Treatment of Myasthenia Gravis Exacerbation or Crisis With Efgartigimod: A Single Arm, Open Label Prospective Cohort Study
This study plans to learn more about if the drug efgartigimod can be used in the hospital to treat exacerbations in participants with myasthenia gravis (MG). Efgartigimod has been approved by the FDA for ongoing (chronic) treatment of generalized MG in adult patients who are anti-acetylcholine receptor (AChR) antibody positive but has not been studied in the treatment of worsening weakness requiring hospital admission (known as exacerbation). This investigation aims to see if using efgartigimod in this way improves symptoms and recovery from exacerbation, and how it affects certain MG markers in the blood. The main questions it aims to answer are: * Is efgartigimod effective as a hospital-administered acute therapy for participants with worsening MG (MG exacerbation) who require hospitalization? * Will efgartigimod lead to clinical improvement with a similar reduction in validated research scales, such as the Quantitative MG (QMG) scale, as standard of care therapies? Participants will receive 4 doses of efgartigimod over the course of 4 weeks with an additional follow-up visit at the clinic.
• Adults ≥ age 18 years with known generalized MG as identified by characteristic signs of generalized MG on clinical assessment and positive serology for AchR antibodies as well as one of the following:
‣ Documented positive response to cholinesterase inhibitors such as pyridostigmine or edrophonium
⁃ Abnormal decrement on slow repetitive nerve stimulation testing
⁃ Abnormal single fiber EMG
• Evidence of worsening weakness requiring hospital admission for stabilization and change in therapy as determined by a neuromuscular expert including:
‣ Quantitative Myasthenia Gravis (QMG) scale ≥ 11
⁃ MG-ADL score ≥ 6
⁃ Worsening weakness that is unlikely to be ameliorated by adjustment of current medications including impaired respiratory status, dysarthria, dysphagia, difficulty chewing, limb weakness, diplopia, ptosis.
• Ability to sign consent and be enrolled within 24 hours of hospital admission. For participants transferred to University of Colorado Hospital, the time of admission/presentation to the outside hospital is counted towards this 24-hour cap.