The study for each participant consisted of a Screening period, a Treatment period and a Follow-up period.
Sub-study A dosimetry, PK and ECG sub-study was conducted in a non-randomized cohort (AAA617+BSC/BSoC) of 30 patients at sites in Germany to provide a more complete assessment of the safety aspects of AAA617. Aside from additional assessments to collect data for dosimetry, PK, urinary metabolites and ECG, patients in the sub-study were screened for eligibility, treated and followed up similarly to the AAA617+BSC/BSoC (investigational arm) patients in the main study.
Screening and randomization:
During the screening period of up to 28 days before starting randomized treatment, each participant was assessed for PSMA positivity by gallium (68Ga) gozetotide imaging PET/scan per the pre-defined read rules, by the Sponsor's central reader. Only patients with PSMA-positive metastatic PC and meeting all other inclusion/exclusion criteria were randomized in a 2:1 ratio to receive either 177Lu-PSMA-617 plus BSC/BSoC or BSC/BSoC only. Randomized patients were stratified on the following factors: LDH level (=\< or \> 260 UI/L), presence of liver metastases (Yes or No), eastern cooperative oncology group (ECOG) score (0-1 or 2) and inclusion of NAAD in the BSC/BSoC (at time of randomization (Yes or No)). Protocol- specified BSC/BSoC for each patient was initiated by the investigating physician prior to patient randomization and maintained throughout the study. On-study changes to BSC/BSoC were allowed and at the discretion of the investigating physician.
Randomized treatment:
"Randomized treatment" in this study refers to AAA617+BSC/BSoC (investigational arm) and BSC/BSoC only (control arm). For the sub-study, "study treatment" refers to AAA617+BSC/BSoC (also referred to as the investigational arm), as no randomization occurred in the sub-study. When discussing aspects of the study which are applicable to both the main and sub-study, the term 'randomized treatment' will be used throughout this document. The term 'study treatment' will be used only when specifically referring to the sub-study.
Patients randomized to the investigational arm began AAA617 dosing within 28 days of randomization. These patients received BSC/BSoC and 7.4 GBq (+/-10%) AAA617 once every 6 weeks (+/- 1 week) for a maximum of 6 cycles.
After the Cycle 4 treatment and prior to Cycle 5 treatment, the Investigator had to determine if:
* The patient showed evidence of response (i.e. radiological, PSA, clinical benefit)
* The patient had signs of residual disease on CT with contrast/MRI or bone scan
* The patient had shown good tolerance to the AAA617 treatment
If the patient met all of the criteria above and agreed to continue with additional treatment of AAA617 the investigator could administer a further 2 cycles. A maximum of 6 cycles of radioligand therapy was allowed. If the patient did not meet any of the criteria or did not agree to additional AAA617 treatment, then no additional doses of AAA617 were administered after Cycle 4. After the last cycle of AAA617, patients continued BSC/BSoC alone, as long as the investigator felt they were clinically benefiting or until they required a treatment regimen not allowed in this study. For both treatment arms, the cycle duration for Cycle 1-6 was 6 weeks and for Cycle 7 and beyond, 12 weeks. From Cycle 7 onwards, all patients from both treatment arms only received BSC/BSoC.
End of treatment:
An End of Treatment (EOT) visit was scheduled approximately 30 days after the last dose of AAA617 or the date of the BSC/BSoC end of treatment decision (whichever occurred later), but before the initiation of subsequent anti-cancer treatment, outside of what was allowed on study. Once a patient discontinued the randomized treatment part of the study for any reason, an EOT visit was scheduled.
Long-term follow-up:
Patients on the active part of the study at the time of the final analysis of OS had an EOT visit at the next planned visit after implementation of V5.0/5.1 of the protocol and moved into long-term follow-up, unless they specifically withdrew consent from long-term follow-up of the study.
Patients who consented to be followed for long-term status updates, entered the long-term follow-up period after the EOT visit. The long-term follow-up period included the collection of rPFS (if the patient discontinued for reasons other than radiographic progression), OS, information about new treatments along with the patient's response to these treatments, AE assessment, and results of hematology and chemistry testing. During the follow-up, patients were contacted every 3 months (+/-1 month) via phone, email, or letter until a long-term follow-up study became available, until death or until withdrawal of consent, whichever occurred first.
