A Clinical Trial of a New Combination Treatment, Domvanalimab and Zimberelimab, Plus Chemotherapy, for People With an Upper Gastrointestinal Tract Cancer That Cannot be Removed With Surgery That Has Spread to Other Parts of the Body (STAR-221)
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ClinicalTrials.gov Identifier: NCT05568095 |
Recruitment Status :
Recruiting
First Posted : October 5, 2022
Last Update Posted : May 17, 2023
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Condition or disease | Intervention/treatment | Phase |
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Advanced Upper Gastrointestinal Tract Adenocarcinoma | Drug: Domvanalimab Drug: Zimberelimab Drug: Capecitabine Drug: Fluorouracil Drug: Leucovorin Drug: Oxaliplatin Drug: Nivolumab | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 970 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | A Randomized, Open-Label, Multicenter Phase 3 Trial of Domvanalimab, Zimberelimab, and Chemotherapy Versus Nivolumab and Chemotherapy in Participants With Previously Untreated Locally Advanced Unresectable or Metastatic Gastric, Gastroesophageal Junction, and Esophageal Adenocarcinoma |
Actual Study Start Date : | November 21, 2022 |
Estimated Primary Completion Date : | September 2026 |
Estimated Study Completion Date : | January 2027 |

Arm | Intervention/treatment |
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Experimental: Domvanalimab + Zimberelimab + FOLFOX/CAPOX (PI Choice)
Participants in this arm will receive Domvanalimab and zimberelimab doses once every 4 weeks (Q4W) in addition to chemotherapy with FOLFOX (oxaliplatin, leucovorin, fluorouracil) once every 2 weeks (Q2W) or Domvanalimab and zimberelimab once every 3 weeks (Q3W) in addition to chemotherapy with CAPOX (capecitabine and oxaliplatin) Q3W.
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Drug: Domvanalimab
Intravenous (IV) Aqueous Solution
Other Name: AB154 Drug: Zimberelimab IV Aqueous Solution
Other Name: AB122 Drug: Capecitabine Oral Tablets Drug: Fluorouracil IV Aqueous Solution Drug: Leucovorin IV Aqueous Solution Drug: Oxaliplatin IV Aqueous Solution |
Active Comparator: Nivolumab + FOLFOX/CAPOX (PI Choice)
Participants in this arm will receive Nivolumab Q2W and FOLFOX Q2W or Nivolumab Q3W + CAPOX Q3W.
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Drug: Capecitabine
Oral Tablets Drug: Fluorouracil IV Aqueous Solution Drug: Leucovorin IV Aqueous Solution Drug: Oxaliplatin IV Aqueous Solution Drug: Nivolumab IV Aqueous Solution |
- Overall survival [ Time Frame: From randomization until death from any cause (Approximately 15 months) ]
- Progression-free survival (PFS) [ Time Frame: Approximately 15 months ]
- Objective response rate (ORR) [ Time Frame: Approximately 15 months ]
- Duration of response (DOR) [ Time Frame: Approximately 15 months ]
- Incidence and severity of adverse events (AEs) and serious adverse events (SAEs) [ Time Frame: Approximately 15 months ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Age >= 18 years at the time of signing the informed consent.
- Capable of giving signed informed consent which is in compliance with the requirements and restrictions listed in the informed consent form (ICF) and in protocol.
- Histologically confirmed diagnosis of locally advanced unresectable or metastatic gastric, GEJ, or esophageal adenocarcinoma.
- Eastern Cooperative Oncology Group (ECOG) Performance Score of 0-1.
- At least one measurable target lesion per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1.
Exclusion Criteria:
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Underlying medical or psychiatric conditions that, in the investigator's or sponsor's opinion, will make the administration of study-specified therapy hazardous, including but not limited to:
- Interstitial lung disease, including history of interstitial lung disease or non-infectious pneumonitis. Active viral, bacterial, or fungal infections requiring parenteral treatment within 14 days of randomization.
- Clinically significant cardiovascular disease, such as New York Heart Association Class II or greater cardiac disease or cerebrovascular accident within 3 months prior to randomization, unstable angina, or new onset angina within 3 months prior to randomization, myocardial infarction within 6 months prior to randomization, or unstable arrhythmia within 3 months prior to randomization.
- History of prior solid-organ transplantation, including allogenic bone marrow transplantation.
- Dementia, psychiatric, or substance abuse disorders that would interfere with satisfying the requirements of the trial.
- Known human epidermal growth factor receptor 2 (HER-2) positive tumor.
- Known untreated, symptomatic, or actively progressing central nervous system (CNS) (brain) metastases. Participants with leptomeningeal metastases are excluded from enrollment.
- Received prior systemic treatment for locally advanced unresectable or metastatic gastric, GEJ, or esophageal adenocarcinoma.
- Disease progression within 6 months of neoadjuvant or adjuvant chemotherapy.
Other protocol defined Inclusion/Exclusion criteria may apply.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05568095
Contact: Medical Director | +1-510-462-3330 | clinicalTrialInquiry@arcusbio.com |

Study Director: | Medical Director | Arcus Biosciences |
Responsible Party: | Arcus Biosciences, Inc. |
ClinicalTrials.gov Identifier: | NCT05568095 |
Other Study ID Numbers: |
STAR-221 2022-002222-27 ( EudraCT Number ) jRCT2051220179 ( Registry Identifier: Japan Registry of Clinical Trials ) MOH_2023-04-30_012590 ( Registry Identifier: Israel Clinical Research Site - MyTrials ) |
First Posted: | October 5, 2022 Key Record Dates |
Last Update Posted: | May 17, 2023 |
Last Verified: | May 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | 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. |
URL: | https://trials.arcusbio.com/our-transparency-policy |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Domvanalimab Zimberelimab Nivolumab Advanced upper gastrointestinal tract adenocarcinoma |
Gastroesophageal junction cancer Esophageal adenocarcinoma Gastric cancer Gastric adenocarcinoma |
Adenocarcinoma Carcinoma Neoplasms, Glandular and Epithelial Neoplasms by Histologic Type Neoplasms Leucovorin Fluorouracil Capecitabine Oxaliplatin Nivolumab Antimetabolites Molecular Mechanisms of Pharmacological Action |
Antimetabolites, Antineoplastic Antineoplastic Agents Immunosuppressive Agents Immunologic Factors Physiological Effects of Drugs Antineoplastic Agents, Immunological Immune Checkpoint Inhibitors Antidotes Protective Agents Vitamin B Complex Vitamins Micronutrients |