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 screening by computed tomography (CT) or magnetic resonance imaging (MRI) and 99m\^Tc bone scan as determined by the investigator
* Participants must receive ongoing androgen deprivation therapy (ADT) with a gonadotropin releasing hormone (GnRH) analog throughout the treatment or have had prior bilateral orchiectomy, and have serum testosterone less than or equal to (\<=) 50 nanogram per deciliter (ng/dL) (\<= 1.73 nanomoles per Liter \[nmol/L\]) at screening
* Have progressed by PSA or CT/MRI or 99m\^Tc bone scan on at least 1 novel androgen receptor pathway inhibition (ARPI) but no more than 2 different ARPI for any stage of disease. Must have discontinued 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 or somatic) 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)
* Received cytotoxic chemotherapy for prostate cancer in any setting
* Received prior treatment with human kallikrein 2 (KLK-2) directed therapies