Vyvgart shows rapid benefits for generalized myasthenia gravis: Study
It may safely and effectively treat acute exacerbations, symptom worsening
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- Vyvgart rapidly and effectively treats acute exacerbations and worsening symptoms in generalized myasthenia gravis.
- It shows rapid onset, significant improvement after the first dose, and sustained response across patient groups.
- Vyvgart is well-tolerated and works by speeding the breakdown of disease-driving antibodies.
Treatment with Vyvgart (efgartigimod alfa) may safely and effectively treat acute exacerbations and symptom worsening in people with generalized myasthenia gravis (gMG), a real-world study in China shows.
The treatment demonstrated a rapid onset of action, with significant improvements seen after the first dose, as well as a high and sustained response rate, with most patients achieving a clinically meaningful response. Vyvgart treatment was effective across different patient subgroups.
“[Vyvgart] exhibits rapid and potential clinical efficacy in gMG patients experiencing acute exacerbations or disease progression, supporting its potential as a viable therapy for such patients,” researchers wrote.
The study, “Rapid efficacy of efgartigimod for generalized myasthenia gravis patients in acute exacerbations/worsening: multicenter real-world retrospective study,” was published in the Journal of Neurology.
Vyvgart blocks key protein to speed breakdown of antibodies
Myasthenia gravis (MG) is characterized by weakness and fatigue that can affect muscles involved in voluntary movements. In most cases, it is caused by self-reactive antibodies that target proteins involved in nerve-muscle communication, most often acetylcholine receptors (AChRs). Generalized MG is the most common and severe type of MG, affecting several muscle groups across the body.
People with gMG may experience acute exacerbations, when the disease symptoms suddenly worsen or new symptoms appear. Exacerbations may require urgent medical intervention to prevent progression to myasthenic crisis, when respiratory muscles become weak and lead to breathing difficulties.
Vyvgart is an approved therapy for adults with gMG who are positive for anti-AChR antibodies. Infused into the bloodstream once weekly in four-week cycles, it works by blocking a protein that helps prevent circulating antibodies from being broken down. This is expected to speed the breakdown of antibodies, including those that drive MG.
In addition to its rapid and efficient action, confirmed in clinical trials, Vyvgart is more accessible than conventional rescue therapies for acute exacerbations such as intravenous immunoglobulin (IVIG) and plasma exchange.
IVIG involves delivering a pool of antibodies from healthy donors, and plasma exchange is a blood-cleaning procedure; both are meant to neutralize or remove disease-driving antibodies.
Most participants experienced acute exacerbations
In this study, a team of Chinese researchers evaluated the safety and efficacy of Vyvgart as a potential rapid-acting treatment for gMG exacerbations.
They retrospectively analyzed data from 61 gMG patients who were experiencing episodes of acute exacerbation or symptom worsening and were treated with Vyvgart at nine centers across the country. Disease worsening was defined as a substantial increase in clinical manifestations or a dose increase of MG-related medication to maintain disease stability.
More than half of the participants (55.7%) were women, and their median age at treatment start was 56 years (range: 39-68 years). They had been living with gMG for a median of eight months, and most tested positive for anti-AChR antibodies.
Most participants (77.1%) experienced acute exacerbations, while 22.9% experienced worsening of disease. Before disease exacerbation or worsening, most were treated with acetylcholinesterase inhibitors (95.1%), corticosteroids (73.8%), and other immunosuppressive treatments (65.6%).
Among those with acute exacerbations, 36 (76.6%) had signs of impending myasthenic crisis, meaning they were at risk of evolving to a crisis. Those with such signs had more severe disease before the exacerbation, and more commonly had a thymoma, or a tumor in the thymus gland, compared with those without such signs (47.2% vs. 20%). Problems in the thymus are thought to contribute to the production of MG-driving antibodies.
Most patients showed clinically meaningful improvement after 1st dose
After acute exacerbation or worsening, all participants received one Vyvgart cycle and were followed for four weeks after the last treatment dose.
After the first dose, most patients (81.9%) experienced a clinically meaningful improvement, defined as a reduction of at least 2 points on the MG-Activities of Daily Living (MG-ADL) scale, which assesses MG’s functional impact on activities of daily living. Also, six people (9.8%) reached minimal manifestation status (MMS), or no symptoms.
Right after completing a Vyvgart cycle, 85.2% experienced clinically meaningful improvement, and 59.6% achieved MMS.
Response rates remained high about a month after completion of the treatment cycle. Treatment effects were seen regardless of age at disease onset, disease duration, presence of infections or thymoma, and treatment history.
Participants with more severe disease, a history of myasthenic crisis or thymoma, or signs of impending crisis exhibited a significantly more pronounced response to Vyvgart.
Still, “due to their significantly higher [initial] scores, patients with red flags still exhibited higher MG-ADL scores … [suggesting] that additional treatment cycles may be necessary to achieve the treatment goal,” the team wrote.
The treatment was well tolerated, with no reports of adverse events such as infections, allergic reactions, or infusion site reactions.
Overall, the study demonstrates that a single Vyvgart treatment cycle had a fast onset of action and treatment response, and led to clinical improvement across a broad range of MG patient populations.
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