Johnson & Johnson’s (J&J’s) Imaavy (nipocalimab-aahu) has shown continued benefit for two years in patients with generalised myasthenia gravis (gMG)
Patients were treated for 24 weeks in the Phase III Vivacity-MG3 and for 96 weeks in the ongoing open-label extension (OLE) study (NCT04951622), creating a total treatment time of 120 weeks. After the OLE period, there was an average sustained reduction in Myasthenia Gravis Activities of Daily Living (MG-ADL) of 6.47 points and a reduction of 5.97 points in quantitative myasthenia gravis (QMG).
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Half of patients achieved minimal symptom expression (MSE), and nearly one-third (32%) achieved sustained MSE for at least eight weeks on Imaavy. MSE is a key treatment goal defined as an MG-ADL score of 0 or 1.
There was a greater than 64% reduction in total immunoglobulin G (IgG), including pathogenic IgG autoantibodies, the underlying driver of disease.
Dr Constantine Farmakidis, associate professor of Neurology at the University of Kansas Medical Center, said: “For people living with gMG, consistent and durable symptom control is the central goal of treatment. These long-term results, now extending to beyond two years, provide further evidence that disease control, as initially observed in the Imaavy Phase III pivotal study, can be sustained, and add to the body of evidence that may help guide clinical decision-making.”
Data was presented at the American Academy of Neurology (AAN) 2026 Meeting in Chicago, Illinois.
gMG is a chronic, debilitating autoantibody disease characterised by loss of muscle function and severe muscle weakness.
Imaavy is an immunoselective therapy designed to substantially reduce IgG without additional detectable effects on other adaptive and innate immune functions. The drug gained US Food and Drug Administration (FDA) approval in April 2025 and later gained approval in the EU in December 2025.
GlobalData’s patient based annual forecast predicts sales of Imaavy to reach $310m in 2033.
Also at AAN, Argenx presented Phase III data of Vyvgart (efgartigimod alfa) in patients with gMG, while Cabaletta Bio announced positive results from the Phase I/II open-label, RESET-MG study of rese-cel (resecabtagene autoleucel).
This comes as the data analysis company predicts the MG market across the seven major markets (7MM: US, France, Germany, Italy, Spain, UK, and Japan) to grow to $10.5bn in 2034 compared with $6.1bn in 2024. According to GlobalData’s drugs database, there are eight DMTs currently marketed across the seven major pharmaceutical markets (7MM: US, France, Germany, Italy, Spain, UK, and Japan) for MG.
GlobalData is the parent company of Clinical Trials Arena.
