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RecruitingLast updated: 24 December 2025

AMG 20230239: Immunotherapy plus hormone therapy, compared to Investigator's choice of standard treatment, for people with metastatic castration-resistant prostate cancer (mCRPC) who have not had prior chemotherapyA Phase 3, Open-label, Multicenter, Randomized Study of Xaluritamig Plus Abiraterone Versus Investigator's Choice in Participants With Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer

Trial purpose

Medical clipboardCancer treatment

Tumor type

Urinary System Cancers Genitourinary

Age

People18+

Trial acronym

AMG 20230239

Clinical summary

Summary

The primary objective of this study is to compare overall survival in people receiving xaluritamig immunotherapy plus abiraterone hormone therapy against Investigator's choice of treatment (either docetaxel chemotherapy, cabazitaxel chemotherapy or abiraterone hormone therapy). 

You may be eligible if you have metastatic castration-resistant prostate cancer (mCRPC), have progressive disease, and have had a prior orchiectomy and/or ongoing androgen-deprivation therapy. Prior disease progression on 1, and only 1, androgen receptor pathway inhibitor (ARPI) is required. 

Eligible participants will be randomly allocated (by chance) to one of two treatment groups:

In the Experimental Group, participants will receive xaluritamig immunotherapy intravenously (via IV) plus abiraterone acetate hormone therapy orally.

In the Active Comparator Group, participants will receive Investigator's choice of either:

  • Abiraterone acetate hormone therapy orally,once daily
  • Docetaxel chemotherapy via IV every 3 weeks
  • Cabazitaxel via IV every 3 weeks

Conditions

This trial is treating people with metastatic castration-resistant prostate cancer

Eligibility

Inclusion

  • Participant has provided informed consent before initiation of any study-specific activities/procedures.
  • Age ≥ 18 years (or ≥ legal age within the country if it is older than 18 years) at the time of signing the informed consent.
  • Participant must have histological, pathological, and/or cytological confirmation of adenocarcinoma of the prostate. Mixed histologies (eg, adenocarcinoma with neuroendocrine component) are not permitted.
  • Metastatic castration-resistant prostate cancer (mCRPC) with ≥ 1 metastatic lesion that is present on baseline computed tomography (CT), magnetic resonance imaging (MRI), or bone scan imaging obtained within 28 days before enrollment.

  • Evidence of progressive disease (PD), defined as 1 or more PCWG3-modified RECIST 1.1 criteria:

    • Serum PSA progression is defined as 2 consecutive increases in PSA over a previous reference value measured at least 1 week prior. The minimum start value is 2.0 ng/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 all target lesions based on the smallest SOD since treatment started or the appearance of 1 or more new lesions or unequivocal progression of existing non-target lesions.
    • Progression of bone disease defined by the appearance of at least 2 new bone lesions(s) by bone scan (as per the 2+2 PCWG3-modified RECIST 1.1 criteria).
  • Participants must have had prior orchiectomy and/or ongoing androgen-deprivation therapy (ADT) and a castrate level of serum testosterone (< 50 ng/dL or < 1.7 nmol/L).
  • Prior disease progression on 1, and only 1, androgen receptor pathway inhibitor (ARPI) (either enzalutamide, apalutamide, or darolutamide) is required.
  • Participants intended to receive cabazitaxel must have previously received ≤ 6 cycles of docetaxel in the metastatic hormone-sensitive prostate cancer (mHSPC) setting.
  • Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1.
  • Adequate organ function.

Exclusion

Disease Related:

  • Participants with a history of central nervous system (CNS) metastases.
  • Unresolved toxicities from prior antitumor therapy not having resolved to CTCAE version 5.0 grade 1 or baseline, with the exception of alopecia or toxicities that are stable and well-controlled AND there is an agreement to allow inclusion by both the investigator and the sponsor.

Prior/Concomitant Therapy:

  • Prior six transmembrane epithelial antigen of the prostate 1 (STEAP1)-targeted therapy.
  • Prior disease progression on or intolerance to abiraterone.
  • Prior treatment with any chemotherapy regimen in the mCRPC setting and/or > 6 cycles of docetaxel treatment in the mHSPC setting.
  • Any anticancer therapy, immunotherapy, or investigational agent within 4 weeks before first dose of study treatment, not including androgen suppression therapy (eg, luteinizing hormone-releasing hormone/gonadotropin releasing hormone [LHRH/GnRH] analogue [agonist/antagonist]).
  • Prior Prostate-Specific Membrane Antigen (PSMA) radioligand therapy (RLT) within 3 months of first dose of study treatment. Participants who received < 2 cycles of PSMA RLT within 6 weeks of first dose of study treatment are also excluded.
  • Prior radionuclide therapy (radium-223) within 2 months of first dose of study treatment.
  • Prior palliative radiotherapy within 2 weeks before first dose of study treatment. Participants must have recovered from all radiation-related toxicities.
  • Concurrent cytotoxic chemotherapy, ARPI, immunotherapy, RLT, poly adenosine diphosphate ribose polymerase (PARP) inhibitor, biological therapy, investigational therapy.
  • Treatment with live and live-attenuated vaccines within 4 weeks before the first dose of study treatment.

Inclusion

  • Your cancer has spread to other parts of the body (metastatic) or has grown into nearby parts of the body (locally advanced).
  • You have had treatment but your cancer has gotten worse or has not responded to the treatment you have been given.
  • You have had a certain type of treatment or surgical procedure.

Exclusion

  • You have certain types of non-cancer medical conditions.
  • You have had certain treatments, surgical procedures or drugs.
Message

Clinical trials have complex eligibility criteria, and other criteria may apply for this trial. Ask your doctor about whether this trial could be right for you.

Participating hospitals

Recruiting hospitals

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Trial Identifiers

Information on this page is partially produced from ClinicalTrials.gov *. View further details about this trial on the registry via the links below:

Trial sponsor

Amgen

Scientific Title

A Phase 3, Open-label, Multicenter, Randomized Study of Xaluritamig Plus Abiraterone Versus Investigator's Choice in Participants With Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer

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