Last updated on April 20, 2014 at 7:43 EDT

ARGX-110, a Novel Anti-CD70 Antibody, Meets Translational Development Goals in Dose Escalation Part of Phase Ib Cancer Study

December 17, 2013

BREDA, The Netherlands and GHENT, Belgium, December 17, 2013 /PRNewswire/ –

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(R
)-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.”

About the ARGX-110 Study

The Phase Ib study (ClinicalTrials.gov Identifier: NCT01813539) consists of a dose
escalation followed by adaptive safety and efficacy expansion cohorts conducted in
patients with advanced, refractory cancer. The patient enrichment strategy relies on
individual tumor screening for CD70 utilizing a reproducible immunohistochemistry method.
In addition to traditional clinical and PK/PD endpoints, biomarkers documenting the three
modes of action of ARGX-110 are being evaluated. Patient enrolment is planned at 90
CD70-positive patients with either haematological or solid tumors. The study is managed
jointly by arGEN-X and a consortium of leading academic institutions in Belgium.

About arGEN-X

arGEN-X is a clinical stage human therapeutic antibody company that is rapidly
developing a product pipeline using its unique suite of antibody technologies. arGEN-X is
creating first and best in class antibody therapeutics with highly differentiated target
product profiles. Its therapeutic antibody programs, focused on cancer and autoimmune
indications, are designed to deliver tangible benefits to patients with these diseases.

        For further information, please contact:

        Tim Van Hauwermeiren
        Chief Executive Officer
        T +32(0)9-243-40-70

        Debbie Allen
        Senior Director, Business Development
        T +44(0)7974-979479
        E info@arGEN-X.com

        Mark Swallow/David Dible
        Citigate Dewe Rogerson
        T +44(0)207-282-2949



Source: PR Newswire