Assessing Efficacy of Neoadjuvant ADT in Localized High-Risk Prostate Cancer Patients Utilizing 18F-Flotufolastat PSMA PET/CT

Assessing the Efficacy of Neoadjuvant Androgen Deprivation Therapy (ADT) Utilizing 18F-Flotufolastat PSMA PET/CT in Patients With High-Risk Localized Prostate Cancer (LHRPC)

The purpose of this research study is to test the efficacy of ADT on prostate-specific membrane antigen (PSMA), a marker of prostate cancer, before and after scheduled ADT. Follow up will be 48 months your prostate removal to do a blood test and log if any new or worsening symptoms have occurred as a part of your standard-of-care (SOC).

This is a single-arm, phase II, open label study in patients with localized high- risk prostate cancer (LHRPC) treated with neoadjuvant ADT (leuprolide, degarelix, relugolix, or triptorelin) followed by radical prostatectomy (RP). This study aims to evaluate the efficacy of neoadjuvant ADT based on maximal standardized uptake value (SUVmax) changes on 18F-Flotufolastat prostate- specific membrane antigen (PSMA) PET/CT scan in patients with LHRPC. Additionally, it will investigate the prognostic value of SUVmax changes in predicting biochemical recurrence-free survival.

Inclusion Criteria:

• Signed informed consent must be obtained prior to participation in the study.

• Males aged ≥18 years.

• ECOG performance status ≤ 1

• Histologically confirmed adenocarcinoma of the prostate in a patient amenable to radical prostatectomy

• Pathologically proven prostate adenocarcinoma with ≥ 1 High-risk feature based on NCCN guidelines.

  1. cT3-cT4
  2. International Society of Urological Pathology (ISUP) Grade group 4 (Gleason score 8) or grade group 5 (Gleason score 9-10)
  3. PSA >20 ng/mL

• Clinically negative lymph nodes as established by PSMA PET/CT imaging. Patients who are node positive by PSMA PET/CT (e.g., N1), but whose nodes do not meet traditional size criteria for positivity (e.g., they measure ≥ 10mm on either the CT or MRI portion of the PET or on a dedicated CT or MRI) will not be considered N1 and would be eligible for this study.

• Patient is willing to use barrier-method of contraception along with another effective contraceptive method if engaged in sexual activity with a pregnant person or individual of childbearing potential (until 1 week after completing 18F-flotufolastat PSMA PET/CT Scans.

• Clinical laboratory values during screening:

  1. Hemoglobin ≥ 10.0 g/dL
  2. Absolute neutrophil count (ANC) ≥ 1.8 × 10⁹/L
  3. Platelets ≥ 100 × 10⁹/L

Exclusion Criteria:

• Known allergies, hypersensitivity, or intolerance to 18F-flotufolastat.

• Unable to receive androgen deprivation therapy.

• Prostate cancer with significant neuroendocrine or other rare variant pathology

• Evidence of metastatic disease involving bone, viscera, or lymph nodes superior to the bifurcation of the common iliac arteries on PSMA PET/CT

• Renal impairment (glomerular filtration rate <30 mL/min)

• History of prior radiation therapy for prostate cancer

• Any of the following within 6 months prior to the first dose of study treatment: severe or unstable angina, myocardial infarction, symptomatic congestive heart failure, clinically significant ventricular arrhythmias, or New York Heart Association Class II to IV heart disease.

• Uncontrolled severe hypertension, persistent uncontrolled diabetes, oxygen-dependent lung disease, chronic liver disease, or untreated HIV infection.

• Other malignancies other than prostate cancer in the past 5 years

  a. Cured basal cell or squamous cell skin cancers can be enrolled.

• Severe or uncontrolled concurrent infections are not eligible.

• Treated with concomitant cytotoxic cancer therapy for any other primary site.

• Patients who are unable to complete the study requirements of 2nd PSMA imaging or surgery for the primary endpoints.

• Any condition that, in the opinion of the investigator, would preclude participation in this study.