ADAPT Forward is a platform study with the aim to look at how safe different drugs are and how well they work for people with myasthenia gravis. The goal is to find the best therapeutic approach to reduce patients' side effects and improve their quality of life.

This is a platform study and is governed by a single master protocol that enables multiple regimens to be evaluated in separate intervention-specific appendixes (ISAs).

The key design structure of the platform study comprises: common master protocol screening period, ISA-specific screening period, ISA treatment period of variable duration and design and ISA safety follow-up/follow-up period of variable duration.

Details on each study period will be specified in the ISAs. Following ISAs are included in this platform study:

• NCT07284420 - ADAPT Forward 1 - a study to evaluate empasiprubart IV as add-on therapy to efgartigimod IV in participants with AChR-Ab seropositive generalized myasthenia gravis with a partial clinical response to efgartigimod (https://www.clinicaltrials.gov/study/NCT07284420)

Inclusion Criteria:

• Is at least 18 years of age and the local legal age of consent for clinical studies
• Has been diagnosed with MG with consistent clinical features per the investigator's clinical judgment
• If receiving MG therapy, including nonsteroidal immunosuppressive drugs (NSIDs), corticosteroids, or acetylcholinesterase (AChE) inhibitors either in combination or alone, the participant should receive a stable dosage before master protocol screening

Exclusion Criteria:

• Known autoimmune disease or any medical condition other than the indication under study that would interfere with an accurate assessment of clinical symptoms of MG or puts the participant at undue risk
• Is MGFA (Myasthenia Gravis Foundation of America) Class V

Participants With AChR-Ab Seropositive Generalized Myasthenia Gravis With a Partial Clinical Response to Efgartigimod