Phase 3 Study of Xaluritamig vs Cabazitaxel or Second Androgen Receptor-Directed Therapy in Participants With Progressive Metastatic Castration-Resistant Prostate Cancer (XALute)

Inclusion Criteria:

• Participant has provided informed consent prior to initiation of any study-specificactivities/procedures.

• Age ≥ 18 years (or ≥ legal age within the country if it is older than 18 years) atthe time of signing the informed consent.

• Participant must have histological, pathological, and/or cytological confirmation ofadenocarcinoma of the prostate. Mixed histologies (eg, adenocarcinoma withneuroendocrine component) are not permitted.

• mCRPC with ≥ 1 metastatic lesion that is present on baseline computed tomography (CT), magnetic resonance imaging (MRI), or bone scan imaging obtained within 28 daysprior to enrollment.

• Evidence of progressive disease, defined as 1 or more PCWG3 criteria:

• Serum PSA progression defined as 2 consecutive increases in PSA over a previousreference value measured at least 1 week prior. The minimal start value is 2.0ng/mL.

• Soft-tissue progression defined as an increase ≥ 20% in the sum of the diameter (SOD) (short axis for nodal lesions and long axis for non-nodal lesions) of alltarget lesions based on the smallest SOD since treatment started or theappearance of one or more new lesions or unequivocal progression of existingnon-target lesions.

• Progression of bone disease: defined by the appearance of at least 2 new bonelesion(s) by bone scan (as per the 2+2 PCWG3 criteria).

• Participants must have had a prior orchiectomy and/or ongoing androgen-deprivationtherapy and a castrate level of serum testosterone (< 50 ng/dL or < 1.7 nmol/L).

• Prior progression on at least one ARDT (enzalutamide, abiraterone, apalutamide,darolutamide).

• Prior treatment with only one taxane therapy in the mCRPC setting. Note: Priortreatment with docetaxel in the metastatic hormone-sensitive prostate cancer (mHSPC)setting is permitted; however, participants must have also received one, and onlyone, taxane therapy in the mCRPC setting.

• Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 or 1.

• Adequate organ function.

• Life expectancy of ≥ 12 weeks per the treating physician's assessment.

Key Exclusion Criteria:

Prior & Concomitant Therapy:

• Prior six transmembrane epithelial antigen of the prostate 1 (STEAP1)-targetedtherapy.

• Any anticancer therapy, immunotherapy, or investigational agent within 4 weeks priorto the first dose of study treatment, not including androgen receptor pathwayinhibitors (ARPIs) (abiraterone, enzalutamide, darolutamide, apalutamide): minimumwashout of 2 weeks prior to the first dose of study treatment and androgensuppression therapy (eg, luteinizing hormone-releasinghormone/gonadotropin-releasing hormone [LHRH/GnRH] analogue [agonist/antagonist]).

• Prior Prostate-Specific Membrane Antigen (PSMA) radioligand therapy (RLT) within 3months of the first dose of study treatment unless participants received < 2 cyclesof therapy.

• Prior palliative radiotherapy within 2 weeks of first dose of study treatment.Participants must have recovered from all radiation-related toxicities.

• Concurrent cytotoxic chemotherapy, ARDT, immunotherapy, radioligand therapy, PARPinhibitor, biological therapy, investigational therapy. Note: Prior treatment with aPARP inhibitor is permitted as long as not within 4 weeks before first dose of studytreatment.

• Prior radionuclide therapy (Radium-223) within 2 months of first dose of studytreatment.

• Treatment with live and live-attenuated vaccines within 4 weeks before the firstdose of study treatment.

Disease Related:

• Participants with a history of central nervous system (CNS) metastasis. Note:Participants with treated, asymptomatic, and clinically stable dural metastases areeligible.

• Unresolved toxicities from prior anti-tumor therapy not having resolved to CTCAEversion 5.0 events grade above 1 or baseline, with the exception of alopecia ortoxicities that are stable and well controlled AND there is an agreement to allowinclusion by both the investigator and the sponsor.