arGEN-X Initiates Phase IbStudy of ARGX-111 in Cancer

BREDA, the Netherlands, and GHENT, Belgium, September 17, 2013 /PRNewswire/ --

SIMPLE Antibody™ with unique mode of action addressing c-Met positive tumors

arGEN-X, a clinical stage human monoclonal antibody therapeutics company, announces today the CTA filing of a first-in-man Phase Ib cancer study with ARGX-111, its second proprietary SIMPLE Antibody™ product to enter the clinic this year.

ARGX-111 is a c-Met-targeting human monoclonal antibody that modulates all known mechanisms of action of the receptor. As well as best-in-class blocking of both ligand dependent and independent signalling through c-Met, ARGX-111 benefits from POTELLIGENT^®-enhanced Antibody Dependent Cellular Cytotoxicity (ADCC), which drives the immune system to destroy c-Met positive tumor cells. Owing to this unique combination of therapeutic attributes, ARGX-111 has demonstrated superior therapeutic potential in both solid and hematological malignancies when compared to established biologic and small molecule-based c-Met therapies. ARGX-111  has  been shown to be safe and well-tolerated in non-human primate studies.

The Phase Ib study will enroll patients with tumors that have been pre-screened for over-expression of c-Met. Because of the known role of c-Met activation in promoting the metastatic potential of tumor cells, the study will also document the eradication of those patients' circulating tumor cells (CTCs), which are known to be precursors of advancing disease.

"ARGX-111 has all of the attributes to become the next-generation c-Met inhibitor of choice, given it combines best-in-class blockade of receptor function with enhanced ADCC. With such a compelling therapeutic profile, we are confident that ARGX-111 has the potential both to treat established tumors and to eradicate CTCs before they seed metastases," said Alain Thibault, M.D., Chief Medical Officer at arGEN-X. "ARGX-111 is an excellent example of how our suite of antibody technologies enables us to generate exciting development candidates with multiple modes of action within a single therapeutic entity."

Ahmad Awada, M.D., Ph.D. of the Jules Bordet Institute, Brussels, Belgium, and Principal Investigator of the study, commented further: "The field of c-Met inhibition is one that offers significant promise in the fight against cancer. Therefore, we are very excited to be involved in the first ever clinical trial with ARGX-111, a potentially best-in-class molecule for the treatment of a broad range of solid and hematological cancers."

About the ARGX-111 Phase Ib Trial

The Phase Ib study being undertaken by arGEN-X includes an adaptive dose escalation scheme, to be followed by a safety cohort expansion.  Approximately 35 patients will be enrolled by a consortium of leading academic institutions in Belgium. In addition to traditional clinical and PK endpoints, biomarkers critical to understanding the effect of ARGX-111 on c-Met biology will be researched during the course of the trial.

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™ platform generates an unprecedented diversity of high quality human antibodies, enabling optimal product choice. SIMPLE Antibodies™ are able to address and modulate any disease target, including complex receptors and highly conserved targets often intractable with other antibody technologies. SIMPLE Antibody™ generated leads are further differentiated as products through enhancement of cell killing properties (POTELLIGENT^®, licensed from BioWa Inc.) and optimization of circulation time and distribution in the body (NHance™). ArGEN-X is also developing ABDEG™ 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™ program modulating CD70 via a unique mode of action in hematological and virally-induced solid tumors. A second CTA for ARGX-111, a novel anti-c-Met antibody to treat diverse solid tumors, is the subject of this press release.

The SIMPLE Antibody™ 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™, SIMPLE Antibody™ and NHance™ are deposited trademarks of arGEN-X BV.

For further information, please contact:

Citigate Dewe Rogerson
David Dible
Mark Swallow
Nina Enegren
T: +44(0)207-282-2949/2948/1050
E: david.dible@citigatedr.co.uk

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

Alain Thibault, M.D.
Chief Medical Officer
T: +32-471-81-71-24
E: athibault@argen-x.com