First-In-Human Phase I Study Of Cetugex, A Novel Anti-Egfr Monoclonal Antibody (Mab) With Optimized Glycosylation And Antibody Dependent Cellular Cytotoxicity.

3008 Background: Epidermal growth factor receptor (EGFR) is a validated target in cancer. EGFR antagonists in clinical use do not exploit the full potential of this target. CetuGEX is an IgG1 mAb against EGFR. Fully human and optimized glycosylation lead to a 10- to 250-fold improvement of ADCC-mediated tumor cell killing in all FcγRIIIa allotypes and lack of immunogenic carbohydrate-chains, compared to cetuximab. Methods: Eligible patients with advanced solid tumors, progressing after standard treatment, were enrolled into this phase I, first-in-human, multicenter, single agent dose escalation trial. PK, PD and immunological parameters were assessed. Endpoints were safety and tolerability and secondarily pharmacokinetics, immunogenicity and anti-tumor activity. Results: 41 patients were treated on a q1w (8 dose levels from 12 to 1,370 mg flat dose), or q2w (990 mg flat) schedule. 25 pts had received at least 8 weekly doses (per protocol population [PP]).The most frequently observed drug-related AE were nausea (20%), vomiting (20%), hypertension (20%), almost all low grade and acneiform dermatitis (25%), only grade 1 or 2. Infusion-related reactions (IRR), virtually restricted to the first infusion, were associated with cytokine secretion: IL-6, IL-8, TNFα, IFNγ and IP-10 as marker of macrophage activation. Optimization of infusion scheme and premedication reduced IRRs in severity and frequency from 76% to 57% mainly of low grade. Blood NK cells were reduced as sign of redistribution. Activity was seen over all dose levels. One patient with NSCLC achieved a complete response. One patient with metastatic colorectal cancer had a partial response, another 2 patients with esophageal and gastric cancer without measurable disease at study entry had marked improvement of symptoms and normalization of tumor markers. Additional 15 pts had stable disease lasting from 8 weeks to over a year, including several minor responses, leading to a clinical benefit rate of 46% (19/41) in the overall and 76% (19/25) in the PP population. PK supports q1w and q2w dosing. Conclusions: CetuGEX shows clear signs of activity and acceptable toxicity. Phase II will soon be initiated. Clinical trial information: NCT01222637.