Clinical Pharmacy Services Manager Option Care Health, United States
Background: Efgartigimod alfa (Vyvgart®) is a novel therapy which, as of December 17, 2021, has received approval for patients with generalized myasthenia gravis (gMG) and a positive test for the acetylcholine receptor (AChR) antibody.1 Myasthenia gravis (MG) is a type of autoimmune disease with a hallmark symptom of muscle dysfunction. Signs of dysfunction typically originate in the extraocular muscles with affected persons experiencing diplopia/ptosis. When these symptoms begin to affect skeletal muscles outside of the extraocular muscles, the diagnosis becomes generalized myasthenia gravis (gMG). About 85% of patients with gMG have developed IgG autoantibodies, most commonly directed at the AChR. 3 The pathophysiology behind gMG revolves around the neuromuscular junction. AChR antibodies disrupt the receptors normal functioning and effect neuromuscular contractions. This can lead to severe degradation of muscle cells and chronic symptoms. Efgartigimod alfa, dosed 10 mg/kg once weekly for 4 weeks4, aims to lessen the effect of these autoantibodies. It is a fragment of an IgG antibody that attaches and blocks the neonatal Fc receptor (FcRn) prohibiting IgG antibodies from binding. IgG antibodies that cannot bind to FcRn are more easily eliminated from the body, therefore having a decreased effect on the AChR.
Per the International Consensus Guidance for Management of Myasthenia Gravis published in 2016, pyridostigmine, an acetylcholinesterase inhibitor, should be started first line for most patients with MG. If it is unsuccessful, immunosuppressive therapy is next in line with steroids being preferred over non-steroidal immunosuppressants.5. Non-steroidal therapies used for MG such as tacrolimus, methotrexate, rituximab, IVIg, and cyclophosphamide are next in line.4 Theses immunosuppressive therapy options come with significant risks and possible side effects. Efgartigimod-alfa, with its specific mechanism of action and strong data supporting its use, could become a cornerstone of MG treatment.
Purpose: This study aims to provide further information and data to continue the evaluation of this medication. This study will obtain data relating to how frequently the medication is used, if the medication has been effective and appropriate, and ensuring the medication is utilized optimally to benefit patients. The data will be combined and analyzed to gain a better understanding of the medications use in the patient population for the purpose of improving patient outcomes and quality of life.
Methods: This retrospective case study will include patients who have received efgartigimod alfa between January 2022 through September 2022. Each of those patients will be studied to assess dosing, prior therapies, concomitant therapies, successes, failures, and adverse events. Patient symptoms as reflected in the Myasthenia Gravis Activities of Daily Living (MG-ADL) and a fatigue scoring scale will be assessed.
Research involves the collection of existing data only. These sources are not publicly available and the information will be recorded by the investigator to ensure that the subjects cannot be identified. The project is IRB exempt.