OncoMatch/Clinical Trials/NCT05997615

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

Official title: A Phase 1, First-in-Human Study of the Safety, Pharmacokinetics, and Preliminary Efficacy of VIR-5500 (AMX-500) in Participants With Prostate Cancer

Is NCT05997615 recruiting? Yes, currently enrolling (Oct 2026). This Phase 1 trial studies multiple treatments including VIR-5500 and Androgen receptor signaling inhibitor (ARSI) for hormone-refractory prostate cancer.

Treatment: VIR-5500 · Androgen receptor signaling inhibitor (ARSI) · Docetaxel — There are many treatment options for men with various stages of prostate cancer. Some treatments work well for a while but can cause medical problems in some men. Also, the cancer may come back after treatment. This is an early development study of VIR-5500 in men with prostate cancer. In this study, VIR-5500 will be given to people for the first time. VIR-5500 will either be given by itself or given together with one or more standard cancer treatments: enzalutamide, darolutamide and docetaxel. Some other cancer treatments may also be given with VIR-5500 during this study, depending on results from other ongoing studies. Early development studies are mostly about safety, but also to find the most suitable dose. Other aims are to check if VIR-5500 shows signs of reducing tumor growth and to learn how the body processes VIR-5500. This will be done both for VIR-5500 given by itself and given together with the other cancer treatments. The main aim(s) of the study are to check the safety of different doses of VIR-5500 when given by itself and given together with the standard cancer treatments, and how well it is tolerated; to find a suitable dose of VIR-5500 when given by itself and given together with the standard cancer treatments; to check the safety of VIR-5500 when given by itself to people in China and Japan; and to check how well VIR-5500 controls tumors when given by itself and given together with the standard cancer treatments. Adult men with certain types of advanced prostate cancer can take part. Their cancer has spread to other parts of the body (metastatic). The different types of cancer in this study are: Metastatic hormone-sensitive prostate cancer (mHSPC). Prostate cancer that needs testosterone to grow; Metastatic castration-resistant prostate cancer (mCRPC). Prostate cancer that continues to grow even when testosterone levels are low; and High-risk biochemical recurrent prostate cancer (high-risk BRPC). Biochemical recurrence is a rise in PSA levels after treatment for prostate cancer. Men whose PSA levels double in less than 1 year are considered high risk of the cancer coming back and quickly getting worse. In this study, VIR-5500 will be given to people for the first time. VIR-5500 will either be given itself or given together with at least one of the standard cancer treatments: enzalutamide, darolutamide, and docetaxel. The standard cancer treatment given will depend on which part of the study the men are in, and what type of prostate cancer they have. Other cancer treatments may be given, depending on results from other ongoing studies. The study will have 4 parts. In Part 1, different small groups of men with Metastatic castration-resistant prostate cancer (mCRPC) will receive lower to higher doses of VIR-5500 given by itself. Any medical problems will be recorded for each dose. This is to find out suitable doses to use in Part 2 of the study. In Part 2, other small groups of men with mCRPC will receive the suitable doses of VIR-5500 worked out from Part 1. These men will have previously received specific cancer treatments before starting this study. In Part 3, other different small groups of men with metastatic hormone-sensitive prostate cancer (mHSPC), mCRPC or high-risk BRPC will receive lower to higher doses of VIR-5500 given by itself or given with the other standard cancer treatments. They will be given VIR-5500 with enzalutamide or darolutamide, VIR-5500 with docetaxel, VIR-5500 with docetaxel and enzalutamide, or VIR- 5500 with docetaxel and darolutamide. Any medical problems will be recorded for each dose. This is to find out suitable doses to use in Part 4 of the study. In Part 4, other small groups of men with mHSPC, mCRPC or high-risk biochemical recurrent prostate cancer (BRPC) will receive the suitable doses of VIR-5500 given together with the standard cancer treatments, worked out in Part 3. They will be given VIR-5500 with enzalutamide, VIR-5500 with darolutamide, VIR-5500 with docetaxel and enzalutamide, or VIR-5500 with docetaxel and darolutamide. The standard cancer treatment given will depend on their previous treatment before joining the study and the type of prostate cancer they have.