argenx presents Phase 3 ALKIVIA data showing efgartigimod benefits in autoimmune myositis
- Phase 3 ALKIVIA met its primary endpoint: efgartigimod produced a 15.4‑point greater mean Total Improvement Score (TIS) versus placebo at Week 52 (47.95 vs 32.56; p=0.0011).
- Clinical improvements were evident by Week 4 and sustained through 52 weeks, despite a protocol‑mandated corticosteroid taper.
- A higher proportion of IMNM and DM patients treated with efgartigimod reached TIS ≥40, and median time to TIS ≥40 was shorter versus placebo.
- Efgartigimod (VYVGART Hytrulo) was well tolerated; the safety profile was consistent with prior studies and its known profile.
Key results
The Phase 3 ALKIVIA study met its primary endpoint: efgartigimod produced a 15.4‑point greater mean Total Improvement Score (TIS) versus placebo at Week 52 in the combined IMNM and dermatomyositis (DM) population (47.95 vs 32.56; p=0.0011). Improvements were observed as early as Week 4 and were sustained through 52 weeks, including during a protocol‑mandated corticosteroid taper. A greater proportion of IMNM and DM patients reached TIS ≥40 and median time to TIS ≥40 was shorter with efgartigimod versus placebo.
Study design
ALKIVIA was a global, randomized, double‑blind, placebo‑controlled Phase 2/3 trial across immune‑mediated necrotizing myopathy (IMNM), DM and polymyositis (PM). The program randomized 265 patients; 175 received treatment in the Phase 3 portion. Participants on background therapy were randomized 1:1 to weekly subcutaneous efgartigimod PH20 SC (efgartigimod alfa with rHuPH20) or matched placebo. TIS (0–100), an ACR/EULAR‑validated composite, was the primary endpoint at 52 weeks.
Safety and mechanism
Efgartigimod is an FcRn blocker that reduces circulating IgG autoantibodies. In ALKIVIA it was well tolerated and its observed safety profile aligned with prior efgartigimod studies.
Presentation details
The ALKIVIA results will be presented as a late‑breaking oral (LB24) at ACR Convergence 2026 by lead author Dr Rohit Aggarwal on November 11, 9:15–9:30 a.m. ET.
Source: argenx