an open-label study to investigate the clinical efficacy of different dosing regimens of efgartigimod iv in patients with generalized myasthenia gravis

Conditions: Generalized Myasthenia Gravis

Summary: the purpose of this open-label study is to investigate the efficacy, safety, and tolerability of a continuous regimen of efgartigimod compared with a cyclic regimen in participants with generalized myasthenia gravis (gmg). study details include: the study duration will be up to 138 weeks (including screening and a safety follow-up of up to 9 weeks) * part a (regimen comparison period) - 21 weeks * part b (extension period) - up to 105 weeks the visit frequency, including virtual visits, will be weekly through week 21 and every 5 weeks for the remainder of the study.


Eligibility criteria:
inclusion criteria: * capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. * at least 18 years of age, at the time of signing the informed consent. * diagnosed with generalized myasthenia gravis (gmg) with confirmed documentation and supported by a physical exam and confirmed seropositivity for anti-acetylcholine receptor antibodies (achr-abs). * meets the clinical criteria as defined by the myasthenia gravis foundation of america (mgfa) class ii, iii, or iv * has an myasthenia gravis - activities of daily living (mg-adl) total score ≥5 at screening and the day 1 visit, with more than 50% of the score due to nonocular symptoms * concomitant gmg treatment is permitted. permitted concomitant gmg treatment includes nonsteroidal immunosuppressive drugs (nsids), steroids, and/or acetylcholinesterase (ache) inhibitors. if receiving corticosteroids and/or nsids, must be on a stable dose for at least 1 month before screening. * contraceptive use should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies and: women of childbearing potential must have a negative serum pregnancy test at screening and a negative urine pregnancy test at baseline before investigational medicinal product (imp) can be administered. exclusion criteria: * clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection at screening * a positive test for sars-cov-2 at screening * any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of the clinical symptoms of gmg and/or put the participant at undue risk * history of malignancy unless deemed cured by adequate treatment with no evidence of reoccurrence for ≥3 years before the first administration of the imp. participants with the following cancers can be included at any time, provided they are adequately treated at screening: basal cell or squamous cell skin cancer; carcinoma in situ of the cervix; carcinoma in situ of the breast; incidental histological finding of prostate cancer (tnm stage t1a or t1b) * clinical evidence of other significant serious diseases, a recent (\<3 months) major surgery, or any other condition that, in the opinion of the investigator, could confound the results of the study or put the participant at undue risk * a thymectomy within 3 months of screening * pregnant or lactating females and those who intend to become pregnant during the study or within 90 days of the last dose of imp * use of the following prior or concomitant therapies: 1. intravenous immunoglobulin (ivig) or subcutaneous immunoglobulin (scig) within 14 days of day 1 2. rituximab within 6 months of day 1 3. eculizumab within 1 month of day 1 4. other monoclonal antibodies (eg, adalimumab, tocilizumab, ixekizumab) within 5 half-lives of the monoclonal antibodies before day 1 5. use of any other investigational product within 3 months or 5 half-lives, whichever is longer, before day 1 6. receipt of a live or live-attenuated vaccines received within 4 weeks of screening. the receipt of any inactivated, subunit, polysaccharide, conjugate vaccine at any time before screening is not considered exclusionary. * previous participation in a clinical study or patient access program during which they were treated with efgartigimod * positive serum test at screening for an active viral infection with any of the following conditions: hepatitis b virus (hbv) that is indictive of an acute or chronic infection; hepatitis c virus (hcv) based on hcv antibody assay (unless associated with a negative hcv rna test); hiv based on test results that are associated with an aids-defining condition or a cd4 count \<200 cells/mm3 * total igg \<6 g/l at screening * known hypersensitivity reaction to efgartigimod or any of its excipients * the participant stands in any relationship of dependency with the sponsor. * the participant has been institutionalized due to an official or judicial order.