argenx launches Phase I/II study of ARGX-110 in combination with azacitidine in newly diagnosed AML patients

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 initiation of a Phase I/II clinical trial of ARGX-110 in combination with azacitidine in newly diagnosed, elderly acute myeloid leukemia (AML) patients. ARGX-110 is the Company’s SIMPLE Antibody™ targeting CD70. Azacitidine is a hypomethylating agent that upregulates CD70 expression on AML blasts, and is currently the standard of care treatment for elderly AML patients.

AML blasts and leukemic stem cells of newly diagnosed AML patients strongly overexpress CD70, regardless genetic factors or risk class. Targeting CD70 has proven to be a very promising therapeutic approach in various preclinical models of AML. The idea of combining ARGX-110 with the current standard of care azacitidine, which seems to sensitize cancer cells to a CD70 treatment, is an exciting one since it allows us to go into the first-line therapy setting, commented Tim Van Hauwermeiren, CEO of argenx. This trial marks the first combination study for ARGX-110. We believe that combination therapies for cancer will be a mainstay approach to enhance synergistic mechanisms and we are eager to see how ARGX-110 and azacitidine may support this hypothesis in newly diagnosed AML patients.

The Phase I/II trial is an open-label, dose-escalating study (Phase I) with a proof-of-concept cohort (Phase II). In this Phase I study safety and tolerability will be determined whilst for the Phase II efficacy will be assessed in up to 42 newly diagnosed AML patients in total. Top-line data from the dose escalation are expected in about 18 months.

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, who won together with Prof Manz from the University Hospital of Zürich, the prestigious 2016 Otto Naegeli Prize for his breakthrough research on CD70/CD27 signaling with therapeutic potential for cancer patients.

About AML

AML develops from immature blood cells produced in the bone marrow that become myeloblasts (also termed blasts or leukaemia cells). All these types of leukaemia cells rapidly multiply in the bone marrow resulting in limited room for healthy 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

+32 (0)477 77 29 44

+32 (0)9 310 34 19

Beth DelGiacco (US IR)

Stern Investor Relations

+1 212 362 1200

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