Argenx Advances Efgartigimod SC Research in Idiopathic Inflammatory Myopathies

argenx SE, a global leader in immunology focused on enhancing the lives of those with severe autoimmune conditions, revealed their commitment to advancing efgartigimod subcutaneous (SC) (efgartigimod alfa and hyaluronidase-qvfc) in the ongoing phase 2/3 ALKIVIA trial for adults with idiopathic inflammatory myopathies (IIM, also known as myositis), following a review of initial top-line data from the phase 2 segment. The ALKIVIA study will continue patient recruitment across three different myositis subtypes, which include immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and dermatomyositis (DM).

“Efgartigimod SC is showing significant promise for individuals enduring chronic autoimmune disorders,” expressed Luc Truyen, M.D., Ph.D., chief medical officer at argenx. “Idiopathic inflammatory myopathies are incapacitating conditions that lead to muscle weakness, impact several organs, and significantly affect patients’ quality of life, contributing to heightened morbidity and early mortality. We are eager to further the development of efgartigimod SC across all defined subtypes, allowing a detailed exploration of this targeted therapy’s potential for patients whose needs currently exceed existing treatments such as steroids, plasma-derived solutions, and broad immunosuppressants. Our gratitude goes to participants and researchers involved in the ALKIVIA study, as we aim to offer efgartigimod to myositis sufferers swiftly.”

The choice to advance clinical development of efgartigimod SC in the trio of myositis subtypes stems from positive safety and efficacy outcomes noted in the phase 2 part of the seamless phase 2/3 ALKIVIA study. Overall, the research achieved its primary goal, revealing a statistically significant treatment impact in average total improvement scores (TIS) at the 24-week mark and marked improvement across all six core TIS measurements, favoring efgartigimod SC over placebo. The safety and tolerability observed were consistent with prior clinical findings.

The ALKIVIA trial is a double-blind, placebo-controlled, multicenter, phase 2/3 operationally seamless study of efgartigimod SC for treating idiopathic inflammatory myopathies (IIM, or myositis) across three subtypes, including immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), and dermatomyositis (DM). It will include 240 patients and is split into two phases, with the phase 2 analysis occurring after the initial 90 patients completed the study, proceeding to phase 3 if promising results are observed in phase 2. The primary evaluation metric is the mean total improvement score (TIS) at the conclusion of treatment (24 weeks in phase 2 and 52 weeks in phase 3) in patients (IMNM, ASyS, DM) compared with placebo. Secondary evaluations cover response rates, time to response, response duration in TIS, as well as baseline change in individual TIS components, along with quality of life and functional metrics.

Idiopathic inflammatory myopathies (myositis) are rare autoimmune disorders involving muscle-specific or multi-organ impact, such as the skin, joints, lungs, gastrointestinal system, and heart. Myositis can be severely disabling and materially affects quality of life. Initially classified as either DM or polymyositis, new subtypes including IMNM and ASyS have emerged due to advances in understanding myositis pathology, such as discovering associated autoantibodies. A common feature is proximal muscle weakness. IMNM involves muscle cell necrosis leading to skeletal muscle weakness. ASyS is characterized by muscle inflammation, inflammatory arthritis, lung disease, hand thickening/cracking (‘mechanic’s hands’), and Raynaud’s phenomenon. DM is associated with muscle inflammation, skin anomalies like heliotrope rash, Gottron’s papules, and others.

Efgartigimod SC (efgartigimod alfa and hyaluronidase-qvfc) is a human IgG1 antibody fragment designed to curtail pathogenic immunoglobulin G (IgG) antibodies by binding to the neonatal Fc receptor (FcRn) and disrupting the IgG recycling process. It is the first globally approved FcRn blocker, marketed as Vyvgart Hytrulo in the USA and China for generalized myasthenia gravis (gMG) and chronic inflammatory demyelinating polyneuropathy (CIDP), as Vyvgart SC or Vyvdura (in Japan) for gMG elsewhere. Efgartigimod SC is presently under evaluation for over 15 severe autoimmune disorders where pathogenic IgGs play a role.

argenx is a prominent global immunology firm dedicated to uplifting lives impacted by severe autoimmune diseases. By forging partnerships with top academic experts via its Immunology Innovation Program (IIP), argenx strives to turn immunology breakthroughs into a comprehensive collection of pioneering antibody-based medications. argenx has developed and commercialized the first globally approved neonatal Fc receptor (FcRn) blocker across countries including the US, Japan, Israel, the EU, UK, China, and Canada.