arGEN-X reports that Phase Ib cancer study with ARGX-110 antibody meets translational development goals

Dose confirmed for Phase Ib safety and efficacy expansion study

arGEN-X announces that the dose-escalation part of a Phase Ib study with its lead antibody ARGX-110 has met its translational development goals: all pre-specified biological activity measures (e.g. target engagement, effector functions, immune-modulation) were met. The study also showed that ARGX-110 has a favourable 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.

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 favourable 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. For Ahmad Awada, MD PhD, principal investigator of the study at the Jules Bordet Institute (Brussels, Belgium), "these results, at the clinical and immunological levels, open the door to study further the antibody as a single agent and in combination trials with small molecules and other immune checkpoint inhibitors."

Based on these data, arGEN-X will begin enrolment to hematology and solid tumor safety and efficacy expansion cohorts early in 2014 and report top-line results approximately 12 months later. According to Alain Thibault, MD, Chief Medical Officer, "We have consistent biomarker data that confirms our understanding of CD70 and the three mechanisms of action of ARGX-110. This is speeding up our program, and we may be in a position to select promising indications for Phase II development by the end of 2014."