=argenx (ARGX) : positive results in mid-stage MG study

Breda, the Netherlands / Ghent, Belgium - argenx (Euronext & Nasdaq: ARGX) a clinical-stage biotechnology company developing a deep pipeline of differentiated antibody-based therapies for the treatment of severe autoimmune diseases and cancer.

• Headquarters: Rotterdam, Netherlands
• Founded: 2008
• argenx.com

Phase 2 proof-of-concept study assessing ARGX-113 (efgartigimod) in patients with myasthenia gravis (MG), an autoimmune neuromuscular disorder characterized by weakness in the voluntary muscles.
Efgartigimod is an antibody fragment designed to block antibody recycling through a receptor called FcRn which induces rapid depletion of autoimmune disease-causing IgG autoantibodies.

argenx reports positive topline results from Phase 2 proof-of-concept trial of ARGX-113  

Top-line Results

• Primary endpoint analysis revealed ARGX-113 to be well tolerated in all patients, with most adverse events characterized as mild and deemed unrelated to the study drug. No serious or severe AEs were reported. The observed tolerability profile is consistent with the Phase 1 healthy volunteer study.
• The secondary endpoint measures relating to efficacy showed ARGX-113 treatment resulted in rapid onset of action and strong clinical improvement over placebo during the entire duration of the study.
  Specifically, co observed that:
  • 75% of patients treated with ARGX-113 had a clinically meaningful and statistically significant improvement in MG-ADL scores (at least a 2-point reduction from baseline) for a period of at least 6 consecutive weeks versus 25% of patients on placebo.
  • Clinical benefit in the ARGX-113 treatment group maximized as of 1 week after the administration of the last dose, achieving statistical significance over the placebo group on the MG-ADL score. Increasing differentiation was observed between the
  • ARGX-113 treatment group versus placebo with increasing MG-ADL thresholds.
  • Patients in the treatment arm showed rapid disease improvement, with clear separation from placebo 1 week after the first infusion.
  • All patients in the treatment arm showed a rapid and deep reduction of their total IgG levels and disease improvement was found to correlate with reduction in pathogenic IgG levels.
  • ARGX-113 demonstrated strong clinical improvement over placebo as measured by all four predefined clinical efficacy scales - MG-ADL, QMG, MGC and MG-QoL15.