By measuring the circulating serum concentrations of free, unbound MET and EGFR, saturation of targets begun at 350 mg amivantamab for EGFR and 140 mg amivantamab for MET after a single dose, which was consistent with onset of associated on-target toxicities of rash for EGFR and hypoalbuminemia and peripheral edema for MET. The gene discussed is EGFR; the disease is Hypoalbuminemia.