NCT05356741 · Vir Biotechnology, Inc.
To Access the Safety and Effects of Intravenous Administration of VIR-5818 Alone and in Combination With Pembrolizumab in Adult Participants With Locally Advanced or Metastatic HER2-Expressing Cancers
What this study is about
This first-in-human (FIH) Phase 1 where both patients and doctors know the treatment given conducted at multiple hospitals gradually increasing doses and dose-expansion study is designed to evaluate the safety, how the drug moves through the body, and preliminary activity of VIR-5818 (Formerly AMX-818) as a single agent and in combination with pembrolizumab in participants with HER2+ tumors across multiple tumor types. The study will be conducted in four parts: * Part 1 (gradually increasing doses): Single-agent VIR-5818 * Part 2 (gradually increasing doses): VIR-5818 plus pembrolizumab * Part 3 (dose expansion): Single-agent VIR-5818 * Part 4 (dose expansion): VIR-5818 plus pembrolizumab The total length of the study, from screening of the first participant to the end of the study, is expected to be approximately 72 months.
View original scientific description
This first-in-human (FIH) Phase 1 open-label multicenter dose-escalation and dose-expansion study is designed to evaluate the safety, pharmacokinetics, and preliminary activity of VIR-5818 (Formerly AMX-818) as a single agent and in combination with pembrolizumab in participants with HER2+ tumors across multiple tumor types. The study will be conducted in four parts: * Part 1 (dose escalation): Single-agent VIR-5818 * Part 2 (dose escalation): VIR-5818 plus pembrolizumab * Part 3 (dose expansion): Single-agent VIR-5818 * Part 4 (dose expansion): VIR-5818 plus pembrolizumab The total length of the study, from screening of the first participant to the end of the study, is expected to be approximately 72 months.
Interventions
DRUG
VIR-5818
Administered as IV infusion
DRUG
pembrolizumab
Administered as IV infusion
Primary outcome measures
Incidence of dose-limiting toxicity - Part 1 and Part 2
Time frame: Up to approximately 21 days (Part 1) and 42 days (Part 2)
Number of participants with treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs)- Parts 1, 2, 3, and 4
Time frame: Up to approximately 55 months
Objective Response Rate (ORR) - Part 3 and Part 4
Time frame: Up to approximately 55 months
ORR defined as a Complete Response (CR) or Partial Response (PR) per Response Evaluation Criteria in Solid Tumors (RECIST) v.1.1.
Duration of Response (DOR) - Part 3 and Part 4
Time frame: Up to approximately 55 months
DOR defined as the time from the first occurrence of a documented objective response to the time of the first documented disease progression or death from any cause, whichever occurs first, per RECIST v.1.1.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Written informed consent by the participant (or legally acceptable representative if applicable)
- Life expectancy of at least 12 weeks
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
- Diseases under study, prior lines of therapy, and human epidermal growth factor receptor 2 (HER2) status, per local tests
Exclusion criteria
- Significant cardiopulmonary disease and recent cardiac events
- History of major organ autoimmune diseases
- Acute or chronic infections The above information is not intended to contain all considerations relevant to the potential participation in a clinical trial.
Where
- Duarte, California
Collaborators
Merck Sharp & Dohme LLC
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 19, 2026 · Source of record for eligibility and locations