Advanced CancerPhase 1ARC-25NCT05891171
Study of AB598 Monotherapy and Combination Therapy in Participants With Advanced Cancers
A Phase 1 study testing AB598, Zimberelimab and Fluorouracil in people with Advanced Cancer and Advanced Malignancies, run by Arcus Biosciences, Inc. at 19 sites in 3 countries.
Trial summary
The primary purpose of this study is to assess the safety and tolerability of AB598 in participants with advanced malignancies. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Advanced Cancer, Advanced Malignancies, Bladder Cancer
- What is being tested?
- AB598, Zimberelimab and Fluorouracil
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 19 sitesin 3 countries
- Study dates
- 13 Oct 2023to Sep 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
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
- Must have at least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST) guidance
- Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1
- Prior systemic radiation or whole brain radiation therapy must have been completed at least 4 weeks before investigational product (IP) administration. Other palliative radiotherapy must be completed 2 weeks before investigational product administration, if radiation therapy-related AEs have resolved to Grade ≤ 1.
- Monotherapy-specific criteria for dose escalation and PD cohorts:
- Dose Escalation: Participants may have any pathologically confirmed advanced or metastatic solid tumor for which standard therapy has proven ineffective, intolerable, or is considered inappropriate.
- Pharmacodynamic Cohorts: Participants may have any pathologically confirmed advanced or metastatic solid tumors for which standard therapy has proven ineffective, intolerable, or is considered inappropriate. Participants must be able to undergo collection of a fresh frozen biopsy during screening, as well as provide an on-treatment fresh frozen biopsy.
Show all 10Show fewer
- Dose Expansion cohort criteria:
- Histologically confirmed, documented diagnosis of HER2-negative locally advanced unresectable or metastatic gastric or GEJ adenocarcinoma.
- No prior systemic treatment for locally advanced unresectable or metastatic disease.
- Cannot have progressed within 6 months of prior platinum-based chemotherapy for earlier stage disease.
Who cannot join
- Use of any live vaccines against infectious diseases (eg, influenza, varicella) within 4 weeks (28 days) of initiation of study
- Underlying medical conditions or AEs that, in the investigator or sponsor's opinion, will make the administration of the study drugs hazardous
- Any active or documented history of autoimmune disease including but not limited to inflammatory bowel disease, celiac disease, Wegner syndrome, Hashimoto syndrome, systemic lupus erythematosus, scleroderma, sarcoidosis, or autoimmune hepatitis, within 3 years of the first dose of study treatment
- History of trauma or major surgery within 28 days prior to the first dose of study drug
- Treatment with systemic immunosuppressive medication within 2 weeks prior to initiation of study treatment, or anticipation of need for systemic immunosuppressant medication during study treatment with certain protocol specified exceptions
- Note: Other protocol defined Inclusion/Exclusion criteria may apply.
Trial locations and contacts
19 sites in 3 countries.
19 sites in 3 countries
United States14 sites
Research Site
Canton, Ohio, 44718
Research Site
Cleveland, Ohio, 44106
Research Site
Detroit, Michigan, 48201
Research Site
Fairfax, Virginia, 22031
Research Site
Goshen, Indiana, 46526
Research Site
Hinsdale, Illinois, 60521
Research Site
Irving, Texas, 75039
Research Site
Jacksonville, Florida, 32224
Research Site
Lake City, Florida, 32024
Research Site
New Brunswick, New Jersey, 08901
Research Site
Phoenix, Arizona, 85054
Research Site
Rochester, Minnesota, 55905
Research Site
Santa Monica, California, 90095
Research Site
Santa Rosa, California, 95403
Taiwan4 sites
Research Site
Kaohsiung City
Research Site
Tainan
Research Site
Taipei
Research Site
Taoyuan City
About this study
Official title: A Phase 1/1b Study to Evaluate the Safety and Tolerability of AB598 Monotherapy and Combination Therapy in Participants With Advanced Malignancies
The primary purpose of this study is to assess the safety and tolerability of AB598 in participants with advanced malignancies.
- Conditions
- Advanced Cancer, Advanced Malignancies, Bladder Cancer, Cervical Cancer, Esophageal Cancer, Gastric Cancer
- Being tested
- AB598, Zimberelimab, Fluorouracil, Leucovorin, Oxaliplatin
- Keywords
- AB598, AB122, Zimberelimab
- Medical subject headings
- Urinary Bladder Neoplasms, Uterine Cervical Neoplasms, Esophageal Neoplasms, Stomach Neoplasms, Squamous Cell Carcinoma of Head and Neck, Carcinoma, Non-Small-Cell Lung, Ovarian Neoplasms, Carcinoma, Renal Cell
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AB598Drug
Administered as specified in the treatment arm
ZimberelimabDrug
Also called AB122
Administered as specified in the treatment arm
FluorouracilDrug
Administered as specified in the treatment arm
LeucovorinDrug
Administered as specified in the treatment arm
OxaliplatinDrug
Administered as specified in the treatment arm
| Study group | Role | What they receive |
|---|---|---|
| Dose Escalation Cohort 1 | Experimental | Participants will receive AB598 intravenous (IV) infusion once every 3 weeks Receives: Drug: AB598 |
| Dose Escalation Cohort 2 | Experimental | Participants will receive AB598 IV infusion once every 3 weeks Receives: Drug: AB598 |
| Dose Escalation Cohort 3 | Experimental | Participants will receive AB598 IV infusion once every 3 weeks Receives: Drug: AB598 |
| Dose Escalation Cohort 4 | Experimental | Participants will receive AB598 IV infusion once every 3 weeks Receives: Drug: AB598 |
| Pharmacodynamic Cohort 1 | Experimental | Participants will receive AB598 IV infusion once every 3 weeks Receives: Drug: AB598 |
| Pharmacodynamic Cohort 2 | Experimental | Participants will receive AB598 IV infusion once every 3 weeks Receives: Drug: AB598 |
| Pharmacodynamic Cohort 3 | Experimental | Participants will receive AB598 IV infusion once every 3 weeks Receives: Drug: AB598 |
| Dose Expansion Gastric/GEJ Cancer (phase 1b) | Experimental | Participants will receive AB598 IV infusion every 2 weeks in combination with zimberelimab and FOLFOX (oxaliplatin, leucovorin, fluorouracil) Receives: Drug: AB598; Drug: Zimberelimab; Drug: Fluorouracil; Drug: Leucovorin; Drug: Oxaliplatin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)
Measured: Up to 2 years
Dose Escalation Cohorts: Number of Participants with Dose-Limiting Toxicities (DLTs)
Measured: Up to 2 years
Secondary outcomes (6)
Area Under the Concentration-Time Curve from Administration ("0") to the Time That the Drug is No Longer Present in the Body ("infinity") (AUC 0-inf) in Whole Blood and Plasma
Measured: Predose, Up to 4 hours post dose
Maximum Concentration (Cmax) in Whole Blood and Plasma
Measured: Predose, Up to 4 hours post dose
Time to Maximum Concentration (Tmax) in Whole Blood and Plasma
Measured: Predose, Up to 4 hours post dose
Number of Participants Who Test Positive for Antidrug Antibodies (ADAs) to AB598
Measured: Up to 2 years
Objective Response Rate (ORR)
Measured: Up to 2 years
Dose Expansion Cohort: Duration of Response (DOR)
Measured: Up to 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Jun 2023
- Study start13 Oct 2023
- Primary completionSep 2027 (estimated)
- Study completionSep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Advanced CancerStudies 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
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Arcus Biosciences, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Arcus Biosciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05891171
- Sponsor's protocol ID
- ARC-25
- Acronym
- ARC-25
- Status last verified
- Apr 2026
- First submitted
- 26 May 2023
- Last updated
- 2 Nov 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Arcus will provide access to individual de-identified participant data and related study documents (e.g., protocol, Statistical Analysis Plan \[SAP\], Clinical Study Report \[CSR\]) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. For more information, please visit our website.
Study at a glance
From the registry record, last updated by the sponsor on 2 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1/1b Study to Evaluate the Safety and Tolerability of AB598 Monotherapy and Combination Therapy in Participants With Advanced Malignancies
- ClinicalTrials.gov ID
- NCT05891171
- Acronym / sponsor ID
- ARC-25 / ARC-25
- Conditions
- Advanced Cancer, Advanced Malignancies, Bladder Cancer, Cervical Cancer, Esophageal Cancer, Gastric Cancer
- Keywords
- AB598, AB122, Zimberelimab
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Arcus Biosciences, Inc.Industry (pharma, biotech, devices)
- Study start
- 13 Oct 2023 (actual)
- Primary completion
- Sep 2027 (estimated)
- Study completion
- Sep 2027 (estimated)
- First posted
- 6 Jun 2023 (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 primary purpose of this study is to assess the safety and tolerability of AB598 in participants with advanced malignancies.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 8
| Arm | Type | Receives |
|---|---|---|
| Dose Escalation Cohort 1 | Experimental | Drug: AB598Participants will receive AB598 intravenous (IV) infusion once every 3 weeks |
| Dose Escalation Cohort 2 | Experimental | Drug: AB598Participants will receive AB598 IV infusion once every 3 weeks |
| Dose Escalation Cohort 3 | Experimental | Drug: AB598Participants will receive AB598 IV infusion once every 3 weeks |
| Dose Escalation Cohort 4 | Experimental | Drug: AB598Participants will receive AB598 IV infusion once every 3 weeks |
| Pharmacodynamic Cohort 1 | Experimental | Drug: AB598Participants will receive AB598 IV infusion once every 3 weeks |
| Pharmacodynamic Cohort 2 | Experimental | Drug: AB598Participants will receive AB598 IV infusion once every 3 weeks |
| Pharmacodynamic Cohort 3 | Experimental | Drug: AB598Participants will receive AB598 IV infusion once every 3 weeks |
| Dose Expansion Gastric/GEJ Cancer (phase 1b) | Experimental | Drug: AB598, Drug: Zimberelimab, Drug: Fluorouracil, Drug: Leucovorin, Drug: OxaliplatinParticipants will receive AB598 IV infusion every 2 weeks in combination with zimberelimab and FOLFOX (oxaliplatin, leucovorin, fluorouracil) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Must have at least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST) guidance
- Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1
- Prior systemic radiation or whole brain radiation therapy must have been completed at least 4 weeks before investigational product (IP) administration. Other palliative radiotherapy must be completed 2 weeks before investigational product administration, if radiation therapy-related AEs have resolved to Grade ≤ 1.
- Monotherapy-specific criteria for dose escalation and PD cohorts:
- Dose Expansion cohort criteria:
Key exclusion criteria (6 listed)
- Use of any live vaccines against infectious diseases (eg, influenza, varicella) within 4 weeks (28 days) of initiation of study
- Underlying medical conditions or AEs that, in the investigator or sponsor's opinion, will make the administration of the study drugs hazardous
- Any active or documented history of autoimmune disease including but not limited to inflammatory bowel disease, celiac disease, Wegner syndrome, Hashimoto syndrome, systemic lupus erythematosus, scleroderma, sarcoidosis, or autoimmune hepatitis, within 3 years of the first dose of study treatment
- History of trauma or major surgery within 28 days prior to the first dose of study drug
- Treatment with systemic immunosuppressive medication within 2 weeks prior to initiation of study treatment, or anticipation of need for systemic immunosuppressant medication during study treatment with certain protocol specified exceptions
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 |
|---|---|---|
| AB598Administered as specified in the treatment arm | Drug | Dose Escalation Cohort 1, Dose Escalation Cohort 2, Dose Escalation Cohort 3, Dose Escalation Cohort 4, Dose Expansion Gastric/GEJ Cancer (phase 1b), Pharmacodynamic Cohort 1, Pharmacodynamic Cohort 2, Pharmacodynamic Cohort 3 |
| ZimberelimabAlso: AB122Administered as specified in the treatment arm | Drug | Dose Expansion Gastric/GEJ Cancer (phase 1b) |
| FluorouracilAdministered as specified in the treatment arm | Drug | Dose Expansion Gastric/GEJ Cancer (phase 1b) |
| LeucovorinAdministered as specified in the treatment arm | Drug | Dose Expansion Gastric/GEJ Cancer (phase 1b) |
| OxaliplatinAdministered as specified in the treatment arm | Drug | Dose Expansion Gastric/GEJ Cancer (phase 1b) |
Primary outcome
Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: Up to 2 years
Dose Escalation Cohorts: Number of Participants with Dose-Limiting Toxicities (DLTs)
Time frame: Up to 2 years
6 secondary outcomes
Area Under the Concentration-Time Curve from Administration ("0") to the Time That the Drug is No Longer Present in the Body ("infinity") (AUC 0-inf) in Whole Blood and Plasma
Time frame: Predose, Up to 4 hours post dose
Maximum Concentration (Cmax) in Whole Blood and Plasma
Time frame: Predose, Up to 4 hours post dose
Time to Maximum Concentration (Tmax) in Whole Blood and Plasma
Time frame: Predose, Up to 4 hours post dose
Number of Participants Who Test Positive for Antidrug Antibodies (ADAs) to AB598
Time frame: Up to 2 years
Objective Response Rate (ORR)
Time frame: Up to 2 years
Dose Expansion Cohort: Duration of Response (DOR)
Time frame: Up to 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Nov 2026.
- ARC-25 - Public websiteLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Arcus will provide access to individual de-identified participant data and related study documents (e.g., protocol, Statistical Analysis Plan [SAP], Clinical Study Report [CSR]) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. For more information, please visit our website.
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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.
Medical Director study director
Arcus Biosciences
19 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing AB598, Zimberelimab and Fluorouracil in people with Advanced Cancer and Advanced Malignancies, run by Arcus Biosciences, Inc. at 19 sites in 3 countries.
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 10 inclusion and 6 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: under way, not looking for participants, as of the sponsor's last update on 2 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 19 sites in United States, Taiwan, Australia. 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?
This study is still under way. Results are not available in the source record yet.
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?
Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs) (time frame: Up to 2 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 2 Nov 2026; AzTrials last refreshed its copy on 7 Nov 2026.