Evaluate the Clinical Usefulness of [F-18]Florastamin PET/CT Imaging Diagnosis Compared to MRI Diagnosis

Only in subjects who satisfy the inclusion/exclusion criteria, a single dose of \[F-18\]Florastamin at 10 ± 1 mCi is IV administered at Visit 2, and \[F-18\]Florastamin PET/CT images are obtained from the head to thigh after 110 ± 10 minutes.

Once a subject provides voluntary written consent on participation in this study, the investigator conducts screening of the subject. Subsequently, MRI and \[F-18\]Florastamin PET/CT are performed for each patient, only for those who satisfy the inclusion/exclusion criteria. For MRI at Visit 2, routine MRI, as implemented in the Urology Department, is performed in the abdomen and pelvis. On the date of or within 7 days after MRI, a single dose of \[F-18\]Florastamin at 10 ± 1 mCi is IV administered to a subject, and PET/CT images are obtained from the head to thigh after 110 ± 10 minutes (care should be taken to prevent extravasation of the radiopharmaceutical product). At Visit 3, the principal investigator or a treating doctor as delegated by the principal investigator conducts the template prostate-mapping (TPM) biopsy in at least the Modified Barzell 20-zone using the standard template. After general anesthesia or spinal anesthesia, the tissue is collected by horizontally sticking a histological needle through the perineum, and the process can be performed as in-patient, at the discretion of the investigator.

The MRI finding is determined positive for a lesion with the PI-RADS score of 3 or higher, and the \[F-18\]Florastamin PET/CT finding is considered positive for the focal uptake higher than the background level and unrelated with the physiologic uptake or known pitfall.

MRI and \[F-18\]Florastamin PET/CT images are sent to the central reading institution, Seoul St. Mary's Hospital, after blinding for the study information. Suspected sites on MRI are evaluated at the Seoul St. Mary's Hospital Radiology Department, and the suspected sites on \[F-18\]Florastamin PET/CT are assessed at the Seoul St. Mary's Hospital Nuclear Medicine Department. Note that the \[F-18\]Florastamin PET/CT rater would participate in the assessment after undergoing sufficient training with \[F-18\]Florastamin PET/CT images from a Phase 1 study of the same product.

A pathologist at each center will conduct diagnosis of prostate cancer for TPM biopsy samples from the entire prostate volume. Target biopsy of MRI and \[F-18\]Florastamin PET/CT will not be performed. By comparing confirmed sites from each imaging diagnosis method and positive/negative results for prostate cancer from TPM biopsy diagnosis, the proportions of True Positive (TP), False Positive (FP), True Negative (TN), False Negative (FN) will be analyzed and the sensitivity, specificity, negative predictive value, positive predictive value, and diagnostic accuracy will be compared using a 2x2 contingency table.

Eligibility Criteria:
Inclusion Criteria:

1. Adult men aged at least 20 years determined to be at the high risk of prostate cancer based on screening diagnosis performed at the Urology Department (Patients who require prostate histology due to abnormal digital rectal examination (DRE) or abnormal PSA levels, etc., and have a palpable node during DRE or satisfy PSA\>3.0 ng/mL)
2. Subjects who were not previously diagnosed with prostate cancer at the time of screening
3. Subjects who can conduct prostate histology
4. Subjects with the ECOG Performance score of ≤2 at screening
5. Subjects who satisfy the following conditions for hematology, kidney function test and liver function test

   ① Platelets \> 50,000/mm3

   ② BUN and serum creatinine \< 1.5 x upper limit of normal (ULN)

   ③ AST and ALT \< 2.5 x upper limit of normal (ULN)

   ④ PT (INR) or aPTT \< 1.5 x upper limit of normal (ULN)
6. Subjects who were fully informed by the investigator about the objectives, details of the study and characteristics of the study drug, etc. during the screening visit and provide voluntary written consent to take part in this study

Exclusion Criteria:

1. Subjects who were previously diagnosed with prostate cancer
2. Subjects with a history of acute urinary retention, urinary tract infection or other urinary infection within 4 weeks of screening
3. Subjects who conducted cystoscopy, urethral catheter procedure or colonoscopy within 4 weeks of screening
4. Subjects who conducted prostate histology or prostate surgery (other than treatment for prostate hyperplasia or bladder outlet obstruction) or androgen deprivation therapy (ADT) within 1 year of screening
5. Subjects who received 5-alpha reductase inhibitors within 3 months of screening or currently on them at screening
6. Subjects with hypersensitivity to any component of the radiopharmaceutical product
7. Subjects determined by the investigator to have difficulty in conducting the study due to serious medical disease
8. Subjects determined by the investigator to have difficulty in lying still for 30-60 minutes in a supine position for radiography (CT, MRI, etc.) (example: panic disorder) or have psychiatric disorder causing difficulty in imaging
9. Subjects who are planned to administer contraindicated concomitant medication (antiplatelet agents/anticoagulants, thrombolytics or circulatory improvement agents) between 5 days before biopsy and \[Visit 3 + 3D\]
10. Subjects who are otherwise determined to be ineligible to take part in this study at the medical discretion of the investigator