A phase Ia dose-escalation trial of Ametumumab (a fully human monoclonal antibody against epidermal growth factor receptor) in patients with advanced solid malignancies.

Background: Epidermal growth factor receptor (EGFR) is a well-known target for cancer treatment. However, the authorized anti-EGFR monoclonal antibodies generally cause several toxic effects, especially severe cutaneous toxicities as well as infusion reactions, and the clinical indications are limited. Here we developed Ametumumab, a fully human recombinant anti-EGFR monoclonal antibody. Objectives: To assess the safety, tolerability, pharmacokinetics (PK), and immunogenicity of Ametumumab. Design: A first-in-human phase Ia dose escalation study of Ametumumab in patients with advanced solid malignancies. Methods: An open-label, first-in-human dose escalation study was done in 22 patients with advanced malignancies who received six ascending dosages ranging from 75 to 750 mg/m2. Following a single dosage and a 28-day dose-limiting toxicity (DLT) monitoring period, patients were given repeated doses weekly. Blood samples were taken to determine the PK parameters of Ametumumab and anti-drug antibody concentrations. Every 8 weeks, radiographic tumor evaluations were conducted. Results: In this trial, no DLT was observed, and the maximum tolerated dose was not reached at doses up to 750 mg/m2. There were no severe adverse events but mild and moderate adverse effects, such as headache, proteinuria, and rash. Single-dose PK results demonstrated a straightforward linear relationship with dosage escalation. The medication concentrations accumulated and attained steady-state after four rounds of injections. It was calculated that 10 patients with disease control would be observed in the 22 evaluable patients. The disease control rate was 45.5%. Conclusion: The Ametumumab was well tolerated and safe in patients with advanced solid malignancies, exhibiting minimal immunogenicity, a long half-life, high levels of drug exposure in the blood, and preliminary effectiveness. Registration: The trial was registered with CTR20170343 on 10 April 2017, The China Center for Drug Evaluation.