68Ga-RM2 PET/MRI in Biochemically Recurrent Prostate Cancer

Andrei Iagaru

Status and phase: Completed; Phase 3; Phase 2

Conditions: Prostate Adenocarcinoma

Treatments: Drug: 68Ga-RM2; Procedure: Magnetic Resonance Imaging; Procedure: Positron Emission Tomography

Study type: Interventional

Funder types: Other

Identifiers

NCT02624518

IRB-35155

PROS0074 (Other Identifier)

NCI-2015-01993 (Other Identifier)

Details and patient eligibility

About

Prostate cancer (PC) remains the most-common non-cutaneous cancer diagnosed in American males, accounting for an estimated 174,560 estimated new cases and 31,620 estimated deaths in 2019. Up to 40% of the patients with prostate cancer develop biochemical recurrence within 10 years after initial treatment. Usually an increase of the prostate-specific antigen (PSA) llevel precedes a clinically detectable recurrence by months to years, and this is currently used as a screening test before and subsequent to treatment. However, disease advancement can be local, regional or systemic, and each has significantly different approaches to disease management. Unfortunately, PSA level does not differentiate between these disease stages.

This phase 2-3 study explores the utility of radiolabel 68Ga-RM2, a 68-gallium (68Ga)-labeled gastrin-releasing peptide receptor (GRPr) antagonist, for positron emission tomography (PET) / magnetic resonance imaging (MRI) (collectively, PET/MRI) as a potential tool to help discriminate between disease stages in participants after treatment with surgery or radiation, who present persistently elevated PSA levels (ie, may have prostate cancer), but were negative for cancer with a diagnostic regular medical care computed tomography (CT) scan

68Ga-RM2 (BAY86-7548) is also identified as a synthetic bombesin receptor antagonist. PET/MRI is the collective result of 2 scan processes (PET and MRI ) conducted during the same scan procedure (ie, a combined scan). After a regular medical care computed tomography (CT) scan, participants will be scanned with 68Ga-RM2 PET/MRI scan procedure. PET/MRI is used to assess the location, size, and metabolic activity of a suspected tumor.

The 68Ga-RM2 radiolabel consisted of a ligand (the synthetic bombesin receptor antagonist) and the radioisotope 68Ga. The RM2 ligand targets gastrin-releasing peptide receptors (GRPr), commonly expressed by prostate cancer cells, and the radioisotope distinguishes those cells from the background. The criteria for scan "positivity" will be, when compared to background level of the liver (control), the 68Ga signal is stronger (positive - malignant) or weaker (negative - benign).

This study will assess how well 68Ga-RM2 works in detecting prostate cancer in patients with

68Ga-RM2 PET/MRI may be able to see smaller tumors than the standard of care contrast-enhanced CT or MRI scan.

Full description

PRIMARY OBJECTIVES:

Evaluate 68Ga-RM2 as the radiolabel for PET/MRI scans used for detection of recurrent prostate cancer after initial therapy in patients with elevated prostate-specific antigen (PSA) and non-contributory computed tomography (CT).

OUTLINE:

Patients receive 68Ga-RM2 intravenously (IV) and beginning 45 minutes later undergoing PET/MRI scan. The 68Ga-RM2 PET/MRI may be repeated at the completion of treatment to evaluate response to therapy, if requested by the treating physician.

After completion of study, patients are followed up at 24 to 48 hours and then at 1 year.

Enrollment: 122 patients

Sex: Male

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Biopsy proven prostate adenocarcinoma

• Rising PSA after definitive therapy with prostatectomy or radiation therapy (external beam or brachytherapy

  • Post radical prostatectomy (RP) - American Urological Association (AUA) recommendation

    • PSA greater than 0.2 ng/mL measured 6-13 weeks after RP
    • Confirmatory persistent PSA greater than 0.2 ng/mL

  • Post-radiation therapy - American Society for Therapeutic Radiology and Oncology (ASTRO)-Phoenix consensus definition

    • Nadir plus (+) greater than or equal to 2 ng/mL rise in PSA

• No evidence of metastatic disease on conventional imaging, including a negative bone scan for skeletal metastasis and negative contrast-enhanced CT

• Able to provide written consent

• Karnofsky performance status of >= 50 (or Eastern Cooperative Oncology Group [ECOG]/World Health Organization [WHO] equivalent)

Exclusion criteria

• Unable to provide informed consent
• Inability to lie still for the entire imaging time
• Inability to complete the needed investigational and standard-of-care imaging examinations due to other reasons (severe claustrophobia, radiation phobia, etc.)
• Any additional medical condition, serious intercurrent illness, or other extenuating circumstance that, in the opinion of the investigator, may significantly interfere with study compliance
• Metallic implants

Trial design

Primary purpose: Diagnostic

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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122 participants in 1 patient group

Diagnostic (68Ga-RM2 PET/MRI)

Experimental group

Description:

Patients receive 68Ga-RM2 IV and beginning 45 minutes later undergoing PET/MRI scan. The 68Ga-RM2 PET/MRI may be repeated at the completion of treatment to evaluate response to therapy, if requested by the treating physician. Imaging with PET/MRI is the intervention.

Treatment:

Procedure: Positron Emission Tomography

Procedure: Magnetic Resonance Imaging

Drug: 68Ga-RM2