argenx Reports Second Quarter Business Update and Half Year 2016 Financial Results

• Successful Phase 1 multiple ascending dose (MAD) study of ARGX-113
  in healthy volunteers

• Phase 2 study in first auto-immune indication planned to start by year-end

• Cash position strengthened by $40M upfront payment from AbbVie and
  €30M private placement

Management to host conference call today at 3 pm CET / 9 am EDT

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 its second quarter business update and half year financial results for 2016, in accordance with IFRS as adopted by the European Union.

The half year results will be discussed during a conference call and webcast presentation today at 3 pm CET / 9 am EDT. To participate in the conference call, please select your phone number below, and use the confirmation code 49998398. The webcast may be accessed on the homepage of the argenx website at www.argenx.com or by clicking here.

This quarter was a seminal one for us as we made substantial progress against several very important corporate goals: advancing our clinical and other pipeline programs and in closing a significant financing with key U.S. institutional investors as well as entering into a strategic transaction with AbbVie for our oncology candidate AGRX-115. We believe these accomplishments have driven argenx forward to become a new and more substantial company with a full and mature clinical pipeline, an advanced platform and the financial and strategic support to derive value from them, said Tim Van Hauwermeiren, Chief Executive Officer of argenx. During the quarter we announced data from our Phase 1 MAD and SAD studies of ARGX-113 which led to the selection of our Phase 2 dose and demonstrated the drug’s strong safety profile and its ability to rapidly reduce IgG levels in healthy volunteers. Our lead oncology candidate ARGX-110 showed further evidence of anti-tumor activity in T-cell lymphoma patients and is on track to announce top-line data in this expansion cohort by end of year. We are looking forward to executing on our strategic plan for the remainder of 2016 to bring ARGX-113 into two Phase 2 indications and to examine the breadth of potential for ARGX-110 as a monotherapy and a combination agent in TCL and AML.

SECOND QUARTER 2016

• Announced initial results from its Phase 1 multiple ascending dose (MAD) study of ARGX-113 in healthy volunteers. The compound continues to show favorable safety and tolerability across multiple doses and dosing regimens with promising pharmacodynamics effects relating to speed, depth and duration of IgG reduction.
• Published efficacy and safety data from its ARGX-111 Phase 1 expansion study in patients with MET amplified tumors in conjunction with the American Society of Clinical Oncology (ASCO) 2016 Annual Meeting (Chicago, USA). The data confirm ARGX-111 to have a favorable safety profile and to continue to show signs of anti-tumor activity.
• Presented efficacy and safety data from its Phase 1 expansion study of ARGX-110 in patients with T-cell lymphoma (TCL) during an e-poster session at the European Hematology Association (EHA) Annual Congress (Copenhagen, Denmark). The data from the Phase 1 expansion study show evidence of clinical and/or biological anti-tumor activity with ARGX-110 in highly refractory cutaneous TCL & peripheral TCL patients with confirmed overexpression of CD70.
• Entered into placement agreements with several predominant U.S. institutional investors relating to the issue of a total of 2,703,000 new shares for an aggregate amount of €30,003,300. The transaction was led by MPM Oncology Impact Fund with participation from Aquilo Capital, Burrage Capital, DAFNA Capital, Perceptive Advisors and certain other existing and new institutional investors.
• Announced collaboration with AbbVie to develop and commercialize ARGX-115. ARGX-115 is argenx' preclinical-stage human antibody asset targeting the novel immuno-oncology target GARP, a protein believed to contribute to immunosuppressive effects of T-cells. argenx received an upfront payment of $40M.

FINANCIAL HIGHLIGHTS (as of 30 June, 2016) (compared to financial highlights as of 30 June 2015)

• Operating income of EUR 7.0 million (30 June 2015: EUR 4.3 million).
• Net loss of EUR 7.4 million (30 June 2015: EUR 7 million).
• Cash position of EUR 108.7 million (cash, cash-equivalents and financial assets) allowing Company to pursue development of its product portfolio as planned.