NEPC Study: An Exploratory Safety and Efficacy Study With PSMA, SSTR2 and GRPR Targeted Radioligand Therapy in Metastatic Neuroendocrine Prostate Cancer.

Key Inclusion criteria:

• Participants must have metastatic prostate cancer with neuroendocrinedifferentiation as determined by at least one of the following:

1. Histologically small cell or neuroendocrine cancer from a primary prostate ormetastatic biopsy confirmed by local laboratory.

2. Expression of NEPC markers (e.g., chromogranin or synaptophysin) in tumortissue by IHC confirmed by local laboratory

3. Progression of visceral metastases in the absence of PSA progression

4. Serum chromogranin A > 5x normal limit, or neuron-specific enolase > 2x normallimit with control for proton-pump inhibitors (PPI) drugs among concomitanttreatment

5. Prostate adenocarcinoma with molecular features of neuroendocrinedifferentiated cancer (e.g., 2 of the following 3: PTEN, TP53, or RB loss)

• PSMA and/or SSTR2 and/or GRPR PET-positive participants, with at least onemeasurable lesion per RECIST 1.1 with moderate target expression in at least one ofthe 3 PET/CT scans per BICR assessment

• Castrate level of serum/plasma testosterone (< 50 ng/dl, or < 1.7 nmol/L) forparticipants with adenocarcinoma component or stable testosterone level forparticipants with pure neuroendocrine carcinoma

• Recovered to ≤ Grade 2 from all clinically significant toxicities related to priortherapy

• Participant has adequate bone marrow and organ function (as assessed by centrallaboratory for eligibility)

• ECOG status =< 2

Key Exclusion criteria:

• Previous treatment with any of the following within 6 months prior to Screening:Strontium-89, Samarium-153, Rhenium-186, Rhenium-188, Radium-223, hemi-bodyirradiation

• Previous PSMA, SSTR2, or GRPR targeted radioligand therapy

• Other concurrent cytotoxic chemotherapy, immunotherapy, radioligand therapy orinvestigational therapy

• History of CNS metastases that are neurologically unstable, symptomatic, orreceiving corticosteroids for the purpose of maintaining neurologic integrity

• Symptomatic cord compression, or clinical or radiologic findings indicative ofimpending cord compression

• History or current diagnosis of ECG abnormalities indicating significant risk ofsafety for study participants

Other protocol-defined inclusion/exclusion criteria may apply.