ArGEN-X Antibody Hits Dose Escalation Goals

ARGX-110, the lead antibody for arGEN-X, has met its translational development goals in the dose-escalation part of a Phase Ib study: all pre-specified biological activity measures –target engagement, effector functions, immune-modulation — were met, according to the company. The study also showed that ARGX-110 has a favorable safety profile and a dose has been selected to advance into the Phase Ib safety and efficacy expansion cohorts, which will start early in 2014 and are expected to report top-line results approximately 12 months later. Those cohorts will include hematology and solid tumor patients.

ARGX-110 is a first-in-class monoclonal antibody potently blocking CD70-induced tumor proliferation and tumor escape from immune surveillance. In addition, the POTELLIGENT-enhanced antibody-dependent cellular cytotoxicity (ADCC) of ARGX-110 enables selective destruction of CD70-positive tumor cells. CD70 is overexpressed in the majority of cancer patients tested to date. Expectations of a favorable therapeutic index stem from its virtual absence in healthy tissues.

In the study, 19 patients with CD70-positive cancer were treated with escalating doses of ARGX-110, up to 10 mg/kg. The results show predictable pharmacokinetics across the dose range. No dose-limiting toxicity was identified. The study is managed jointly by arGEN-X and a consortium of academic institutions in Belgium.