Overview

The primary objectives of this study are to evaluate the safety and tolerability of xaluritamig administered as monotherapy or in combination with an oral Gonadotropin-releasing Hormone (GnRH) antagonist in the neoadjuvant setting followed by radical prostatectomy, and to evaluate the feasibility and safety of a radical prostatectomy following xaluritamig administered as monotherapy or in combination with an oral GnRH antagonist in the neoadjuvant setting.

Eligibility

Inclusion Criteria:

Participants are eligible to be included in the study only if all the following criteria apply:

• Participants planned to undergo radical prostatectomy.
• Histologically or cytologically confirmed adenocarcinoma of the prostate at initial biopsy, without neuroendocrine differentiation, signet cell, or small cell features. Intermediate- or high-risk localized prostate cancer, defined as:
  • Gleason score of 4+3 or higher AND initial PSA (iPSA) \>10 OR
  • Clinically advanced (cT3) on Magnetic Resonance Imaging (MRI) obtained within 3 months prior to screening AND/OR
  • Positive locoregional lymph nodes as detected by prostate-specific membrane antigen-positron emission tomography (PSMA-PET) scans OR ≤ 5 local lymph nodes on MRI can be enrolled.
• Participants must have undergone a PSMA-PET (CT or MRI) scan within 3 months prior to screening as part of the standard of care (SOC).
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1.

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

• Prior treatment for participant's prostate cancer.

  \- Exception: Participants intended for enrollment in cohort B may have received an oral GnRH antagonist up to 3 months prior to the start of screening.

• Any evidence of metastases outside of the surgical resection field identified by conventional imaging or PSMA-PET scans.
• Confirmed history or current autoimmune disease or other diseases resulting in permanent immunosuppression or requiring permanent immunosuppressive therapy.
• Participants with symptoms and/or clinical signs and/or radiographic signs that indicate an acute and/or uncontrolled active systemic infection within 7 days prior to the first dose of study treatment:

  \- Participant has known active infection requiring antibiotic treatment. Upon completion of antibiotics and resolution of symptoms, the participant may be considered eligible for the study from an infection standpoint.

• Recent history of arterial or venous thrombosis (eg, stroke, transient ischemic attack, pulmonary embolism, or deep vein thrombosis) within 6 and 3 months prior to the first dose of study treatment, respectively. Note: Participants with a history of venous thrombosis must be on stable anti-coagulation.
• Myocardial infarction and/or symptomatic congestive heart failure (New York Heart Association ≥ class II) within 12 months of first dose of xaluritamig with the exception of ischemia or non-ST segment elevation myocardial infarction controlled with stent placement more than 6 months prior to first dose of xaluritamig.
• Requirement for chronic systemic corticosteroid therapy unless stopped (with adequate tapering) within 7 days prior to dosing.
• Currently receiving treatment in another investigational device or drug study, or less than 4 weeks (since ending treatment on another investigational device or drug study\[ies\]). Other investigational procedures and participation in observational research studies while participating in this study are excluded with the exception of investigational scans.