In 2018, there were 152,798 diagnosed prevalent cases of myasthenia gravis (MG) across the seven major markets (7MM: the US, France, Germany, Italy, Spain, the UK and Japan).
Globally, the majority (28.23%) of MG cases were diagnosed in its mildest form, class I. However, in the US, the situation is much different. In the US, 39.13% of diagnosed prevalent cases of MG were diagnosed as class III, which is a slightly more severe form of the disease.
Figure 1 presents the diagnosed prevalent cases of MG by severity class in the US, Japan and five major European markets (5EU: France, Germany, Italy, Spain, and the UK), in 2018.
MG is a chronic autoimmune disease that affects the neuromuscular junctions in the human body by affecting the ability of acetylcholine to bind to its receptors at these junctions. The cause of this disease remains unknown, but how it acts has been well studied. Antibodies circulating in MG patients block or destroy the binding sites for acetylcholine, causing an inability for nerves to communicate with muscles.
The symptoms of MG range from mild muscle soreness to difficulty swallowing, and in its most severe form involves a total inability for muscles in the body to function as normal. The Myasthenia Gravis Foundation of America has set forth clinical guidelines for classifying the severity of the disease from class I to V, with higher grades associated with a more severe version of the condition. In the most severe form of MG, advanced medical intervention may be required.
In 2018, GlobalData epidemiologists forecast that the US would have more than 50% of diagnosed prevalent cases of MG classified as class III and IV, and that the 5EU would have less than 30% of diagnosed prevalent cases classified as class III or higher. This may be due to differences in the underlying disease pathology or differences in awareness and rapid diagnosis. Although numerous treatment options exist for MG, accurate classification is needed to ensure rapid and appropriate treatment.