SHANGHAI, China / CAMBRIDGE, Massachusetts / AMSTERDAM, Netherlands — August 17, 2026
Zai Lab Limited and argenx announced positive topline results from the Phase 3 ALKIVIA trial evaluating VYVGART Hytrulo (efgartigimod alfa and hyaluronidase-qvfc) in adults with autoimmune myositis, marking a significant clinical development for patients with immune-mediated necrotizing myopathy (IMNM) and dermatomyositis (DM). The study met its primary endpoint, with efgartigimod demonstrating a statistically significant and clinically meaningful improvement in Total Improvement Score (TIS) at Week 52 compared with placebo. The results are particularly relevant to the development of targeted treatment approaches for autoimmune myositis, a disease spectrum characterized by chronic inflammation, progressive muscle weakness and, in some patients, skin and other systemic manifestations. The companies said the findings support the potential of FcRn-targeted therapy to address pathogenic IgG autoantibodies that contribute to disease activity..
ALKIVIA Achieves Primary Endpoint in Autoimmune Myositis
Zai Lab and argenx reported that the combined IMNM and DM population treated with efgartigimod achieved a mean TIS of 47.95 at Week 52, compared with 32.56 for placebo, representing a 15.4-point greater improvement and meeting the prespecified primary endpoint with p=0.0011. Importantly for the cGxP.wire audience, the treatment effect was observed early, with improvements over placebo emerging by Week 4 and remaining sustained throughout the 52-week treatment period, including during corticosteroid tapering. Prespecified analysis also showed a statistically significant improvement in the IMNM population, with efgartigimod producing a 14.8-point greater improvement than placebo and a p-value of 0.0048. IMNM is an important development area because patients with this subtype currently have no approved targeted therapy, highlighting the potential clinical significance of the ALKIVIA findings.
Targeted FcRn Approach Shows Sustained Treatment Benefit
The ALKIVIA findings provide further clinical evidence supporting FcRn inhibition as a potential treatment strategy in autoimmune myositis. Efgartigimod is designed to block the neonatal Fc receptor, thereby reducing circulating IgG autoantibodies that can contribute to autoimmune disease activity. Across the combined IMNM and DM population, all six core measures contributing to the TIS favored efgartigimod, covering areas including muscle strength, physical function and disease activity. In DM patients, improvements were also observed in skin disease activity. Although the DM subgroup showed a clinically meaningful 14.5-point improvement compared with placebo, statistical significance was not reached in this smaller cohort. The overall consistency of the findings across disease subtypes, together with the sustained treatment response, provides an important foundation for further regulatory and clinical development of VYVGART Hytrulo in autoimmune myositis. The companies stated that detailed results will be presented at a forthcoming medical meeting and shared with regulatory authorities.
Advertisement
Positive Phase 3 Data Strengthen Development Opportunity
The global randomized, double-blind, placebo-controlled ALKIVIA Phase 3 study enrolled 175 patients and evaluated weekly subcutaneous efgartigimod versus placebo, with a protocol-mandated corticosteroid taper. The broader ALKIVIA program enrolled 264 patients across autoimmune myositis subtypes, including IMNM, DM and polymyositis. The positive topline results strengthen the development case for efgartigimod in a disease area where treatment remains heavily dependent on corticosteroids and broad immunosuppressive therapies. For Zai Lab, participation in the global study supports its strategy to expand innovative therapies addressing significant unmet medical needs in China, while argenx continues to advance the broader potential of efgartigimod across autoimmune diseases. Under their existing collaboration, Zai Lab holds rights to develop and commercialize VYVGART and VYVGART Hytrulo in Greater China. The companies now expect to present comprehensive ALKIVIA data at an upcoming medical meeting, providing additional information on efficacy, safety and the potential regulatory pathway for this targeted treatment approach.
Source: Zai Lab press relese
