Safety, Pharmacokinetics, and Preliminary Efficacy of VIR-5500 (AMX-500) in Prostate Cancer

Inclusion Criteria:

Applicable to Parts 1 and 2

• Have metastatic disease, defined by ≥ 1 metastatic lesion that is present onbaseline computed tomography (CT), magnetic resonance imaging (MRI), or bone scanimaging

• Have documented progressive mCRPC based on ≥ 1 of the criteria (per PCWG3)

• Have been treated with ≥ 1 second-generation androgen-signaling inhibitor, includingabiraterone, apalutamide, darolutamide, and/or enzalutamide

• Have been treated with ≥ 1 prior taxane regimens (e.g., docetaxel, cabazitaxel)

• Are deemed unsuitable for standard of care

Applicable to Part 2 Cohort 1

• Must have received standard-of-care radioligand-based therapies, including PSMA-targeted radiopharmaceutical therapy, such as 177Lu-PSMA-617

Applicable to Part 3a and Part 4a

• Have metastatic CRPC, defined by ≥ 1 metastatic lesion that is present on baselineCT, MRI, or bone scan imaging that has documented progressive disease (PD) based on ≥ 1 of the following criteria (per PCWG3)

• Have metastatic HSPC, defined by at least 1 and no more than 5 metastatic lesionswith no visceral involvement that are present on baseline CT, MRI, or bone scanimaging

• Have biochemical recurrent prostate cancer

Exclusion Criteria:

• Presence of dominant histopathological features representative of sarcomatoid,spindle cell, or neuroendocrine small cell components

• Has acute or chronic infections

• Has a concomitant medical or inflammatory condition that may increase the risk oftoxicity to VIR-5500, per the Investigator

• Has lesions in proximity of vital organs

• Has known active CNS metastases and/or carcinomatous meningitis The aboveinformation is not intended to contain all considerations relevant to a patient'spotential participation in a clinical trial.