Last updated on April 16, 2014 at 13:38 EDT

arGEN-X Initiates Phase Ib Study of ARGX-110 in Cancer

January 7, 2013

BREDA, the Netherlands, and GHENT, Belgium, January 7, 2013 /PRNewswire/ –

arGEN-X, a biopharmaceutical company specialized in the discovery and development of
highly differentiated human monoclonal antibody therapeutics, announced today the
initiation of a Phase Ib first-in-man cancer study with ARGX-110, its first SIMPLE
Antibody(TM) program to enter the clinic in just three years from initiation of discovery.

ARGX-110 is a first-in-class CD70-targeting monoclonal antibody that addresses both
known mechanisms of action mediated by CD70: tumor cell proliferation and survival and
tumor cell escape from immune surveillance. In addition, POTELLIGENT(R) enhanced Antibody
Dependent Cellular Cytotoxicity (ADCC) of ARGX-110 drives the selective destruction of
CD70 positive tumor cells. The Phase Ib study will utilize a validated
immunohistochemistry test to pre-screen patients for those whose tumors show up-regulation
of CD70.

“CD70 expression is hijacked by cancer cells to stimulate their own growth and escape
the body’s immune surveillance. With ARGX-110 we are focusing on treating both the tumor
and its immune environment with one molecule,” said Alain Thibault, M.D., Chief Medical
Officer at arGEN-X. “ARGX-110 is an excellent example of how our proprietary antibody
discovery technologies can create exciting development candidates with unique and novel
modes of action in cancer. We look forward to the results from this study and to further
progress with this and other antibodies in our pipeline during the next 12 months.”

In preclinical testing, ARGX-110 has shown broad therapeutic potential against CD70
positive lymphomas and lymphocytic leukemias, as well as solid tumors including those
caused by oncogenic viruses, such as nasopharyngeal, cervical, and hepatocellular
carcinomas. For Ahmad Awada, MD, PhD of the Jules Bordet institute and principal
investigator of this trial, “CD70 may be a unifying driver mechanism for different subsets
of cancer that are still poorly understood.”

About the ARGX-110 Phase Ib Trial

The Phase Ib study being undertaken by arGEN-X is an adaptive dose escalation with
safety expansion trial in around 54 patients, to be conducted by a consortium of leading
academic institutions in Belgium. In addition to traditional clinical and PK endpoints,
biomarkers critical to understanding CD70 biology will be researched extensively in the
course of the trial. Results on the recommended dose for future pivotal trials are
expected by end Q4, 2013.

About arGEN-X

arGEN-X is a clinical stage biopharmaceutical company that is rapidly leveraging the
power of its proprietary SIMPLE Antibody(TM) platform to generate fully human, highly
differentiated antibodies with outstanding therapeutic potential. The platform excels in
delivering large panels of ultra-potent, functionally diverse antibodies against complex
disease targets, especially cell surface receptors and highly conserved proteins.

arGEN-X has validated its technology on multiple diverse target classes to date.
Following a successful collaboration with Eli Lilly & Co., arGEN-X entered earlier this
year into a strategic alliance with Shire, focused on the discovery and development of
antibody therapeutics against complex targets implicated in rare diseases.

The superior choice that arGEN-X brings to antibody discovery enables it to prioritize
leads with best-in-class therapeutic properties with an increased probability of
development success. The consistent manufacturability of SIMPLE Antibody(TM) leads also
makes for a seamless transition from discovery into development. Consequently, arGEN-X has
developed a pipeline of therapeutic candidates in only three years of operations, the
first of which, a novel anti-IL-6 monoclonal antibody, ARGX-109, was licensed to RuiYi in
October 2012 for development and commercialization worldwide.

In November 2012, arGEN-X filed a first CTA for ARGX-110, its most advanced SIMPLE
Antibody(TM) program modulating CD70 via a unique mode of action in hematological and
virally-induced solid tumors, as well as in autoimmunity. A second CTA for ARGX-111, a
novel anti-c-Met antibody to treat diverse solid tumors, is on track for filing in 2013.

arGEN-X is applying NHance(TM) and POTELLIGENT(R) technologies to complement the
therapeutic properties of leads generated from its SIMPLE Antibody(TM) platform, both in
partnership and for its proprietary pipeline. SIMPLE Antibody(TM) and NHance(TM) platforms
are covered by broad patent claims, enjoy an independent, unencumbered patent position and
are free of target gatekeeping restrictions.

SIMPLE stands for Superior Immunodiversity with Minimal Protein Lead Engineering.

arGEN-X(TM), SIMPLE Antibody(TM) and NHance(TM) are deposited trademarks of arGEN-X

POTELLIGENT(R) is a deposited trademark of BioWa Inc.

        For further information, please contact:

        Citigate Dewe Rogerson
        David Dible
        Mark Swallow
        Nina Enegren
        T: +44-207-282-2949/2948/1050
        E: david.dible@citigatedr.co.uk

        Tim Van Hauwermeiren, MSc, eMBA
        Chief Executive Officer
        T: +31-6-122-85-257
        E: tim.vh@arGEN-X.com

        Debbie Allen, Ph.D.
        Senior Director, Business Development
        T: +44-7974-979479
        E: dallen@arGEN-X.com


Source: PR Newswire