argenx Advances Clinical Development of Efgartigimod SC in Idiopathic Inflammatory Myopathies

In This Article:

argenx SE
argenx SE


  • Phase 2 data establish proof-of-concept of efgartigimod SC in myositis

  • Enrollment to continue in Phase 3 across all three subtypes (IMNM, ASyS, DM) under evaluation in ALKIVIA

  • Potential for efgartigimod SC to be first targeted approach for myositis patients who have limited treatment options

November 20, 2024, 7:00 AM CET

Amsterdam, the Netherlands – argenx SE (Euronext & Nasdaq: ARGX), a global immunology company committed to improving the lives of people suffering from severe autoimmune diseases, today announced the decision to continue development of efgartigimod subcutaneous (SC) (efgartigimod alfa and hyaluronidase-qvfc) in the ongoing Phase 2/3 ALKIVIA study in adults with idiopathic inflammatory myopathies (IIM or myositis), following analysis of topline data from the Phase 2 portion of the study. ALKIVIA will continue to enroll patients across each of the three myositis subtypes in the study, including immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and dermatomyositis (DM).

“Efgartigimod SC continues to show its promise for patients suffering from chronic autoimmune diseases,” said Luc Truyen, M.D., Ph.D., Chief Medical Officer of argenx. “Idiopathic inflammatory myopathies are debilitating diseases that can cause muscle weakness, affect multiple organs, and have a severe impact on patients’ quality of life, including increased morbidity and early mortality. We are excited to continue the development of efgartigimod SC across all three subtypes, allowing us to explore the broad potential of this precision therapy for those whose needs remain unmet by current treatments like steroids, plasma-derived therapies, and broad immunosuppressants. We are grateful for the patients and investigators participating in the ALKIVIA study, and hope to bring efgartigimod to patients living with myositis as soon as possible.”

The decision to continue clinical development of efgartigimod SC in each of the three myositis subtypes is supported by the efficacy and safety results from the Phase 2 portion of the seamless Phase 2/3 ALKIVIA study. Overall, the study met its primary endpoint, demonstrating a statistically significant treatment effect in mean total improvement score (TIS) at Week 24, and showed improvement across all six core set measures of the TIS in favor of efgartigimod SC compared to placebo. The observed safety and tolerability profile was consistent to that demonstrated with other clinical trials.

ALKIVIA Study Design

The ALKIVIA study is a randomized, double-blind, placebo-controlled, multicenter, operationally seamless Phase 2/3 study of efgartigimod SC for the treatment of idiopathic inflammatory myopathies (IIM or myositis) across three subtypes, including immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and dermatomyositis (DM). The ALKIVIA study will enroll 240 patients in total and is being conducted in two phases, with an analysis of the Phase 2 portion of the clinical trial after the first 90 patients completed the study, followed by a Phase 3 portion if a signal is observed in the Phase 2 portion. The primary endpoint is the mean total improvement score (TIS) at the end of the treatment period (24 weeks in Phase 2 and 52 weeks in Phase 3) of all treated patients (IMNM, ASyS, DM) compared to placebo. Key secondary endpoints include response rates at the end of treatment, time to response, and duration of response in TIS, as well as change from baseline in individual TIS components. Other secondary endpoints include quality of life and other functional scores.