437 Participants NeededMy employer runs this trial

VIR-5500 for Prostate Cancer

Recruiting at 14 trial locations
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Overseen ByTrial Transparency email recommended (Toll free for US & Canada)
Age: 18+
Sex: Male
Trial Phase: Phase 1
Sponsor: Astellas Pharma Global Development, Inc.
Must be taking: Androgen receptor inhibitors
No Placebo GroupAll trial participants will receive the active study treatment (no placebo)

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to test the safety and effectiveness of a new treatment called VIR-5500 for prostate cancer. Researchers will study VIR-5500 both alone and in combination with other drugs that block cancer growth. It targets individuals with advanced prostate cancer that has spread and continued to progress. Participants should have previously tried specific prostate cancer treatments that proved unsuitable or ineffective. As a Phase 1 trial, the research focuses on understanding how the treatment works in people, offering participants the opportunity to be among the first to receive this new treatment.

Do I need to stop my current medications for the trial?

The trial information does not specify if you need to stop taking your current medications. However, since the trial involves combination therapy with androgen receptor signaling inhibitors, you might need to continue those if you're already on them. It's best to discuss your specific medications with the trial team.

Is there any evidence suggesting that VIR-5500 is likely to be safe for humans?

Research has shown that VIR-5500 is generally safe. Previous studies found it well-tolerated by patients with advanced prostate cancer, with most participants not experiencing serious side effects. The treatment specifically targets the tumor, potentially reducing unwanted effects on healthy body parts. When combined with an androgen receptor signaling inhibitor (ARSI), early results also suggest that VIR-5500 remains safe. These findings offer reassurance about VIR-5500's safety for those considering participation in clinical trials.12345

Why do researchers think this study treatment might be promising for prostate cancer?

Most treatments for prostate cancer, like hormone therapies and chemotherapy, work by either lowering testosterone levels or targeting cancer cell growth. But VIR-5500 works differently, focusing on a novel mechanism that may target cancer cells more precisely. Researchers are excited about VIR-5500 because it could offer a more targeted approach, potentially leading to fewer side effects and better outcomes for patients with metastatic castration-resistant prostate cancer (mCRPC). Additionally, the combination of VIR-5500 with an androgen receptor signaling inhibitor (ARSI) could enhance its effectiveness, offering a new hope for patients who have limited options.

What evidence suggests that VIR-5500 might be an effective treatment for prostate cancer?

Research has shown that VIR-5500 may help treat advanced prostate cancer that no longer responds to standard hormone therapy. An early study with 58 patients, who had already tried many treatments, found that 58% experienced a significant drop in their PSA levels, which are used to monitor prostate cancer. Importantly, no severe side effects emerged that would prevent dose escalation, indicating potential safety. In this trial, participants will receive VIR-5500 either as a monotherapy or in combination with other prostate cancer drugs like enzalutamide or darolutamide. While more information is still being gathered, these early results suggest VIR-5500 could be a promising treatment option for prostate cancer.12678

Who Is on the Research Team?

CS

Clinical Sciences & Operations

Principal Investigator

Sanofi

Are You a Good Fit for This Trial?

This trial is for people with advanced prostate cancer that has spread (metastatic) and keeps growing despite treatment. Participants must have tried at least one newer hormone therapy and chemotherapy, and be unsuitable for standard treatments. People with certain infections, brain involvement, or specific rare tumor types cannot join.

Inclusion Criteria

I have metastatic prostate cancer that has progressed after hormone and chemo treatments.
I have prostate cancer that has spread, or my PSA levels are rising after treatment.
I have received standard PSMA-targeted radioligand therapy for my cancer.

Exclusion Criteria

I have another medical or inflammatory condition that could increase my risk of side effects from VIR-5500.
I currently have an acute or chronic infection.
My tumors are close to important organs.
See 2 more

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Monotherapy Dose Escalation

Single-agent VIR-5500 dose escalation in patients with mCRPC over a 21-day cycle

21 days per cycle

Monotherapy Dose Expansion

Single-agent VIR-5500 dose expansion in patients with mCRPC over a 21-day cycle

21 days per cycle

Combination Dose Escalation

VIR-5500 in combination with an ARSI (enzalutamide or darolutamide) for dose escalation

21 days per cycle

Combination Dose Expansion

VIR-5500 in combination with an ARSI (enzalutamide or darolutamide) for dose expansion

21 days per cycle

Follow-up

Participants are monitored for safety and effectiveness after treatment

up to 48 months

What Are the Treatments Tested in This Trial?

Interventions

  • VIR-5500

Trial Overview

The study tests a new drug called VIR-5500 alone and in combination with enzalutamide or darolutamide (both are hormone therapies). The trial will first find the best dose of VIR-5500 by itself, then test it together with other drugs to see how safe and effective these combinations are.

How Is the Trial Designed?

4

Treatment groups

Experimental Treatment

Group I: Part 4a: VIR-5500 in combination with an ARSI for Dose ExpansionExperimental Treatment2 Interventions
Group II: Part 3a: VIR-5500 in combination with an ARSI for Dose EscalationExperimental Treatment2 Interventions
Group III: Part 2: VIR-5500 Monotherapy Dose ExpansionExperimental Treatment1 Intervention
Group IV: Part 1: VIR-5500 Monotherapy Dose EscalationExperimental Treatment1 Intervention

Find a Clinic Near You

Who Is Running the Clinical Trial?

Astellas Pharma Global Development, Inc.

Lead Sponsor

Trials
204
Recruited
123,000+

Tadaaki Taniguchi

Astellas Pharma Global Development, Inc.

Chief Medical Officer

M.D., Ph.D.

Naoki Okamura profile image

Naoki Okamura

Astellas Pharma Global Development, Inc.

Chief Executive Officer

Not available

Amunix, a Sanofi Company

Lead Sponsor

Trials
2
Recruited
860+

Vir Biotechnology, Inc.

Industry Sponsor

Trials
30
Recruited
13,300+

Citations

Preliminary phase 1 dose escalation results of VIR-5500 ...

Results: As of 23 September 2025, 51 heavily pretreated mCRPC pts (~95% post-taxane) received ≥ 1 dose of VIR-5500. No dose limiting toxicities ...

Vir Biotechnology Announces First Patient Dosed in Phase ...

The Phase 1 trial is measuring the safety and efficacy of VIR-5500 monotherapy in late-line mCRPC, and of VIR-5500 in combination with an ...

Preliminary Phase 1 Dose Escalation Results of VIR-5500 ...

As of January 9, 2026, 58 heavily pretreated mCRPC participants (94.8% post-taxane) received ≥ 1 dose of VIR-5500. These were heavily pre- ...

VIR-5500 enters expansion cohorts in phase 1 trial for ...

The trial is assessing the safety and efficacy of VIR-5500 monotherapy in late-line metastatic castration-resistant prostate cancer (mCRPC) and ...

Preliminary phase 1 dose escalation results of VIR-5500 ...

Results: As of 23 September 2025, 51 heavily pretreated mCRPC pts (~95% post-taxane) received ≥ 1 dose of VIR-5500. No dose limiting toxicities (pre-defined ...

Study Details | NCT05997615 | Safety, Pharmacokinetics, ...

Also called a data safety and monitoring board, or DSMB. ... Safety, Pharmacokinetics, and Preliminary Efficacy of VIR-5500 (AMX-500) in Prostate Cancer.

Vir Biotechnology Announces Encouraging Safety and ...

Vir Biotechnology's Phase 1 data on dual-masked TCEs, VIR-5818 and VIR-5500, show promising safety and efficacy in solid tumors and mCRPC ...

Clinical Trial Details

Safety, Pharmacokinetics, and Preliminary Efficacy of VIR-5500 (AMX-500) in Prostate Cancer. Complete Title: A Phase 1, First-in-Human Study ...