SUMMARY

• In a 24-week, phase 3, randomized, double-blind, placebo (PBO)-controlled trial in adult patients with generalized myasthenia gravis (gMG), headache was reported in 14% of patients in the IMAAVY + standard of care (SOC) group and in 17% of patients in the PBO + SOC group.¹
• In a phase 2, randomized, double-blind, PBO-controlled trial in adult patients with gMG, headache was reported in 11.1% of patients in the combined IMAAVY group and in 7.1% of patients in the PBO group through day 113.^2,3 
• In an ongoing open-label extension (OLE) phase, the events per patient-years (PY) rate for headache in the combined IMAAVY group (n=176) was 0.21, with 50 events reported in 29 patients during a median follow-up of 72 weeks.⁴ 
• In an ongoing, phase 2/3, open-label, uncontrolled clinical trial in adolescents (12 to <18 years of age), headache was reported in 14.3% of patients on IMAAVY treatment through week 24.^5,6

CLINICAL DATA

VIVACITY-MG3

Antozzi et al (2025)¹ evaluated the efficacy and safety of IMAAVY in adults with gMG in a phase 3, randomized, multicenter, double-blind, PBO-controlled study.

Study Design/Methods

• 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.^1,7
  • The safety analysis population included all randomized patients who received ≥1 dose (partial or complete) of any study treatment in the double-blind phase or of IMAAVY in the OLE phase.^1,4 
• The study consisted of a ≤4-week screening phase, followed by a 24-week, double-blind, PBO-controlled treatment phase, a variable-duration, OLE phase, and a safety follow-up at 8 weeks after the last infusion.^1,8 
  • 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.⁸ 
• Eligible patients were randomized (1:1) to receive a loading dose of intravenous (IV) 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.^1,8 
• Patients entering the OLE phase continued to receive IMAAVY 15 mg/kg Q2W in addition to SOC.^4,8 

Results

Double-blind Phase

• A total of 196 patients (IMAAVY, n=98; PBO, n=98) were included in the full analysis set.¹ 
• Headache was reported in 14% (14/98) of patients in the IMAAVY + SOC group and in 17% (17/98) of patients in the PBO + SOC group.¹ 

Ongoing OLE Phase

• A total of 176 patients were included in the safety analysis set with a median follow-up of 72 weeks (IMAAVY→IMAAVY, n=88; PBO→IMAAVY, n=88).⁴ 
• In the combined IMAAVY group (N=176), the events per PY rate for headache was 0.21, with 50 events reported in 29 patients.⁴ 

Phase 2 VIVACITY-MG Study

Antozzi et al (2024)² conducted a phase 2, randomized, multicenter, double-blind, PBO-controlled clinical trial to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of IMAAVY in adult patients with gMG who had an insufficient response to ongoing, stable SOC therapy.

Study Design/Methods

• Patients (≥18 years of age) with anti-AChR or anti-MuSK antibody-positive gMG (MGFA class II, III, or IVa) were included in the study.
• The study consisted of a 4-week screening period, followed by an 8-week, double-blind treatment period. Post treatment follow-up assessment was over a 8 week period.
• In addition to SOC therapy, eligible patients were randomized (1:1:1:1:1) to receive IV infusions of IMAAVY 5 mg/kg once every 4 weeks (Q4W), IMAAVY 30 mg/kg Q4W, IMAAVY 60 mg/kg single dose, IMAAVY 60 mg/kg Q2W, or PBO Q2W (5% dextrose in water).

Results

• A total of 68 patients (IMAAVY, n=54; PBO, n=14) were randomized to treatment.
• Through day 113, headache was reported as treatment-emergent adverse event in 11.1% (6/54) of patients in the combined IMAAVY group and in 7.1% (1/14) of patients in the PBO group.^2,3 
  • In patients treated with IMAAVY, headache was reported in 14.3% (2/14) of patients in 5 mg/kg Q4W group, 7.7% (1/13) of patients in the 30 mg/kg Q4W group, 15.4% (2/13) of patients in the 60 mg/kg single dose group and 7.1% (1/14) of patients in the 60 mg/kg Q2W group.

Vibrance-mg Study

Ramchandren et al (2022)^5,9 is evaluating the safety, efficacy, PK, and PD of IMAAVY in children and adolescents in ages 2 to <18 years with gMG who have an insufficient response to ongoing, stable SOC therapy in an ongoing, open-label, uncontrolled multicenter clinical trial.

Study Design/Methods

• Patients with anti-AChR or anti-MuSK antibody positive gMG (MGFA Class IIa-IVb) were included in the study.
• The study consists of a screening period of up to 4 weeks, followed by a 24-week open-label active treatment phase where adolescent (12 to <18 years of age) patients will receive IMAAVY 30 mg/kg IV loading dose at week 0 followed by 15 mg/kg Q2W from week 2 to 22 in addition to SOC. Patients will have the option to enroll in an long-term extension phase.
  • A safety follow-up assessment will be conducted 8 weeks after the last dose.

Results

Strober et al (2024)⁶ presented results through the active treatment phase (study day 1 through week 24) in adolescents (aged 12 to <18 years) with a clinical cutoff date of December 15, 2023.

• Seven adolescent patients, all with anti-AChR antibody positive gMG were included in the analysis.
• Headache was reported in 1 patient (14.3%) through week 24.

Literature Search

A literature search of MEDLINE^®, EMBASE^®, BIOSIS Previews^®, and DERWENT^® (and/or other resources, including internal/external databases) was conducted on 02 July 2025.