using a gamma probe and may help guide doctors to detect prostate cancer that has spread to the lymph nodes.

Detailed Description

PRIMARY OBJECTIVE:

I. To define the biodistribution of 99mTc-based PSMA imaging and surgery agent (99mTc-PSMA-I\&S) in normal and malignant tissues of patients with prostate cancer (PCa) with histopathology validation, when available.

SECONDARY OBJECTIVES:

I. To correlate the 99mTc-PSMA-I\&S accumulation within tumor lesions observed by in-vivo single-photon emission computed tomography (SPECT), ex-vivo gamma measurements and level of prostate-specific membrane antigen (PSMA) expression quantified by histopathology, when available.

II. To define the best time-point for radio-guided surgery (RGS) with the highest tumor-to-background ratio following 99mTc-PSMA-I\&S administration.

OUTLINE:

The first 5 patients receive an initial dose of 99mTc-PSMA-I\&S intravenously (IV) followed by 5 SPECT/CT scans at 3-5, 5-20, 17-21, 25-29, and 40-46 hours later. These 5 patients then receive a second dose of 99mTc-PSMA-I\&S IV and then undergo standard of care surgery. All subsequent patients receive one dose of 99mTc-PSMA-I\&S IV before surgery.

Study Timeline

• Study First Submitted: 2021-04-01
• Study First Submitted QC: 2021-04-20
• Study First Posted: 2021-04-23
• Study Start: 2021-04-27
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-07
• Last Update Posted: 2025-01-09
• Primary Completion: 2025-06-01
• Study Completion: 2026-06-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Male
• Target Recruitment: 30

Inclusion Criteria

• Men with PCa (primary or recurrent disease)
• Men who received a 68Ga-PSMA-11 positron emission tomography (PET)/computed tomography (CT) for staging or restaging
• Men with evidence of lymph nodes (LNs)-positive disease on 68Ga-PSMA-11 PET/CT
• Men who are scheduled for pelvic LN dissection (PLND)
• Men who can provide oral and written informed consent
• Men who can comply with study procedures

Exclusion Criteria

• Patients who started any PCa treatment between study enrollment and surgery
• Technically inaccessible nodal location

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Diagnostic (99mTc-PSMA-I&S, SPECT/CT)	99mTc-based PSMA Imaging and Surgery Agent	The first 5 patients receive an initial dose of undergo 99mTc-PSMA-I\&S IV followed by 5 SPECT/CT scans at 3-5, 5-20, 17-21, 25-29, and 40-46 hours later. These 5 patients then receive a second dose of 99mTc-PSMA-I\&S IV and then undergo standard of care surgery. All subsequent patients receive one dose of 99mTc-PSMA-I\&S IV before standard of care surgery.
Diagnostic (99mTc-PSMA-I&S, SPECT/CT)	Single Photon Emission Computed Tomography	The first 5 patients receive an initial dose of undergo 99mTc-PSMA-I\&S IV followed by 5 SPECT/CT scans at 3-5, 5-20, 17-21, 25-29, and 40-46 hours later. These 5 patients then receive a second dose of 99mTc-PSMA-I\&S IV and then undergo standard of care surgery. All subsequent patients receive one dose of 99mTc-PSMA-I\&S IV before standard of care surgery.
Diagnostic (99mTc-PSMA-I&S, SPECT/CT)	Computed Tomography	The first 5 patients receive an initial dose of undergo 99mTc-PSMA-I\&S IV followed by 5 SPECT/CT scans at 3-5, 5-20, 17-21, 25-29, and 40-46 hours later. These 5 patients then receive a second dose of 99mTc-PSMA-I\&S IV and then undergo standard of care surgery. All subsequent patients receive one dose of 99mTc-PSMA-I\&S IV before standard of care surgery.

Primary Outcome Measures

Name	Time	Method
The biodistribution of 99mTc-PSMA-I&S in normal and malignant tissues of patients with prostate cancer will be measured by average and maximum standardized uptake value (SUVmean and SUVmax)	time from injection to imaging (range: 1-46 hours)

Secondary Outcome Measures

Name	Time	Method
The best time-point for 99mTc-PSMA-I&S radioguided surgery will be determined by the tumor-to-background uptake ratio (TBR) using the time-activity curve function	time from injection to imaging (range: 1-46 hours)
99mTc-PSMA-I&S accumulation within tumor lesions observed by in-vivo SPECT (SUVmean and SUVmax) will be correlated with ex-vivo gamma measurements (counts/minute) and level of PSMA expression quantified by histopathology (IHC score)	time from injection to imaging (range: 1-46 hours)

Trial Locations

Locations (1)

UCLA / Jonsson Comprehensive Cancer Center; 🇺🇸 Los Angeles, California, United States