While myasthenia gravis (MG), an autoimmune neuromuscular disorder, can be treated, there is a smaller subset of patients who are treatment-refractory. Those whose condition is not easily treated are thought to have generalized myasthenia gravis (gMG). However, in a recent press release, pharmaceutical company Alexion Pharmaceuticals (“Alexion”) shared positive topline data from a Phase 3 clinical trial evaluating Ultomiris (ravulizumab-cwvz) for patients with gMG.
According to Alexion, Ultomiris is:
the first and only long-acting C5 inhibitor administered every 8 weeks in adults. In maintenance dosing, ULTOMIRIS works by inhibiting the C5 protein in the terminal complement cascade, a part of the body’s immune system.
Previously, Ultomiris was approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS).
Within this particular trial, researchers evaluated Ultomiris for patients with gMG. In terms of the trial’s primary endpoint, researchers looked at a change in the MG-ADL score after a 26-week period. Findings included:
- Patients taking Ultomiris reported a higher quality of life (QOL) and reduced symptoms, with a sustained treatment duration lasting for up to 52 weeks (via an extension study).
- There was a significant improvement in MG-ADL for patients taking Ultomiris as compared to a placebo.
- Due to the positive results, Alexion looks to file an indication for Ultomiris and gMG by the start of 2022.
Generalized Myasthenia Gravis (gMG)
As explained above, MG is an autoimmune neuromuscular disorder. In fact, the name myasthenia gravis literally translates to “grave muscle weakness.” But while MG can be treated, a number of patients do not respond to treatment; experience frequent relapses; develop extreme or life-threatening side effects following immunosuppressants; and are not stable even while taking a treatment regimen. An estimated 20% of patients with gMG will experience myasthenic crisis, in which muscle weakness is so present that patients often require respiratory support for ventilation.
gMG occurs when the immune system creates antibodies which mistakenly attack the neuromuscular junction. Normally, at the neuromuscular junction, nerves and muscles work together to cause muscle contractions. When the antibodies attack the neuromuscular junction, it inhibits communication between nerves and muscles, causing weakness. Symptoms of gMG include:
- Debilitating muscle weakness
- Extreme fatigue
- Shortness of breath and/or difficulty breathing
- Difficulty chewing, swallowing, speaking, walking, or performing daily tasks
- Slurred speech
- Eyelid drooping on one or both side
- Changes in vision (diplopia; blurriness)
- Respiratory failure