Head and Neck Squamous Cell CarcinomaPhase 1NCT05585034
Phase 1, First-in-human, Dose-finding and Expansion Study to Evaluate XmAb®808 in Combination With Pembrolizumab in Advanced Solid Tumors
A Phase 1 study testing XmAb®808 and Keytruda® (pembrolizumab) in people with Head and Neck Squamous Cell Carcinoma and Melanoma Excluding Uveal Melanoma, run by Xencor, Inc. at 12 sites in United States.
Trial summary
The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of intravenous (IV) administration of XmAb808 in combination with pembrolizumab in subjects with selected advanced solid tumors and to identify the minimum safe and biologically effective/recommended dose (RD) and schedule for… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Head and Neck Squamous Cell Carcinoma, Melanoma Excluding Uveal Melanoma, Non-small Cell Lung Cancer, Squamous or Non-squamous
- What is being tested?
- XmAb®808 and Keytruda® (pembrolizumab)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 12 sitesUnited States
- Study dates
- 14 Dec 2022to 20 May 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Part A: Histologically confirmed advanced/metastatic castration-resistant prostate adenocarcinoma, epithelial ovarian cancer, head and neck squamous cell carcinoma, non-small cell lung cancer, urothelial carcinoma, melanoma, renal cell carcinoma, triple-negative breast cancer, or colorectal cancer that has progressed on standard therapies
- Part B: Histologically confirmed advanced/metastatic castration-resistant prostate cancer that is PD1-naïve; head and neck squamous cell carcinoma that is PD1-naïve or has progressed on prior PD1 therapy; or melanoma that is PD1-naïve or has progressed on prior PD1 therapy
- Measurable disease by RECIST 1.1; subjects with prostate cancer who have evaluable disease according to PCWG3 criteria may enroll
- Life expectancy > 3 months
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Who cannot join
- Subjects currently receiving other anticancer therapies
- Any prior treatment with an investigational agent targeting CD28
- History of a life-threatening adverse event related to prior immunotherapy
- Known active central nervous system involvement by malignant disease. Subjects with previously treated brain metastases may participate provided they are radiologically and clinically stable
Trial locations and contacts
12 sites in 1 country.
12 sites in 1 country
United States12 sites
Winship Cancer Institute, Emory University
Atlanta, Georgia, 30322
Northwestern Memorial Hospital
Chicago, Illinois, 60611
University of Cincinnati Medical Center
Cincinnati, Ohio, 45219
Sarah Cannon Research Institute at HealthONE
Denver, Colorado, 80218
The University of Texas MD Anderson Cancer Center
Houston, Texas, 77030
UCLA Hematology/Oncology
Los Angeles, California, 90095
Froedtert Hospital & The Medical College of Wisconsin
Milwaukee, Wisconsin, 53226
Tennessee Oncology
Nashville, Tennessee, 37203
Columbia University Irvine Medical Center
New York, New York, 10032
UPMC Hillman Cancer Center
Pittsburgh, Pennsylvania, 15213
Huntsman Cancer Institute, University of Utah
Salt Lake City, Utah, 84112
Florida Cancer Specialists
Sarasota, Florida, 34232
About this study
Official title: A Phase 1, First-in-Human, Dose-Finding and Expansion Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Activity of XmAb®808 in Combination With Pembrolizumab in Selected Advanced Solid Tumors
The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of intravenous (IV) administration of XmAb808 in combination with pembrolizumab in subjects with selected advanced solid tumors and to identify the minimum safe and biologically effective/recommended dose (RD) and schedule for XmAb808.
Read the detailed description
This is a Phase 1, open-label, first-in-human (FIH), multiple-dose, dose escalation study with cohort expansion at the RD, designed to evaluate the safety and tolerability of XmAb808 in combination with pembrolizumab. This study will be conducted in 2 parts: Part A (dose escalation) and Part B (cohort expansion).
- Conditions
- Head and Neck Squamous Cell Carcinoma, Melanoma Excluding Uveal Melanoma, Non-small Cell Lung Cancer, Squamous or Non-squamous, Urothelial Carcinoma, Renal Cell Carcinoma, Clear Cell, Castration-resistant Prostate Cancer
- Being tested
- XmAb®808, Keytruda® (pembrolizumab)
- Medical subject headings
- Squamous Cell Carcinoma of Head and Neck, Carcinoma, Non-Small-Cell Lung, Carcinoma, Transitional Cell, Carcinoma, Renal Cell, Carcinoma, Ovarian Epithelial, Triple Negative Breast Neoplasms, Colorectal Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
XmAb®808Biological
Monoclonal bispecific antibody
Keytruda® (pembrolizumab)Biological
Monoclonal antibody
| Study group | Role | What they receive |
|---|---|---|
| Dose Escalation and Expansion XmAb®808 administered in combination with pembrolizumab | Experimental | XmAb®808 in combination with pembrolizumab Receives: Biological: XmAb®808; Biological: Keytruda® (pembrolizumab) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of treatment-emergent adverse events (TEAEs)
Safety and tolerability as assessed by incidence of TEAEs, including clinically significant changes in safety laboratory tests and clinical findings
Measured: Up to 5 years
Incidence of dose-limiting toxicities (DLTs)
Safety and tolerability as assessed by incidence of DLTs and all available data which will be used to determine the optimal dose regimen
Measured: 49 days
Secondary outcomes (5)
Measurement of Cmax
Peak plasma concentration (Cmax)
Measured: Through study completion, Up to 5 years
Measurement of AUCtau
Area under the plasma concentration versus time curve (AUCtau)
Measured: Through study completion, Up to 5 years
Objective Response Rate
Objective response rate by RECIST 1.1 assessment of CT/MRI imaging, as modified by PCWG3 for participants with prostate cancer
Measured: Through study completion, Up to 5 years
Progression-free Survival
Progression-free survival by RECIST 1.1 assessment of CT/MRI imaging, as modified by PCWG3 for participants with prostate cancer
Measured: Through study completion, Up to 5 years
Duration of Response
Duration of Response by RECIST 1.1 assessment of CT/MRI imaging, as modified by PCWG3 for participants with prostate cancer
Measured: Through study completion, Up to 5 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Oct 2022
- Study start14 Dec 2022
- Primary completion20 May 2025
- Study completion20 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Head and Neck Squamous Cell CarcinomaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Xencor, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Mira Kistler, MD, Study director, Xencor, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05585034
- Sponsor's protocol ID
- XmAb808-01
- Status last verified
- Aug 2025
- First submitted
- 11 Oct 2022
- Last updated
- 7 Aug 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1, First-in-Human, Dose-Finding and Expansion Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Activity of XmAb®808 in Combination With Pembrolizumab in Selected Advanced Solid Tumors
- ClinicalTrials.gov ID
- NCT05585034
- Acronym / sponsor ID
- XmAb808-01
- Conditions
- Head and Neck Squamous Cell Carcinoma, Melanoma Excluding Uveal Melanoma, Non-small Cell Lung Cancer, Squamous or Non-squamous, Urothelial Carcinoma, Renal Cell Carcinoma, Clear Cell, Castration-resistant Prostate Cancer
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Xencor, Inc.Industry (pharma, biotech, devices)
- Study start
- 14 Dec 2022 (actual)
- Primary completion
- 20 May 2025 (actual)
- Study completion
- 20 May 2025 (actual)
- First posted
- 18 Oct 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics of intravenous (IV) administration of XmAb808 in combination with pembrolizumab in subjects with selected advanced solid tumors and to identify the minimum safe and biologically effective/recommended dose (RD) and schedule for XmAb808.
Detailed description
This is a Phase 1, open-label, first-in-human (FIH), multiple-dose, dose escalation study with cohort expansion at the RD, designed to evaluate the safety and tolerability of XmAb808 in combination with pembrolizumab. This study will be conducted in 2 parts: Part A (dose escalation) and Part B (cohort expansion).
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Dose Escalation and Expansion XmAb®808 administered in combination with pembrolizumab | Experimental | Biological: XmAb®808, Biological: Keytruda® (pembrolizumab)XmAb®808 in combination with pembrolizumab |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Part A: Histologically confirmed advanced/metastatic castration-resistant prostate adenocarcinoma, epithelial ovarian cancer, head and neck squamous cell carcinoma, non-small cell lung cancer, urothelial carcinoma, melanoma, renal cell carcinoma, triple-negative breast cancer, or colorectal cancer that has progressed on standard therapies
- Part B: Histologically confirmed advanced/metastatic castration-resistant prostate cancer that is PD1-naïve; head and neck squamous cell carcinoma that is PD1-naïve or has progressed on prior PD1 therapy; or melanoma that is PD1-naïve or has progressed on prior PD1 therapy
- Measurable disease by RECIST 1.1; subjects with prostate cancer who have evaluable disease according to PCWG3 criteria may enroll
- Life expectancy > 3 months
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Key exclusion criteria (4 listed)
- Subjects currently receiving other anticancer therapies
- Any prior treatment with an investigational agent targeting CD28
- History of a life-threatening adverse event related to prior immunotherapy
- Known active central nervous system involvement by malignant disease. Subjects with previously treated brain metastases may participate provided they are radiologically and clinically stable
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| XmAb®808Monoclonal bispecific antibody | Biological | Dose Escalation and Expansion XmAb®808 administered in combination with pembrolizumab |
| Keytruda® (pembrolizumab)Monoclonal antibody | Biological | Dose Escalation and Expansion XmAb®808 administered in combination with pembrolizumab |
Primary outcome
Incidence of treatment-emergent adverse events (TEAEs)
Time frame: Up to 5 years
Safety and tolerability as assessed by incidence of TEAEs, including clinically significant changes in safety laboratory tests and clinical findings
Incidence of dose-limiting toxicities (DLTs)
Time frame: 49 days
Safety and tolerability as assessed by incidence of DLTs and all available data which will be used to determine the optimal dose regimen
5 secondary outcomes
Measurement of Cmax
Time frame: Through study completion, Up to 5 years
Measurement of AUCtau
Time frame: Through study completion, Up to 5 years
Objective Response Rate
Time frame: Through study completion, Up to 5 years
Progression-free Survival
Time frame: Through study completion, Up to 5 years
Duration of Response
Time frame: Through study completion, Up to 5 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mira Kistler, MD study director
Xencor, Inc.
12 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing XmAb®808 and Keytruda® (pembrolizumab) in people with Head and Neck Squamous Cell Carcinoma and Melanoma Excluding Uveal Melanoma, run by Xencor, Inc. at 12 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 12 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of treatment-emergent adverse events (TEAEs) (time frame: Up to 5 years). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Aug 2025; AzTrials last refreshed its copy on 26 Oct 2026.