Amivantamab for the Treatment of Metastatic EGFR or MET-Amplified Esophagogastric Cancer

Inclusion Criteria

• Subject or legally authorized representative is willing and able to provide written informed consent
• Patients with previously treated metastatic or unresectable histologically-confirmed esophagogastric cancer who have received at least 1 line of therapy
• EGFR or MET amplification by tissue-next generation sequencing (NGS) with copy number >= 8 and/or ctDNA amplification by any Food and Drug Administration (FDA) and Clinical Laboratory Improvement Amendments (CLIA)-approved assay
• No prior receipt of an EGFR or MET inhibitor for esophagogastric cancer. (Note: if a patient previously received a EGFR inhibitor, but subsequently demonstrated a MET amplification, or previously received a MET inhibitor, but subsequently demonstrated an EGFR-amplification, inclusion is permitted)
• Patients with HER2+ (immunohistochemistry [IHC] 3+ or IHC 2+/fluorescence in situ hybridization [FISH]+) tumors must have progressed on trastuzumab
• Measurable disease based on RECIST 1.1
• >= 18 years of age on day of signing informed consent
• Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2
• Hemoglobin >= 9 g/dL
• Absolute neutrophil count (ANC) >= 1.0 x 10^9 /L
• Platelets >= 75 x 10^9/L
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =< 3 x upper limit of normal (ULN) (=< 5 x ULN for subjects with liver metastases)
• Total bilirubin =< 1.5 x ULN; subjects with Gilbert’s syndrome can enroll if conjugated bilirubin is within normal limits
• Serum creatinine < 1.5 x ULN or if available, calculated or measured creatinine clearance > 50 mL/min/1.73 m^2
• Women of childbearing potential and male patients with women of childbearing potential partners must be willing to use an adequate method of contraception

Exclusion Criteria

• Prior chemotherapy, targeted small molecule therapy, or biological therapy, within 2 weeks prior to study day 1 or who has not recovered (i.e., =< grade 1 or at baseline) from adverse events due to a previously administered agent (excluding alopecia)
• If subject received major surgery, they must have recovered adequately prior to starting therapy
• Known additional malignancy that is progressing or requires active treatment. Exceptions include basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy
• Known active hepatitis B (e.g., hepatitis B surface antigen [HBsAg] reactive or polymerase chain reaction detectable) * Note: Subjects with a prior history of hepatitis B virus (HBV) demonstrated by positive hepatitis B core antibody are eligible if they have at screening 1) a negative HBsAg and 2) a HBV DNA (viral load) below the lower limit of quantification, per local testing. Subjects with a positive HBsAg due to recent vaccination are eligible if HBV DNA (viral load) is below the lower limit of quantification, per local testing
• Known active hepatitis C (e.g., hepatitis C virus [HCV] ribonucleic acid [RNA] [qualitative] is detected) * Note: Subjects with a prior history of HCV, who have completed antiviral treatment and have subsequently documented HCV RNA below the lower limit of quantification per local testing are eligible
• Other clinically active or chronic liver disease
• Subject has uncontrolled inter-current illness, including but not limited to poorly controlled diabetes, ongoing or active infection (i.e., has discontinued all antibiotics for at least one week prior to first dose of study drug), or psychiatric illness/social situation that would limit compliance with study requirements. Subjects with medical conditions requiring chronic continuous oxygen therapy are excluded
• Pulmonary embolism (PE) and deep vein thrombosis (DVT), within 1 month of start of study drug
• Myocardial infarction, unstable angina, stroke, transient ischemic attack (TIA), or coronary/peripheral artery bypass graft, or any acute coronary syndrome within 6 months of start of study drug
• Congestive heart failure defined as New York Heart Association (NYHA) class III-IV or hospitalization for congestive heart failure (any NYHA class) within 6 months of start of study drug
• Interstitial lung disease (ILD), including drug-induced ILD or radiation pneumonitis requiring treatment with prolonged steroids or other immune suppressive agents that is unresolved or resolved within the last 3 months
• Immune-mediated rash from checkpoint inhibitors that has not resolved prior to enrollment
• Known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial, in the opinion of the treating investigator
• Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the pre-screening or screening visit through 6 months after the last dose of trial treatment
• Prisoners, or subjects who are compulsory detained