Last updated on April 16, 2014 at 7:25 EDT

arGEN-X Reaches Milestone in Simple Antibody(TM) Research and Product Development Collaboration With Shire

September 19, 2013

BREDA, the Netherlands and GHENT, Belgium, September 19, 2013 /PRNewswire/ –

arGEN-X, a clinical stage human monoclonal antibody therapeutics company, announces it
has attained a key success milestone in its SIMPLE Antibody(TM) research and product
development collaboration with the Human Genetic Therapies division of Shire
Pharmaceuticals. The milestone, which triggered an undisclosed payment from Shire, was the
first demonstration of in vivo proof of concept for one of the antibody discovery programs
undertaken in the collaboration.

Under their February 29, 2012 agreement, the companies are collaborating to create
human therapeutic antibodies against complex targets involved in severe, rare genetic
diseases. Shire has an option to license the most promising antibody leads from each
collaborative program for further development and commercialization worldwide, in return
for milestone and royalty payments. Under the terms of the license, arGEN-X has already
received technology access fees and research funding and is eligible to receive
preclinical success payments.

“We are pleased with the excellent progress that has resulted from an outstanding
joint effort between our teams,” said Hans de Haard, PhD, Chief Scientific Officer of
arGEN-X. “This collaboration milestone is testament to the superiority of our proprietary
SIMPLE Antibody(TM) platform and reinforces our brand in the complex targets space.”

About arGEN-X – http://www.arGEN-X.com

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.

arGEN-X’ SIMPLE Antibody(TM) platform generates an unprecedented diversity of high
quality human antibodies, enabling optimal product choice. SIMPLE Antibodies(TM) are able
to address and modulate any disease target, including complex receptors and highly
conserved targets often intractable with other antibody technologies. SIMPLE Antibody(TM)
generated leads are further differentiated as products through enhancement of cell killing
properties (POTELLIGENT(R), licensed from BioWa Inc.) and optimization of circulation time
and distribution in the body (NHance(TM)). ArGEN-X is also developing ABDEG(TM)
technology, to potentiate the clearance of disease-causing autoantibodies.

In January 2013, arGEN-X initiated a Phase Ib clinical trial 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. A Phase Ib trial for ARGX-111, a novel
anti-c-Met antibody to treat diverse solid tumors, was initiated in September 2013.

The SIMPLE Antibody(TM) platform is covered by broad patent claims, enjoys an
independent, unencumbered patent position and is 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

        For further information, please contact:

        Citigate Dewe Rogerson

        David Dible
        Mark Swallow
        T: +44-207-282-2949/2948
        E: david.dible@citigatedr.co.uk
        E: mark.swallow@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