A Phase 1, First-in-Human Study of the Safety, Pharmacokinetics, and Preliminary Efficacy of VIR-5500 (AMX-500) in Participants With Prostate Cancer
The study will be conducted in 4 parts and will commence with dose escalation of VIR-5500 as a monotherapy (Part 1), followed by combination escalation (Part 3a), monotherapy dose expansion (Part 2) and combination dose expansion (Part 4a). * Part 1 (Monotherapy Dose Escalation): Single-agent VIR-5500 dose escalation * Part 2 (Monotherapy Dose Expansion): Single-agent VIR-5500 dose expansion * Part 3 (Combination Dose Escalation): VIR-5500 plus another therapeutic agent dose escalation o Part 3a (Combination Dose Escalation): VIR-5500 in combination with an androgen receptor signaling inhibitor (ARSI) (enzalutamide or darolutamide) * Part 4 (Combination Dose Expansion): VIR-5500 plus another therapeutic agent dose expansion o Part 4a (Combination Dose Expansion): VIR-5500 in combination with an ARSI (enzalutamide or darolutamide)
⁃ Applicable to Parts 1 and 2
• Have metastatic disease, defined by ≥ 1 metastatic lesion that is present on baseline computed tomography (CT), magnetic resonance imaging (MRI), or bone scan imaging
• Have documented progressive mCRPC based on ≥ 1 of the criteria (per PCWG3)
• Have been treated with ≥ 1 second-generation androgen-signaling inhibitor, including abiraterone, 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 baseline CT, 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 lesions with no visceral involvement that are present on baseline CT, MRI, or bone scan imaging
• Have biochemical recurrent prostate cancer