Vyvgart may be safe, effective in treatment-resistant MG: Review
Patients saw symptoms ease, ability to perform daily activities improve
People with refractory myasthenia gravis (MG) who fail to respond to several treatments may be effectively treated with Vyvgart (efgartigimod alfa-fcab), regardless of the type of self-reactive antibodies they carry.
That’s according to a systematic review and meta-analysis, which showed that patients treated with Vyvgart saw their symptoms ease and their ability to perform daily activities improve. The treatment was also well-tolerated, with few serious adverse events reported.
“Our study demonstrates that [Vyvgart] is highly effective and well-tolerated in patients with refractory MG. These findings suggest that [Vyvgart] is a promising drug for the treatment of MG,” researchers wrote.
The study, “The efficacy and safety of efgartigimod for refractory myasthenia gravis: a systematic review and meta-analysis,” was published in the European Journal of Medical Research.
Vyvgart works to block key protein
MG is caused by self-reactive antibodies targeting proteins involved in nerve-muscle communication, most commonly acetylcholine receptors (AChRs). This leads to symptoms of muscle weakness and fatigue. The self-reactive antibodies driving MG belong to the IgG class of antibodies.
Vyvgart is approved to treat people with generalized MG who are positive for anti-AChR antibodies. It works to block the neonatal Fc receptor, a protein that normally helps stabilize IgG antibodies circulating in the bloodstream — including those driving MG — and prevent their destruction. Through this mechanism, the therapy is expected to accelerate the rate at which self-reactive antibodies are broken down, lowering their levels and easing MG symptoms.
In this study, researchers conducted a systematic review and meta-analysis of studies analyzing the efficacy and safety of Vyvgart in real-world settings. The analysis comprised 10 studies involving a total of 308 patients, all of whom were considered either unresponsive to MG treatments or in whom the disease was not well controlled with medication.
Participants had a mean age ranging from 45.9 years to 65.6 years and were mainly women (64.9%). Vyvgart was initiated at a 10 mg/kg dose via intravenous, or into-the-vein, injection once weekly for at least one four-week cycle.
‘Patients have shown improvements in clinical symptoms and quality of life’
Pooled data from the studies revealed a response rate to the first treatment cycle of 78%, which is “a favorable efficacy rate for [Vyvgart] treatment,” according to the researchers. Response rate was defined as a reduction of the MG Activities of Daily Living (MG-ADL) score of at least two points over four weeks, which indicates meaningful improvement. MG-ADL is a standard measure of MG severity that is designed to evaluate the impact of symptoms on a patient’s daily life.
A subgroup analysis based on antibody type revealed a response rate of 79.2% in the five studies where all participants had anti-AChR antibodies. In the other studies that did not differentiate antibody types, the response rate was 76.2%.
Based on its positive efficacy and safety, patients with refractory MG of all antibody subtypes ought to attempt to select [Vyvgart].
The pooled incidence of adverse events was 38% across nine studies. These events mainly included upper respiratory and urinary tract infections (30 infections; pooled incidence of 7%) and headaches (35 events; pooled incidence of 7%).
Fifty cases of mild adverse events, including diarrhea, nausea, sore lips, stiffness, and neck rash, had a pooled incidence of 16%. Serious adverse events, including worsening MG or MG crisis, rectal cancer, and depression, had a pooled incidence of 1%.
“Based on its positive efficacy and safety, patients with refractory MG of all antibody subtypes ought to attempt to select [Vyvgart],” the researchers wrote. “Patients have shown improvements in clinical symptoms and quality of life,” they wrote, noting that “compared with other immuno-suppressants, the adverse reactions associated with [Vyvgart] are more tolerable.”
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