SUMMARY

• The company cannot recommend any practices, procedures, or usage of IMAAVY that deviate from the approved labeling.
• In the overall VIVACITY-MG3 efficacy analysis population at week 24, patients receiving IMAAVY + standard of care (SOC) showed greater improvement in ocular Myasthenia Gravis-Activities of Daily Living (MG-ADL) scores vs placebo (PBO) + SOC¹:
  • The odds ratio (OR) of achieving a ≥1-point improvement was 1.603 for the double vision MG-ADL item (95% confidence interval [CI]: 0.905-2.841) and 1.843 for the eyelid droop MG-ADL item (95% CI: 1.055-3.217).
  • The OR of achieving a ≥2-point improvement in the overall MG-ADL-ocular domain was 2.88 (95% CI: 1.526-5.436).
• In the moderate-to-severe ocular manifestation (MSOM) population of the VIVACITY-MG3 trial, IMAAVY showed significantly greater mean changes from baseline vs PBO in MG-ADL-total scores (difference [standard error, SE], -1.35 [0.68]; P=0.025) and
  MG-ADL-ocular scores (difference, -0.5; P=0.046).²
  • The odds of achieving a meaningful within-person improvement (MWPI) in the ocular domain were also significantly higher with IMAAVY vs PBO (51% vs 24%; OR, 3.23; 95% CI: 1.30-8.07).

CLINICAL DATA

VIVACITY-MG3

Farmakidis et al (2025)¹ conducted a post-hoc analysis of VIVACITY-MG3 to evaluate if changes in MG-ADL-total score with IMAAVY + SOC vs PBO + SOC were driven by individual items, domains, or distinct muscle function groups. Caleys et al (2025)² conducted a post-hoc analysis of VIVACITY-MG3 to evaluate the efficacy of IMAAVY vs PBO in a subgroup of patients with generalized myasthenia gravis (gMG) and MSOM.

Study Design/Methods

• The VIVACITY-MG3 study evaluated the efficacy and safety of IMAAVY in adults with gMG in a phase 3, randomized, multicenter, double-blind, PBO-controlled study.³
• Patients (≥18 years of age) with anti- acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or low-density lipoprotein receptor 4 (LRP4) antibody-positive or seronegative (in all countries except France) gMG (Myasthenia Gravis Foundation of America [MGFA] class IIa-IVb) were included in the study.³
  • Eligible patients had MG-ADL scores of ≥6 at both screening and baseline.²
  • The safety analysis population included all randomized patients who received ≥1 dose (partial or complete) of any study treatment in the double-blind phase.³
  • The efficacy analysis population included all patients from the safety analysis set who had anti-AChR, anti-MuSK or anti-LRP4 antibody positive gMG.³
• The study consisted of a ≤4-week screening phase, followed by a 24-week, double-blind, PBO-controlled treatment phase, a variable-duration, open-label extension phase, and a safety follow-up at 8 weeks after the last infusion.³
  • Patients who withdrew or discontinued after receiving any amount of the study intervention were required to complete a safety follow-up assessment at 8 weeks after the last dose.
• Eligible patients were randomized (1:1) to receive either a loading dose of intravenous IMAAVY 30 mg/kg at week 0, followed by 15 mg/kg every 2 weeks (Q2W) or matching PBO through week 24 in addition to SOC therapy.³
• The MG-ADL scale includes two items in the ocular domain (double vision and eyelid droop), each scored from 0 to 3 to assess eye-related symptoms in myasthenia gravis (0: normal; 1: occurs, but not daily; 2: daily, but not constant; 3: constant).¹
• In the Farmakidis et al post-hoc analysis, mean change from baseline in the ocular
  MG-ADL domain and change of ≥1-point on MG-ADL items were evaluated.¹ 
• In the Caleys et al post-hoc analysis, the MSOM population was defined as patients with a baseline score of ≥2 points on either the diplopia or ptosis items of the MG-ADL scale.²
  • The endpoints assessed were the mean change from baseline to week 24 in MG-ADL-ocular scores and MG-ADL-total scores.²

Results

MG-ADL Item Outcomes (Ocular Domain)

• For baseline MG-ADL-ocular domain item score distributions between the IMAAVY + SOC and PBO + SOC groups,¹ see Table: Baseline MG-ADL Item Score Distribution (Ocular Domain).

• At week 24, patients receiving IMAAVY + SOC were more likely to achieve a ≥1-point improvement in ocular MG-ADL items compared to PBO + SOC¹:
  • Double vision: OR, 1.603 (95% CI: 0.905-2.841)
  • Eyelid droop: OR, 1.843 (95% CI: 1.055-3.217)
• At week 24, patients receiving IMAAVY + SOC showed numerically greater improvement in the ocular MG-ADL domain, with a mean change from baseline of -1.3 vs -0.6 (P=0.054), and a significantly higher likelihood of achieving a ≥2-point improvement in this domain (OR, 2.88; 95% CI: 1.526-5.436) compared to PBO + SOC.¹

Clinical Outcomes in MSOM Subgroup

• At baseline, patients in the MSOM subgroup receiving IMAAVY (n=54) and PBO (n=51) were comparable in mean age, body mass index, and mean (standard deviation [SD]) MG-ADL-ocular and MG-ADL-total scores.² See Table: Baseline and Demographics.

• At week 24, the change from baseline least-square (LS) mean difference in MG-ADL-total scores was significantly greater with IMAAVY vs PBO,² see Table: Change from Baseline in MG-ADL- Total and Ocular Scores at Week 24.

• At week 24, a significantly greater proportion of patients receiving IMAAVY achieved MWPI in the MG-ADL-ocular domain vs PBO (51% vs 24%; OR, 3.23; 95% CI: 1.30-8.07).²

Safety

• The proportion of patients who reported related adverse events (AEs), per investigator assessment, was 29% in both the IMAAVY (28/98) and PBO (28/98) groups.³
• Any serious adverse events were reported in 9% (9/98) and 14% (14/98) of patients in the IMAAVY and PBO groups, respectively.³
• The most common AEs occurring in ≥10% of patients in the IMAAVY group compared to the PBO group were coronavirus disease 2019 (COVID-19)-associated AEs (15% vs 12%), headache (14% vs 17%), muscle spasms (12% vs 3%), myasthenia gravis (12% vs 12%), and peripheral edema (12% vs 2%).^3,4

Literature Search

A literature search of MEDLINE^®, EMBASE^®, BIOSIS Previews^®, and DERWENT^® (and/or other resources, including internal/external databases) was conducted on 23 July 2025.