Real-world study finds Vyvgart often effective in gMG, but responses vary
Results highlight variable responses and limited durability in some patients
Written by |
In real-world practice, Vyvgart (efgartigimod alfa) is generally well tolerated and often effective for adults with generalized myasthenia gravis (gMG) who are positive for antibodies against the acetylcholine receptor (AChR) protein, a study showed.
However, responses vary across patients and are often not durable, data showed.
“These findings highlight the heterogeneity [variability] of therapeutic outcomes and emphasize the importance of individualized treatment strategies,” the researchers wrote.
Real-world study examines Vyvgart response patterns in gMG
The study, “Heterogeneous response to efgartigimod in real-world experience with myasthenia gravis: Predictors and treatment strategies,” was published in Neurotherapeutics.
In gMG, the immune system produces self-reactive antibodies that disrupt communication between nerves and muscles, causing symptoms such as generalized muscle weakness.
Vyvgart works by suppressing the activity of a protein that normally helps prevent circulating antibodies from being broken down. This is expected to accelerate the breakdown of antibodies, including those that drive MG.
Infused into the bloodstream once weekly in four-week cycles, the therapy is approved for adults with gMG who are positive for self-reactive antibodies against AChR — the most common type of MG-driving antibody. However, there are still limited real-world data about how well it works over long periods.
Here, a team of researchers in Israel reviewed the medical records of 46 adults (24 women, 22 men) with AChR-antibody positive gMG to understand how they responded to Vyvgart over time, whether the treatment reduced the need for standard corticosteroids, and which patients benefited the most.
Corticosteroids are a type of anti-inflammatory and immunosuppressive treatment commonly used in gMG, but long-term use can cause serious side effects.
Patients received a total of 193 treatment cycles, with an average of 4.3 cycles per patient and 9.8 weeks between cycles.
Most patients improved, but responses were not consistent
After the first Vyvgart cycle, most patients (86.9%) experienced a drop of at least two points on the validated MG Activities of Daily Living (MG-ADL) scale, a change considered clinically meaningful. More than half (58.7%) saw their score drop by at least four points, and nearly one-quarter by six or more points.
The MG-ADL scale measures how much the disease affects everyday tasks such as speaking, swallowing, and breathing, with higher scores indicating a greater impact.
Nearly half of patients (43.5%) reached minimal symptom expression, defined as a score of no more than one point on the MG-ADL scale, after one cycle. Overall, 50% of participants achieved this outcome at some point during follow-up, and nearly one-third (30.4%) “demonstrated a recurrent pattern of achieving [minimal symptom expression] after each treatment cycle,” the team wrote.
At the last follow-up, most patients (78.3%) maintained an improvement by at least two points on the MG-ADL scale, and more than half (56.4%) maintained a score reduction of four or more points. However, responses were not consistent for everyone.
Among the 39 participants who were followed for at least one year, 20 (51.3%) discontinued treatment with Vyvgart. Of these, 11 stopped because the therapy did not work well enough after at least two consecutive cycles, five stopped after reaching sustained maximal improvement, three stopped due to a waning response, and one stopped because of an adverse event.
Vyvgart use linked to reduced steroid use in some patients
Among the 29 patients taking the corticosteroid prednisone at the start of Vyvgart, more than half (58.6%) significantly reduced their average daily dose from 30.9 mg to 16.8 mg. Four patients (13.8%) stopped prednisone entirely. Participants who lived with the disease for a shorter time were significantly more likely to reduce their dose.
Some patients also used Vyvgart as a bridging medication, a temporary treatment used while waiting for another slower-acting therapy to take effect. Vyvgart was successfully used as bridging therapy in five patients, particularly those taking azathioprine or mycophenolate, medications that suppress the immune system but act more slowly.
Adverse events were reported in 10 patients (21.7%) but were usually mild. Those suspected as treatment-related included headache, upper respiratory tract infections, fatigue, chest discomfort, dizziness, bronchitis (inflammation of the airways in the lungs), and nausea. One patient discontinued treatment due to bronchitis that was suspected to be related to Vyvgart.
Overall, Vyvgart was generally well tolerated and often effective, but the benefits were uneven and sometimes not durable. “These findings support its integration into individualized treatment strategies and highlight the need for larger, [follow-up] studies to further define predictors of response and optimize long-term management,” the researchers concluded.
Leave a comment
Fill in the required fields to post. Your email address will not be published.