Myasthenia gravis (MG) is an autoimmune and neuromuscular disease characterised by muscle weakness and fatigue. In the majority of patients, the disease is initially localised and limited to the eye muscles, causing drooping of the eyelid (ptosis) and double vision (diplopia). This weakness can give patients difficulty controlling eye and eyelid movement, facial expressions, chewing, and talking. In some cases, the disease progressively affects respiratory muscles. Currently, most of the first-line treatment options available for the treatment of MG are off-label symptomatic therapies, which are mainly used due to their affordability and accessibility. Generally, disease-modifying therapies (DMTs) are only being used in refractory patients who have been diagnosed with class II–V MG.
In July 2023, 82 high-prescribing neurologists from the seven major markets (7MM: US, France, Germany, Italy, Spain, UK, and Japan) were surveyed to identify current trends in the treatment of MG, including the major unmet needs within the indication. Overall, most of the neurologists agreed that the most significant unmet needs are for better physician and public awareness of the disease, especially as ocular MG can sometimes manifest as non-specific fatigue or can be nearly asymptomatic. While a diagnosis of MG is usually fast and reliable once a patient is referred to a neurologist, it can be easily misdiagnosed by primary care doctors due to the rarity of the disease. A misdiagnosis may mean a patient receives improper treatment as their disease worsens.
While the surveyed neurologists highly regarded the available techniques for diagnosing MG, they did highlight a major need for prognostic biomarkers that could help identify the treatment strategies that would be the most effective for patients with different MG types. MG is an extremely heterogeneous disease, which can make it challenging to select appropriate treatments for a patient. The neurologists agreed that the development of prognostic biomarkers could help predict the both likelihood of a patient experiencing long-lasting improvement of MG symptoms and their response to specific treatments.
One of the unmet needs that neurologists and key opinion leaders (KOLs) interviewed by GlobalData agreed on is the necessity for standardised treatment guidelines—more specifically, an update to the current Myasthenia Gravis Foundation of America (MGFA) guidelines. The biggest criticism of the MGFA guidelines among KOLs is the lack of class 0 classification for patients, which would account for the patients in remission who are symptom-free. Some KOLs also prefer to class their patients according to the antibody status, which is something the MGFA does not account for in its guidelines, so the neurologists tend to use other guidelines or their own personal experience when diagnosing and treating MG.
While the opinion of the surveyed high-prescribing neurologists was split regarding unmet needs surrounding the high cost of DMTs, KOLs consider the cost of available DMTs to be too high, making them unavailable for many MG patients who would otherwise likely benefit from their use. For example, in the US, most insurance companies will cover the cost of DMTs only if the patient has failed to respond to two to four previous off-label treatments, including acetylcholinesterase inhibitors, steroids, and immunosuppressants. Currently, the prices of DMTs that have been approved for MG vary greatly between the agents. The first-ever approved DMT for MG, Alexion’s Soliris (eculizumab), which launched in 2017, is priced at nearly $700,000 per year. Subsequent DMTs have been approved within the last two years, with Alexion’s Ultomiris (ravulizumab-cwvz) and Argenx’s Vyvgart (efgartigimod alfa-fcab) being priced at around $500,000 and $220,000 per year, respectively.
Although currently available DMTs have an almost immediate effect on treating MG symptoms and can slow progression, greatly improving patients’ daily lives, none of them are curative and need to be administered indefinitely, unless the patient enters remission. There are eight new pipeline drugs for MG in Phase III clinical trials, but most of them exhibit similar mechanisms of action as currently available DMTs, and none are likely to be curative. Furthermore, interviewed KOLs do not expect any of the upcoming pipeline agents to have a significant influence on the treatment pattern or availability of DMTs for non-refractory patients. Therefore, GlobalData expects most of the unmet needs in the MG to not be fully addressed over the next decade.