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

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.

Sex

Male

Minimum age

18 Years

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

• BACKGROUNDBaratto L, Song H, Duan H, Hatami N, Bagshaw HP, Buyyounouski M, Hancock S, Shah S, Srinivas S, Swift P, Moradi F, Davidzon G, Iagaru A. PSMA- and GRPR-Targeted PET: Results from 50 Patients with Biochemically Recurrent Prostate Cancer. J Nucl Med. 2021 Nov;62(11):1545-1549. doi: 10.2967/jnumed.120.259630. Epub 2021 Mar 5. PMID 33674398
• RESULTBaratto L, Duan H, Laudicella R, Toriihara A, Hatami N, Ferri V, Iagaru A. Physiological 68Ga-RM2 uptake in patients with biochemically recurrent prostate cancer: an atlas of semi-quantitative measurements. Eur J Nucl Med Mol Imaging. 2020 Jan;47(1):115-122. doi: 10.1007/s00259-019-04503-4. Epub 2019 Sep 2. PMID 31478089
• DERIVEDDuan H, Moradi F, Davidzon GA, Liang T, Song H, Loening AM, Vasanawala S, Srinivas S, Brooks JD, Hancock S, Iagaru A. 68Ga-RM2 PET-MRI versus MRI alone for evaluation of patients with biochemical recurrence of prostate cancer: a single-centre, single-arm, phase 2/3 imaging trial. Lancet Oncol. 2024 Apr;25(4):501-508. doi: 10.1016/S1470-2045(24)00069-X. Epub 2024 Feb 26. PMID 38423030
• DERIVEDDuan H, Davidzon GA, Moradi F, Liang T, Song H, Iagaru A. Modified PROMISE criteria for standardized interpretation of gastrin-releasing peptide receptor (GRPR)-targeted PET. Eur J Nucl Med Mol Imaging. 2023 Nov;50(13):4087-4095. doi: 10.1007/s00259-023-06385-z. Epub 2023 Aug 9. PMID 37555901
• DERIVEDDuan H, Baratto L, Hatami N, Liang T, Levin CS, Khalighi MM, Iagaru A. Reduced Acquisition Time per Bed Position for PET/MRI Using 68Ga-RM2 or 68Ga-PSMA-11 in Patients With Prostate Cancer: A Retrospective Analysis. AJR Am J Roentgenol. 2022 Feb;218(2):333-340. doi: 10.2214/AJR.21.25961. Epub 2021 Aug 18. PMID 34406051