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 Part 3a (Combination Dose Escalation): VIR-5500 in combination with an androgen receptor signaling inhibitor (ARSI) * Part 4 (Combination Dose Expansion): VIR-5500 plus another therapeutic agent dose expansion Part 4a (Combination Dose Expansion): VIR-5500 in combination with an androgen receptor signaling inhibitor (ARSI)
∙ 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)
‣ PSA level ≥ 1 ng/mL that has increased on ≥ 2 successive occasions ≥ 1 week apart
⁃ Nodal or visceral progression as defined by RECIST v1.1 with PCWG3 modifications
⁃ Appearance of ≥ 2 new lesions in bone scan
• 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, 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):
‣ PSA level ≥ 1 ng/mL that has increased on ≥ 2 successive occasions ≥ 1 week apart
⁃ Nodal or visceral progression as defined by RECIST v1.1 with PCWG3 modifications
⁃ Appearance of ≥2 new lesions in bone scan
• Participants with metastatic hormone sensitive prostate cancer (mHSPC) or with biochemical recurrent prostate cancer (BRPC) may also participate in select cohorts of this clinical trial.