SUMMARY

• Please refer to local labeling for relevant information on IMAAVY and occurrence of infections.
• In a 24-week, phase 3, randomized, double-blind, placebo (PBO)-controlled trial (VIVACITY-MG3), 3% (3/98) of adult patients receiving IMAAVY reported severe infection or infection requiring invasive treatment, compared to 4.1% (4/98) of patients receiving PBO.¹
  • Infections occurred in 43% of patients in the IMAAVY group, and in 43% of patients in the PBO group.¹ 
  • There were 3 cases of herpes zoster in the IMAAVY arm during the double-blind phase, compared to no cases in the PBO arm.² 
• In the ongoing VIVACITY-MG3 open-label extension (OLE; safety analysis set, n=176), infection and infestations occurred in 125 patients in the combined IMAAVY group during an average follow-up of 70.53 weeks.³ 
• In the VIVACITY-MG3 trial, including the double-blind and OLE periods through November 2024, there were 2 cases of Epstein-Barr virus (EBV) infection in the IMAAVY group, compared to no cases in the PBO group.⁴ 
• In a phase 2, randomized, double-blind, multicenter, PBO-controlled trial (VIVACITY-MG) in adult patients with generalized myasthenia gravis (gMG), 33.3% (18/54) of patients in the combined IMAAVY group reported infections as a treatment-emergent adverse event (TEAE) compared to 21.4% (3/14) of patients in the PBO group.⁵
• In an ongoing, phase 2/3, open-label, uncontrolled, clinical trial (Vibrance-mg) 14.3% of adolescent (12 to <18 years) patients receiving IMAAVY reported Coronavirus disease-2019 (COVID-19), bacterial vaginosis or an upper respiratory tract infection.⁶

PRESCRIBING INFORMATION

WARNINGS AND PRECAUTIONS

Infections

• IMAAVY may increase the risk of infection.
• In Study 1, 42 (43%) out of 98 patients treated with IMAAVY reported 71 events of infection. Across Study 1 (double blind period) and its extension study (open label-period), out of 186 patients treated with IMAAVY, 132 (71%) patients reported 360 events of infection. Serious infections were reported in 7% of patients treated with IMAAVY.⁷ 
• Delay IMAAVY administration in patients with an active infection until the infection is resolved. During treatment with IMAAVY, monitor for clinical signs and symptoms of infection. If serious infection occurs, administer appropriate treatment and consider withholding IMAAVY until the infection has resolved.⁷ 

Latent Viral Infections

• Patients treated with IMAAVY may be at an increased risk of activation of latent viral infections, such as herpes zoster. In the extension period of Study 1, there were 2 patients with serious adverse reactions related to EBV infection, and 1 of these patients had fatal complications. Patients who screened positive for hepatitis were excluded from Study 1. Follow standard vaccination guidelines.⁷

Immunization

• The safety of immunization with live vaccines and the immune response to vaccination during treatment with IMAAVY are unknown. Because IMAAVY causes a reduction in IgG levels, vaccination with live vaccines is not recommended during treatment with IMAAVY.⁷ 
• Evaluate the need to administer age-appropriate vaccines according to immunization guidelines before initiation of treatment with IMAAVY.⁷ 

ADVERSE REACTIONS

Clinical Trials Experience

• Infection-related adverse reactions reported in at least 5% of patients treated with IMAAVY, and more frequently than PBO, are summarized in Table: Infection-Related Adverse Reactions (≥ 5%) of Patients Treated with IMAAVY and More Frequently than in PBO in Study 1.⁷ 

Infections

• In Study 1 and its extension study, infections that occurred in patients treated with IMAAVY (n=186) included upper respiratory tract infection (46%), respiratory tract infection (28%; including pneumonia, bronchitis, COVID-19), urinary tract infection (15%), herpes (8%; including herpes simplex, herpes zoster, herpes zoster oticus), influenza (8%), oral infection (8%; including candidiasis and dental infections), and skin infection (7%; including cellulitis). Two (1%) cases of infections (cellulitis and urinary tract infection) led to discontinuation of IMAAVY.⁷ 

CLINICAL DATA

VIVACITY-MG3

Antozzi et al (2025)^1,8,9 evaluated the efficacy, safety, pharmacokinetics (PK) and pharmacodynamics (PD) 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.
  • 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 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.
  • 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 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 standard of care (SOC) therapy.
• Patients entering the OLE phase continued to receive IMAAVY 15 mg/kg Q2W in addition to SOC.

Results

Double-Blind Phase

• A total of 196 patients (IMAAVY, n=98; PBO, n=98) were included in the safety analysis set.¹ 
• The events/patient-years (P-Y) rate for infection and infestations was 1.64 and 1.14 in the IMAAVY and PBO arms, respectively.³ 
• For the occurrence of infections in adult patients treated with IMAAVY and PBO, see Table: Incidence of Infections.^1,8 
• Through week 24, 3% (3/98) of patients receiving IMAAVY and 4% (4/98) of patients receiving PBO reported severe infection or infection requiring invasive treatment.¹ 

• Through week 24, a total of 3 cases of herpes zoster were reported in the IMAAVY group, inclusive of two non-serious cases and one serious case. No events were reported in the PBO group.² 
  • The exposure-adjusted incidence rate per 100 P-Y for herpes zoster events was 6.92 and 0.00 in the IMAAVY and PBO arms, respectively. See Table: Incidence of Herpes Zoster.

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).³ 
• In the combined IMAAVY group, the events/P-Y rate for infection and infestations was 1.39.
  • A total of 330 events were reported in 125 patients during an average follow-up of 70.53 weeks (237.9 P-Y).³ 
• For adverse events (AEs) by preferred term, see Table: Infection-Related AEs by Preferred Term in ≥0.1 Events per P-Y.

Double-Blind and OLE Phases

• Through a cutoff date of 05 November 2024, a total of 2 cases of EBV-related terms were reported in the IMAAVY arm. No events were reported in the PBO group.⁴ 
  • There was one fatal case of EBV-associated hemophagocytic lymphohistiocytosis considered to be treatment-related. The death occurred on study day 224, 18 days after the last dose of study treatment.³ 
  • The exposure-adjusted incidence rate per 100 P-Y for EBV infections is 0.56 and 0.00 for IMAAVY and PBO, respectively. See Table: Incidence of EBV Infection or Hemophagocytic Lymphohistiocytosis.⁴ 

Pooled Analysis

In a pooled analysis of the double-blind, PBO-controlled periods across all indications in which IMAAVY has been studied (i.e., phase 2 and 3 clinical studies in gMG, Sjogren’s disease, rheumatoid arthritis and systemic lupus erythematosus), exposure-adjusted incidence rates per 100 P-Y for herpes zoster were 3.12 and 1.09 in the IMAAVY and PBO arms, respectively. See Table: Pooled Analysis: Incidence of Herpes Zoster in Phase 2/3 Studies.² 

Phase 2 VIVACITY-MG Study

Antozzi et al (2024)⁵ conducted a phase 2, randomized, multicenter, double-blind, PBO-controlled clinical trial to evaluate the safety, efficacy, PK, and 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 included a 4-week screening period, followed by an 8-week, double-blind treatment period. Posttreatment follow-up assessment was performed for a period of 8 weeks.
• 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) in addition to SOC therapy.

Results

• A total of 68 patients (IMAAVY, n=54; PBO, n=14) were randomized to receive treatment.
• In the combined IMAAVY group, 33.3% (18/54) of patients reported infections as a TEAE compared to 21.4% (3/14) of patients in the PBO group, with nasopharyngitis being the most common (see Table: Incidence of TEAE-Related Infections and Infestations in the IMAAVY Versus PBO Group).⁵ 

Phase 2/3 Vibrance-mg Study

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 gMG who have an insufficient response to ongoing SOC therapy.

Study Design/Methods

• Adolescent patients, all with anti-AChR antibody positive gMG, were included in the analysis.
• The study consists of a screening period of up to 4 weeks, then a 24-week, open-label, active treatment phase where patients will receive IMAAVY 30 mg/kg IV loading dose at week 0, followed by IMAAVY 15 mg/kg Q2W from week 2 to week 22 in addition to SOC therapy.

Results

• A total of 7 adolescents have been included in the study. The average duration of safety follow-up was 18.37 weeks. For the occurrence of infections in adolescents treated with IMAAVY, see Table: Occurrence of Infections in the Safety Analysis Set through Week 24.⁶ 

Literature Search

A literature search of MEDLINE^®, EMBASE^®, BIOSIS Previews^®, and DERWENT^® (and/or other resources, including internal/external databases) was conducted on 28 May 2025.