Purpose

This is a Phase 2/3, randomized, open-label study for the treatment of patients with HER2-positive Gastric cancer (GC) or Gastroesophageal Junction (GEJ) cancer conducted in two parts. Part A is a single-arm cohort (Cohort A, 40 to 110 patients) will evaluate safety and efficacy of margetuximab plus retifanlimab. Part B has 2 subparts. Cohort B1 has 4 arms (50 patients/arm). Patients will be randomized to margetuximab plus retifanlimab plus chemotherapy, margetuximab plus tebotelimab, plus chemotherapy, margetuximab plus chemotherapy, or trastuzumab plus chemotherapy. The most effective combination with margetuximab from Cohort B1 will be used in Cohort B2. Cohort B2 has 2 arms (250 patients/arm). Patients will be randomized to margetuximab plus retifanlimab or tebotelimab plus chemotherapy, or to trastuzumab plus chemotherapy.

Conditions

Eligibility

Eligible Ages
Over 18 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • Histologically confirmed diagnosis of previously untreated locally advanced unresectable or metastatic HER2+ GC or GEJ adenocarcinoma 1. Prior systemic perioperative treatment is allowed; however the patient must have had a disease-free interval of at least 6 months from end of chemo/surgery 2. Patients receiving perioperative anti-HER2 therapy require testing of HER2 status for eligibility 3. Cohort A: HER2-positive (by IHC 3+) and PD-L1-positive (by IHC with 22C3 CPS ≥ 1%) per central review 4. Cohort B: HER2-positive (by IHC 3+ or IHC 2+ in combination with FISH+) by local review. PD -L1 status is not required for enrollment. - Availability of formalin-fixed, paraffin-embedded tumor specimen, unstained slides or contemporaneous biopsy for tumor target testing - Eastern Cooperative Oncology Group performance status of 0 or 1, verified within 3 days of Day 1 - Life expectancy ≥ 6 months - At least one radiographically measurable target lesion - Acceptable laboratory parameters and adequate organ function

Exclusion Criteria

  • Other malignancy that is progressing or required treatment within the past 5 years, with certain exceptions - Patients with known MSI-H status - History of allogeneic stem cell or tissue/solid organ transplant - Central nervous system metastases - Clinically significant cardiovascular disease, gastrointestinal disorders, pulmonary compromise - Prior neoadjuvant or adjuvant treatment with immunotherapy

Study Design

Phase
Phase 2/Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Intervention Model Description
Cohort A is a single-arm cohort to evaluate safety and efficacy of margetuximab plus retifanlimab. Cohort B Part 1 is a randomized, 4-arm segment to evaluate margetuximab plus retifanlimab plus chemotherapy, margetuximab plus tebotelimab plus chemotherapy, margetuximab plus chemotherapy, vs trastuzumab plus chemotherapy. Cohort B Part 2 is a randomized, 2-arm segment to evaluate margetuximab plus the selected checkpoint inhibitor from Part 1, plus chemotherapy vs. trastuzumab plus chemotherapy.
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Chemotherapy-free arm
margetuximab plus retifanlimab
  • Biological: margetuximab
    margetuximab: Fc-modified anti-HER2 monoclonal antibody: 15 mg/kg IV, Day1 of each 3-week cycle
    Other names:
    • MGAH22
    • Margenza®
  • Biological: Retifanlimab
    Retifanlimab: anti-PD-1 checkpoint inhibitor 375 mg IV, Day 1 of each 3-week cycle.
    Other names:
    • MGA012
    • INCMGA00012
Experimental
Margetuximab, retifanlimab, and chemotherapy arm
margetuximab plus retifanlimab plus investigator choice of chemotherapy options. Chemotherapy options: capecitabine and oxaliplatin (XELOX) or modified 5-FU, leucovorin, and oxaliplatin regimen 6 (mFOLFOX-6)
  • Biological: margetuximab
    margetuximab: Fc-modified anti-HER2 monoclonal antibody: 15 mg/kg IV, Day1 of each 3-week cycle
    Other names:
    • MGAH22
    • Margenza®
  • Biological: Retifanlimab
    Retifanlimab: anti-PD-1 checkpoint inhibitor 375 mg IV, Day 1 of each 3-week cycle.
    Other names:
    • MGA012
    • INCMGA00012
  • Other: Chemotherapy
    Investigator choice of 1 of 2 chemotherapy regimens: XELOX or mFOLFOX6 Chemotherapy XELOX chemotherapy Capecitabine: 1000 mg/m2 as oral capsules twice a day Days 1-14 of each cycle, Oxaliplatin: 130 mg/m2 of Day 1 of each 3-week cycle as IV infusion mFOLFOX6 chemotherapy: Leucovorin: 400 mg/m2 every 2 weeks as IV infusion, 5-FU bolus: 400 mg/m2 every 2 weeks as IV infusion, 5-FU continuous infusion: 2400 mg/m2 every 2 weeks as a 46 hr infusion, Oxaliplatin: 85 mg/m2 every 2 weeks as IV infusion.
Experimental
Margetuximab, tebotelimab and chemotherapy arm
margetuximab plus tebotelimab plus investigator choice of chemotherapy options. Chemotherapy options: capecitabine and oxaliplatin (XELOX) or modified 5-FU, leucovorin, and oxaliplatin regimen 6 (mFOLFOX-6)
  • Biological: margetuximab
    margetuximab: Fc-modified anti-HER2 monoclonal antibody: 15 mg/kg IV, Day1 of each 3-week cycle
    Other names:
    • MGAH22
    • Margenza®
  • Biological: Tebotelimab
    Tebotelimab: anti PD-1, anti-LAG3 bispecific DART (R) molecule 600 mg IV, Day 1 of each 3-week cycle.
    Other names:
    • MGD013
  • Other: Chemotherapy
    Investigator choice of 1 of 2 chemotherapy regimens: XELOX or mFOLFOX6 Chemotherapy XELOX chemotherapy Capecitabine: 1000 mg/m2 as oral capsules twice a day Days 1-14 of each cycle, Oxaliplatin: 130 mg/m2 of Day 1 of each 3-week cycle as IV infusion mFOLFOX6 chemotherapy: Leucovorin: 400 mg/m2 every 2 weeks as IV infusion, 5-FU bolus: 400 mg/m2 every 2 weeks as IV infusion, 5-FU continuous infusion: 2400 mg/m2 every 2 weeks as a 46 hr infusion, Oxaliplatin: 85 mg/m2 every 2 weeks as IV infusion.
Experimental
Margetuximab and chemotherapy arm
margetuximab plus investigator choice of chemotherapy options. Chemotherapy options: capecitabine and oxaliplatin (XELOX) or modified 5-FU, leucovorin, and oxaliplatin regimen 6 (mFOLFOX-6)
  • Biological: margetuximab
    margetuximab: Fc-modified anti-HER2 monoclonal antibody: 15 mg/kg IV, Day1 of each 3-week cycle
    Other names:
    • MGAH22
    • Margenza®
  • Other: Chemotherapy
    Investigator choice of 1 of 2 chemotherapy regimens: XELOX or mFOLFOX6 Chemotherapy XELOX chemotherapy Capecitabine: 1000 mg/m2 as oral capsules twice a day Days 1-14 of each cycle, Oxaliplatin: 130 mg/m2 of Day 1 of each 3-week cycle as IV infusion mFOLFOX6 chemotherapy: Leucovorin: 400 mg/m2 every 2 weeks as IV infusion, 5-FU bolus: 400 mg/m2 every 2 weeks as IV infusion, 5-FU continuous infusion: 2400 mg/m2 every 2 weeks as a 46 hr infusion, Oxaliplatin: 85 mg/m2 every 2 weeks as IV infusion.
Active Comparator
Trastuzumab and chemotherapy arm
Trastuzumab plus investigator choice of chemotherapy options. Chemotherapy options: capecitabine and oxaliplatin (XELOX) or modified 5-FU, leucovorin, and oxaliplatin regimen 6 (mFOLFOX-6)
  • Biological: Trastuzumab
    Anti-HER2 monoclonal antibody 8 mg/kg loading dose and then 6 mg/kg administered IV on Day 1 of each 3-week cycle
    Other names:
    • Herceptin
  • Other: Chemotherapy
    Investigator choice of 1 of 2 chemotherapy regimens: XELOX or mFOLFOX6 Chemotherapy XELOX chemotherapy Capecitabine: 1000 mg/m2 as oral capsules twice a day Days 1-14 of each cycle, Oxaliplatin: 130 mg/m2 of Day 1 of each 3-week cycle as IV infusion mFOLFOX6 chemotherapy: Leucovorin: 400 mg/m2 every 2 weeks as IV infusion, 5-FU bolus: 400 mg/m2 every 2 weeks as IV infusion, 5-FU continuous infusion: 2400 mg/m2 every 2 weeks as a 46 hr infusion, Oxaliplatin: 85 mg/m2 every 2 weeks as IV infusion.

More Details

Status
Active, not recruiting
Sponsor
MacroGenics

Study Contact

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Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.