SUMMARY

• The company cannot recommend any practices, procedures, or usage that deviate from the approved labeling.
• In a 24-week phase 3, randomized, double-blind, placebo (PBO)-controlled trial in adult patients with generalized myasthenia gravis (gMG), effect on fatigue was measured by the Quality of Life in Neurological Disorders (Neuro-QoL) assessment tool.^1,2 
• The change from baseline (CFB) in Neuro-QoL Fatigue scores was numerically greater in patients receiving IMAAVY + standard of care (SOC) vs those receiving PBO + SOC, with a least square (LS) mean difference of -4.4 (95% confidence interval [CI]: -8.88 to 0.09; P=0.055) by week 2 and -4.3 (95% CI: -9.16 to 0.62; P=0.087) at week 24.¹ 
• In the IMAAVY group, 6.2% more patients reached Neuro-QoL Fatigue meaningful within person improvement (MWPI) compared to the PBO group at week 24 (odds ratio [OR], 1.34; 95% CI: 0.66–2.75; P=0.424).¹ 
  • Those receiving IMAAVY were more likely to have sustained Neuro-QoL Fatigue MWPI for ≥8, 12, 16, and 20 weeks vs PBO (P<0.05).¹ 
• In patients with more severe baseline gMG, a numerically greater mean improvement in Neuro-QoL Fatigue scores was observed with IMAAVY + SOC vs PBO + SOC at Week 24.¹ 
• A greater proportion of patients receiving IMAAVY reported a fatigue severity of “none” and a change from baseline in fatigue as “much better” or “moderately better” at week 24 compared to those receiving PBO, based on the Patient Global Impression of Severity (PGIS) and the Patient Global Impression of Change (PGIC) scales, respectively.³

CLINICAL DATA

VIVACITY-MG3

Vissing et al (2025)¹ and Cortés Vicente et al (2025)³ utilized the Neuro-QoL Fatigue, PGIS-Fatigue, and PGIC-Fatigue scales to assess patient-reported fatigue, fatigue severity, and change in fatigue in patients enrolled in the VIVACITY-MG3 study.

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.⁴ 
• 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.^4,5 
  • The safety analysis population included all randomized patients who received ≥1 dose (partial or complete) of any study treatment in the double-blind phase.
  • The efficacy analysis population included all patients from the safety analysis set who had anti-AChR, anti-MuSK or anti-LRP4 antibody positive gMG.
• 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 (OLE) phase, and a safety follow-up at 8 weeks after the last infusion.² 
  • 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.^2,4 
• A secondary outcome measure of the study was the average CFB in the Neuro-QoL Fatigue total score over weeks 22 and 24. In addition, the following was evaluated:² 
  • The proportion of patients with MWPI at week 24, defined as a ≥6.7-point improvement from baseline.^1,6 
  • The change in Neuro-QoL Fatigue scores including in patients with more severe baseline disease, defined as a Myasthenia Gravis–Activities of Daily Living (MG–ADL) score of >9 and a Quantitative Myasthenia Gravis (QMG) score of >15.¹
• An exploratory outcome measure was PGIS and PGIC frequency distribution of responses over time in the double-blind phase.² 
  • PGIS-Fatigue assesses fatigue severity, with a scoring range of 1 (none) to 5 (very severe).³ 
  • PGIC-Fatigue assesses change from baseline in fatigue severity, with a scoring range of 1 (much better) to 7 (much worse).³ 

Results

Neuro-QoL Fatigue

• A total of 196 patients (IMAAVY, n=98; PBO, n=98) were included in the full safety analysis set.⁴ 
  • Of those, 153 patients were seropositive and were included in the primary efficacy analysis set, with 77 patients randomized to IMAAVY and 76 randomized to PBO.
• By week 2, the CFB in Neuro-QoL Fatigue scores was numerically greater in patients receiving IMAAVY + SOC compared to PBO + SOC (LS mean difference of -4.4 [95% CI: -8.88 to 0.09]; P=0.055).¹ 
  • At week 24, a similar trend was observed between the treatment groups (LS mean difference of -4.3 [95% CI: -9.16 to 0.62]; P=0.087). For more details, see Figure: CFB in Neuro-QoL Fatigue Scores.

• At Week 24, 62.7% (42/67) of patients in the IMAAVY group met the Neuro-QoL Fatigue MWPI threshold compared to 56.5% (35/62) in the PBO group (difference, 6.2% [95% CI: -10.7 to 23.2]; OR, 1.34 [95% CI: 0.66–2.75], P=0.424).¹ 
• Patients in the IMAAVY group were more likely to achieve sustained Neuro-QoL Fatigue MWPI at weeks ≥8, ≥12, ≥16, and ≥20 (P<0.05). See Figure: Neuro-QoL Fatigue MWPI by Duration.¹ 

• For effects on fatigue at week 12 and week 24 in patients with more severe baseline gMG, see Table: Mean CFB in Neuro-QoL Fatigue scores in patients with MG-ADL >9 and QMG >15.¹ 

PGIS/PGIC

• At week 24, 14.3% of patients in the IMAAVY + SOC group reported a PGIS response of “none” compared to 4.9% in the PBO + SOC group. For more details, see Table: PRO Scores per PGIS at Week 24.³ 
• At week 24, 33.9% of patients receiving IMAAVY reported fatigue as “much better”, versus 14.8% of patients receiving PBO. For additional information on PGIC response, see Figure: PRO Scores per PGIC at Week 24.³ 

Safety

• The proportion of patients who reported related AEs, per investigator assessment, was 29% in both the IMAAVY (28/98) and PBO (28/98) groups.⁴ 
• Any serious adverse events (SAEs) were reported in 9% (9/98) and 14% (14/98) of patients in the IMAAVY and PBO groups, respectively.⁴ 
• 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%).^4,7 

Literature Search

A literature search of MEDLINE^®, EMBASE^®, BIOSIS Previews^®, and DERWENT^® (and/or other resources, including internal/external databases) was conducted on 1 July 2025.