A Study of Pasritamig With Docetaxel Versus Docetaxel in Participants With Metastatic Castration-Resistant Prostate Cancer

Inclusion criteria:

• Have histologically confirmed adenocarcinoma of the prostate

• Have disease that is metastatic at the time of the screening as determined by theinvestigator

• Participants must receive ongoing androgen deprivation therapy (ADT) with agonadotropin releasing hormone (GnRH) analog throughout the treatment or have hadprior bilateral orchiectomy, and have serum testosterone less than or equal to (<=) 50 nanogram per milliliter (ng/dL) (<= 1.73 nanomoles per Liter [nmol/L]) atscreening

• Have progressed on at least 1 novel androgen receptor pathway inhibition (ARPI) butreceived no more than 2 different ARPI for any stage of disease. Must havediscontinued ARPI before randomization into the study

• Have an eastern cooperative oncology group (ECOG) performance status of 0 to 1

Exclusion criteria:

• Known history of either brain or leptomeningeal prostate cancer metastases

• Participants with known breast cancer gene 1/2 (BRCA 1/2) mutations (germline orsomatic) who have not received treatment with a poly (ADP-ribose) polymerase (PARP)inhibitor, unless not available or contraindicated

• Prior or concurrent second malignancy (other than the disease under study) becausethe natural history or treatment could interfere with study endpoints

• Received cytotoxic chemotherapy for prostate cancer in any setting

• Received prior treatment with human kallikrein 2 (KLK-2) directed therapies