argenx announces publication of seminal data supporting the therapeutic potential of ARGX-110 for acute myeloid leukemia in the Journal of Experimental Medicine

Breda, the Netherlands / Ghent, Belgium– argenx (Euronext Brussels: ARGX), a clinical-stage biopharmaceutical company focused on creating and developing differentiated therapeutic antibodies for the treatment of cancer and severe autoimmune diseases, today announced the publication of new preclinical data on the CD70/CD27 pathway that provide further rationale for ARGX-110 therapy for the treatment of acute myeloid leukemia (AML). ARGX-110, a SIMPLE Antibody™ targeting CD70, is currently being evaluated in a Phase I/II study in combination with azacitidine in newly diagnosed AML patients.

Data published by argenx collaborator Prof. Adrian Ochsenbein at the University of Bern, demonstrate that CD70/CD27 is highly expressed on AML blasts and leukemic stem cells in newly diagnosed AML patients, regardless of cytogenetic factors, or the patient’s risk class. The published data show the CD70/CD27 pathway to be critical in the biology of leukemic stem cells, and therapeutic intervention using a CD70-targeted antibody to enable selective targeting of leukemic stem cells without impacting hematopoietic stem cells, resulting in a survival benefit in preclinical AML models.

The published data from Prof Ochsenbein’s lab continue to support our rationale to evaluate ARGX-110 in newly diagnosed AML patients based on the important presence of the CD70 target in the disease pathogenesis and its demonstrated role in survival, commented Nicolas Leupin, MD, Chief Medical Officer of argenx. We are very committed to our recently initiated Phase I/II study of ARGX-110 in combination with standard of care azacitidine as we believe this target represents an innovative and differentiated approach to the disease, further proven by this seminal data underscoring the role of CD70 in acute myeloid leukaemia (AML).

A link to the abstract can be accessed at:

About ARGX-110

ARGX-110 is a SIMPLE Antibody™ targeting CD70, an immune checkpoint target involved in hematological malignancies, several solid tumors and severe autoimmune diseases. ARGX-110 works in three ways: i) blocks growth of tumor cells, ii) kills cancer cells and iii) restores immune surveillance against tumors(Silence K. et al. mAbs 2014; 6 (2):523-532). ARGX-110 is currently being evaluated in hematological and solid tumors. Preclinical work on ARGX-110 in AML was done in collaboration with the Tumor Immunology Lab of Prof. A. F. Ochsenbein at the University of Bern. Prof. Ochsenbein won the prestigious 2016 Otto Naegeli Prize for their breakthrough research on CD70/CD27 signaling with therapeutic potential for cancer patients.

About AML

AML is a neoplasia of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that build up in the bone marrow and interfere with the production of normal blood cells. AML has the lowest 5-year survival rate of all blood malignancies (~5-20%) and primarily affects the eldery. Patients above 65 years old are unfit for stem cell transplantation and are often put on palliative treatment. Around 40% of these patients receive azacitidine, as it has been shown to improve the overall survival rate.

-Azacitidine (Vidaza®, Celgene)-

About argenx

argenx combines the diversity of the llama immune system with antibody engineering to advance a clinical pipeline to treat patients with cancer and autoimmune diseases. Our platforms allow us to unlock novel and complex targets and develop antibody-based drugs designed for longer duration of effect and greater efficacy. The strength of our team, our deep understanding of the biology, and our committed collaborations with industry leaders contribute to the success of our journey.

For further information, please contact:

Joke Comijn, Corporate Communications Manager

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+32 (0)9 310 34 19

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Beth DelGiacco (US IR)

Stern Investor Relations

+1 212 362 1200

[email protected]

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