argenx: efgartigimod raised TIS by 15.4 points over placebo in phase 3 ALKIVIA trial in myositis
In the phase 3 ALKIVIA trial, efgartigimod met its primary endpoint in patients with IMNM and dermatomyositis. At week 52 the TIS gain over placebo was 15.4 points, but the dermatomyositis subgroup alone was not significant.
On 7 November 2026, ad-hoc-news.de reported that the phase 3 ALKIVIA trial of efgartigimod (VYVGART Hytrulo) from the biopharmaceutical company argenx met its primary endpoint. The trial enrolled a combined population of patients with immune-mediated necrotizing myopathy (IMNM) and dermatomyositis (DM). At week 52, the Total Improvement Score (TIS) was 48.0 points with efgartigimod versus 32.6 points with placebo. This is an adjusted difference of +15.4 points in favor of treatment, with p=0.0011 ad-hoc-news.de
ad-hoc-news.dead-hoc-news.deOpen source ↗.
Results by subgroup: IMNM and dermatomyositis
In the IMNM subgroup, the TIS difference versus placebo was +14.8 points (45.1 vs. 30.2; p=0.0048), which is statistically significant. Muscle strength measured by the MMT-8 score improved by +5.4 points.
The report also states that the efgartigimod group showed a creatine kinase (CK) reduction that was 43.5 percentage points greater than placebo, and a CK grade decrease of -0.9. The share of patients with a TIS of at least 40 points was 22.0 percentage points higher than with placebo. Treated patients were twice as likely to maintain a response once achieved.
In the DM subgroup, the TIS difference was +14.5 points versus placebo (51.5 vs. 37.0). With p=0.1093, this result did not reach statistical significance ad-hoc-news.de
ad-hoc-news.dead-hoc-news.deOpen source ↗. The CDASI score, which assesses cutaneous disease activity, improved by +5.6 points in this group. The share of patients with a TIS of at least 40 points was 27.2 percentage points higher than in the control group.
Trial design, safety and regulatory plans
The ALKIVIA study includes 265 randomized patients diagnosed with IMNM, DM or polymyositis. The phase 3 part covered 175 patients who received weekly injections over 52 weeks. Efgartigimod was reported to be well tolerated, and its safety profile was in line with earlier studies by the company.
Based on these results, argenx is preparing its next regulatory steps. For IMNM, a indication for which the FDA has already granted the agent a special regulatory status, the company plans to submit a supplemental biologics license application (sBLA) by the end of 2026. A detailed presentation of the ALKIVIA phase 3 results is scheduled for 11 November 2026 at the ACR Convergence 2026 meeting.
