Cambridge, Mass.– Zai Lab and argenx announced positive topline results from the Phase 3 ALKIVIA trial evaluating VYVGART Hytrulo, or efgartigimod alfa and hyaluronidase-qvfc, in adults with autoimmune myositis.
The study met its primary endpoint in the combined population of patients with immune-mediated necrotizing myopathy, or IMNM, and dermatomyositis, or DM. Patients treated with efgartigimod showed a statistically significant and clinically meaningful 15.4-point greater improvement in mean Total Improvement Score at Week 52 compared with placebo, with scores of 47.95 versus 32.56.
Treatment benefits were observed as early as Week 4 and were sustained through the full year of treatment, including during steroid tapering, the companies said.
In a prespecified analysis of patients with IMNM, efgartigimod produced a 14.8-point greater improvement over placebo, with the primary endpoint reaching statistical significance. Among patients with DM, treatment resulted in a similar 14.5-point improvement over placebo, though the difference did not reach statistical significance in the smaller cohort.
The companies said all six measures contributing to the Total Improvement Score favored efgartigimod in both patient groups, including measures of muscle strength, physical function and disease activity. Improvements in skin disease activity were also observed among patients with DM.
Efgartigimod was generally well tolerated, with a safety profile consistent with previous studies and its known safety profile.
“The Phase 3 ALKIVIA results demonstrate a clinically meaningful and statistically significant treatment benefit in the overall study population, including a significant improvement in patients with IMNM, a subtype with no approved therapies,” said Rafael G. Amado, M.D., President, Head of Global Research and Development at Zai Lab. “For patients in China living with autoimmune myositis, these results offer hope for a new targeted treatment option that could meaningfully improve muscle strength, physical function and other manifestations of this debilitating disease.”
Luc Truyen, M.D., Ph.D., Chief Medical Officer at argenx, said patients with autoimmune myositis have historically relied on corticosteroids and broad immunosuppression, while those with IMNM have had no approved treatment option.
“The patient response to efgartigimod was durable and multidimensional: separation from placebo emerged early and held through a full year of treatment, with a treatment effect of comparable magnitude in IMNM and DM,” Truyen said.
Rohit Aggarwal, M.D., M.S., Professor of Medicine and Co-Director of the Myositis Center at the University of Pittsburgh and an ALKIVIA investigator, said the findings were particularly notable in IMNM, which he described as one of the most difficult forms of the disease to treat.
Detailed results from the ALKIVIA study are expected to be presented at an upcoming medical meeting.
Efgartigimod is also being evaluated as a potential treatment for other autoimmune rheumatologic diseases, including Sjögren’s disease and systemic sclerosis.
