A small but significant percentage of myasthenia gravis (MG) patients remain resistant to current therapies, which severely impacts on their quality of life and requires greater attention and more aggressive treatments, according to a recent opinion piece from a neurologist.
The article, “Refractory Myasthenia Gravis – Patient Burden and the Need for New Therapeutic Targets,” was published in the European Neurological Review.
Despite an increasing number of immune therapies available for myasthenia gravis, about 10 percent of patients remain refractory, or resistant, to treatments, typically showing either frequent clinical relapses once the therapy dose is decreased or developing severe side effects from immunotherapy.
Refractory disease, according to the Myasthenia Gravis Foundation of America, is defined as a “post-intervention status … unchanged or worse after corticosteroids and at least 2 other immunosuppressive agents, used in adequate doses for an adequate duration, with persistent symptoms or side effects that limit functioning, as defined by patient and physician.”
However, there’s no general consensus on this definition, since different countries have different guidelines or recommendations, or have no definition at all for refractory disease, according to Saiju Jacob, MD, consultant neurologist at the Queen Elizabeth Neuroscience Centre, University Hospitals of Birmingham in the U.K., who wrote the opinion piece.
“Patients may remain refractory for more than 10 years; they are often considered refractory until they respond to a therapy or become asymptomatic without therapeutic intervention,” he said.
Patients with refractory myasthenia gravis frequently experience acute exacerbations of their symptoms, including swallowing difficulties. If respiratory muscles are impaired, patients experience what’s called a myasthenic crisis — up to 20 percent of myasthenia gravis patients have impairments in their respiratory function, and are at risk of respiratory failure and the need for intubation and mechanical ventilation.
These patients suffer a significant decrease in their quality of life, Jacob says, driven mainly by weakness in the muscles, especially in the limbs, which limits their ability to perform daily activities, such as driving and taking the stairs.
Ultimately, the refractory nature of the disease contributes to a marked emotional burden, with patients facing the possibility of giving up their careers, contributing to their feelings of isolation and depression.
“A Danish study (330 patients) found that patients with MG had almost six times higher odds of unemployment and almost nine times higher odds of long-term sick leave 2 years after diagnosis, compared with the general population,” Jacob wrote.
He argues that a greater effort is required to help patients achieve their therapy goals, and special attention is needed for those with refractory disease.
“For such patients, there is a need for more aggressive treatment or treatment directed to the underlying pathogenesis of the disease in order to prevent life-threatening crises, restore muscular strength and improve quality of life,” he said.
Overall, “while refractory MG is not a major public health problem in terms of number of patients affected, it is a chronic problem with a major financial impact on the patients themselves and the care system. There is a need not only for more evidence-based therapies but also on other measures that might enhance quality of life in patients with MG,” he concludes.