Approved infusion therapy offers fast relief from severe MG flares
Small study suggests Vyvgart may be effective alternative to standard treatments
Written by |
- As small study found that the infusion therapy Vyvgart offers rapid, sustained symptom relief for severe flares in people with myasthenia gravis.
- While the data are limited, the researchers say the approved MG medication may work better than standard treatments for exacerbations.
- Use of Vyvgart also allowed many participants given corticosteroids as a flare treatment to reduce their dosages of those meds, the data show.
Vyvgart (efgartigimod alfa-fcab), an approved treatment for myasthenia gravis (MG), can quickly and safely ease symptoms in people with the rare neuromuscular disease who are experiencing severe flare-ups, a new study suggests.
Although the study was limited to a small number of patients, the researchers said the data show that Vyvgart “produced rapid, clinically meaningful improvement in severe MG exacerbations without safety concerns.” According to the team, these findings position the infusion therapy as a potential alternative to standard approaches to manage serious MG flares, or exacerbations in which symptoms suddenly worsen.
The researchers noted that treatments now in use “have short-lived efficacy, and … may not be readily available.”
The study, “Prospective study of efgartigimod in severe myasthenia gravis exacerbations requiring ventilatory or enteral support,” was published in the Journal of Neuromuscular Diseases. The work was funded by Argenx, the company that sells Vyvgart. The study was conducted at a single center in Israel.
An autoimmune disorder, MG is caused by self-reactive antibodies that block signals from nerve to muscle cells, resulting in symptoms such as muscle weakness and fatigue.
Patients may experience flares, and in severe cases, these exacerbations can cause difficulty breathing and swallowing, necessitating interventions that include ventilation and feeding tubes.
Vyvgart, administered directly into the bloodstream, is approved in the U.S. for treating adults with generalized myasthenia gravis, or gMG, the disease’s most common and severe type. It works by blocking neonatal Fc receptor (FcRn), a protein that stabilizes antibodies in the blood. By suppressing FcRn, the therapy helps decrease levels of MG-driving antibodies.
Treatments for MG flares have short-lived effectiveness
The standard treatments for MG exacerbations are plasma exchange, a blood-cleaning procedure, or intravenous immunoglobulin (IVIg), which involves the delivery of healthy antibodies to suppress autoimmune responses. While both can rapidly ease symptoms, the researchers noted that their effects are not usually long-lasting. Moreover, these treatments, specifically plasma exchange or plasmapheresis, may not be accessible to all patients.
“The need for other therapeutic modalities for MG crisis is a recognized unmet need,” the researchers wrote.
Now, a team led by researchers at Technion-Israel Institute of Technology conducted a Phase 4 study (NCT06688253) to test whether Vyvgart might be a useful tool to help control severe MG flares. A Phase 4 study, done after a drug is approved for use, is typically conducted to see how a treatment works in daily life.
This study involved 16 people, evenly split by sex, who were experiencing MG flares severe enough to require ventilation and/or tube feeding. All were treated with Vyvgart at a single Israeli hospital. Their mean age was 58.5 years.
Each received four weekly infusions of Vyvgart. Some were additionally given other immunosuppressive medicines, such as corticosteroids, which are widely used to reduce inflammation in MG.
To assess treatment response, the researchers looked at two standardized measures of disease severity: a patient-rated assessment called the MG Activities of Daily Living scale (MG-ADL), and a physician-rated tool called the Quantitative Myasthenia Gravis score (QMG).
Improvements with Vyvgart still seen at 8-week mark
The results showed that scores on both measures dropped, indicating improvement, within the first week of starting Vyvgart. After one month on the therapy, 75% of participants reported clinically meaningful score reductions in MG-ADL, the data showed.
A similar proportion showed either a stabilization or further reduction in their MG-ADL scores a month after treatment was completed, “indicating sustained efficacy after four weekly infusions,” the researchers wrote.
Importantly, the team noted that most participants (83%) who achieved clinically meaningful reductions in MG-ADL scores at four weeks maintained their response at eight weeks, showing continuing benefit.
Quality of life, as assessed with the MG Quality of Life 15-revised, improved in nine participants (56%), and these gains were significantly associated with changes in MG-ADL and QMG scores, the data showed.
Overall, the benefits with Vyvgart treatment were rapid and clinically meaningful, the researchers noted, adding that “efficacy was observed across patients with [variable] demographic characteristics and disease manifestations,” including in patients who had or had not undergone thymectomy. That surgical procedure is the removal of the thymus, a gland that’s part of the immune system and is thought to contribute to MG.
Collectively, these findings position [treatment with Vyvgart] as a rapid, well-tolerated, and logistically straightforward alternative to plasma exchange or IVIg, addressing a long-standing need for additional therapeutic approaches in the management of [serious MG flares].
Additionally, the researchers noted that half of the participants given corticosteroids during the disease flare were able to reduce the dose or discontinue these medications entirely at week eight. This is noteworthy because long-term corticosteroid treatment frequently causes serious side effects.
Safety data showed Vyvgart was tolerated well overall. Adverse events were reported in 56% of participants; almost all were nonserious. The only exception was one patient who experienced a second MG flare secondary to a viral lung infection about a month after the initial flare.
“No new safety findings were detected following the use of [Vyvgart] in the setting of impending or [serious MG flare],” the researchers wrote. “Collectively, these findings position FcRn blockade as a rapid, well-tolerated, and logistically straightforward alternative to plasma exchange or IVIg, addressing a long-standing need for additional therapeutic approaches in the management of [serious MG flares].”
Still, because the study was limited to a small number of patients at one center, the findings should be “interpreted as preliminary, signal-generating evidence supporting the feasibility and safety of [Vyvgart] in this setting; [an appropriately-controlled] trial is required to establish treatment-specific efficacy,” the team concluded.
Leave a comment
Fill in the required fields to post. Your email address will not be published.