A Study of Radiation Dosimetry, Safety, and Tolerability of Extended Lutetium (177Lu) Vipivotide Tetraxetan Treatment in Chemo-naïve Adults With Metastatic Castration-resistant Prostate Cancer: RADIOpharmaceutical DOSimetry Evaluation (RADIODOSE) Study

The purpose of the study is to assess and evaluate dosimetry, safety, and tolerability following administration of up to 12 cycles of (177Lu) vipivotide tetraxetan (also referred to as \[177Lu\]Lu-PSMA-617 or 177Lu-PSMA-617 and hereafter identified as AAA617) in taxane-naïve adult participants with PSMA-positive mCRPC who progressed on a prior ARPI treatment with normal renal function or mild renal impairment (eGFR ≥ 60ml/min).

The study includes screening period, treatment period, and a post-treatment follow-up period. Screening Period: Approximately 106 participants will be enrolled to receive up to12 consecutive cycles of AAA617. Potential participants will be assessed for eligibility by verifying their baseline PSMA PET scan for mandatory confirmation of PSMA positivity prior to first cycle by local review. Treatment Period: Eligible participants will be treated with up to 12 cycles of 7.4 GBq AAA617 intravenously every 6 weeks, until radiographic progression, toxicity leading to treatment discontinuation, death, loss to follow-up, or withdrawal of consent, whichever occurs first. During treatment period, all participants who complete the initial 6 cycles of AAA617 treatment will undergo an additional PSMA-PET scan after Cycle 6 to re-assess PSMA expression level and to reassess eligibility of participants to receive additional AAA617 treatment cycles. Post-Treatment Follow-Up: All participants will undergo a PSMA-PET scan at end of treatment (EOT). The post-treatment follow-up period will consist of EOT; 42-days safety; EOT RLI; safety, survival and rPFS follow-up visits. The planned duration of treatment period is up to 74 weeks with treatment given every 6 weeks. Participants may be discontinued from treatment earlier due to unacceptable toxicity or disease progression, and/or at the discretion of the Investigator or the participant.