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argenx Source : argenx SE August 17 , 2026 01:00 ET argenx Announces Positive Topline Results from Phase 3 ALKIVIA Trial of Efgartigimod in Autoimmune Myositis • Study met primary endpoint of mean Total Improvement Score ( TIS ) at Week 52 in the combined study population of IMNM and DM patients ( p = 0.0011 ) • Patient improvements observed early and sustained throughout study ; consistent treatment effect across IMNM and DM • First Phase 3 study to show statistically significant and clinically meaningful improvements in disease activity in IMNM , a subtype with no approved therapy • argenx to host a conference call on August 17th at 2:30 PM CET / 8:30 AM ET August 17 , 2026 , 7:00 AM CET Amsterdam , the Netherlands argenx SE ( Euronext & Nasdaq : ARGX ) , a global immunology innovation company , today announced positive topline results from the ALKIVIA Phase 3 study evaluating VYVGART® Hytrulo ( efgartigimod alfa and hyaluronidase - qvfc ) in adults with autoimmune myositis . Study met its primary endpoint ( p = 0.0011 ) • In the combined immune - mediated necrotizing myopathy ( IMNM ) and dermatomyositis ( DM ) population , patients treated with efgartigimod demonstrated statistically significant and clinically meaningful 15.4 - point greater improvement in mean Total Improvement Score ( TIS ) at Week 52 versus placebo ( 47.95 vs 32.56 ) . Rapid and sustained treatment benefit • In the combined population , patients treated with efgartigimod consistently showed improvements over placebo starting at Week 4 that were statistically significant and sustained through the full year of treatment , even with steroid tapering . Magnitude of clinical improvement consistent across both IMNM and DM