About the ExpanD Study

The ExpanD Study is researching an oral investigational medication for adults 18 years of age and older who have been diagnosed with generalized myasthenia gravis (gMG).

Who May Qualify

Eligible participants must:

  • Be at least 18 years of age
  • Have a confirmed diagnosis of gMG
  • Be on a stable dose of gMG medication
    (only applies to those currently on gMG treatment)

There are additional eligibility criteria, which the study team will discuss with you.

About the Investigational Medication

In this clinical research study, the oral investigational medication (ALXN2050) is being compared with placebo. A placebo is a drug that contains no active ingredients and allows researchers to more fully understand the effects of an investigational medication.

ALXN2050 or placebo will be administered orally twice a day. Participants will be chosen at random to receive either a high dose or a low dose of ALXN2050 or the placebo. After eight weeks, the placebo group will again be chosen at random to then receive either the high dose or the low dose of ALXN2050. Neither participants nor their study doctor will know which study treatment they have been assigned, but in case of an emergency, the study doctor can quickly find out.

Study Participation

The total duration of participation in the study will be approximately 125 weeks (a little over two years) and consists of:


This period may last up to four weeks. The study team will perform several assessments and procedures to determine whether patients are eligible to participate.

Primary Evaluation

This study treatment period lasts approximately eight weeks. After randomization, patients will receive their study treatment and attend visits at the study site for routine assessments and procedures.

Extended Treatment

This period lasts approximately 26 weeks. Participants initially receiving the placebo will again be chosen at random to receive either the high dose or the low dose of ALXN2050. Participants will continue to attend visits at the study site for routine assessments and procedures. Some visits can be performed through telemedicine.

Open-Label Extension

After completing the study treatment period, participants will enter an approximately one-and-a-half-year open-label extension period, in which all participants will continue to receive the investigational medication. Final study assessments will be performed 30 days after a participant’s final study treatment dose.

Please note: This website is for US residents only. If you live outside the US or want additional information on the ExpanD Study, please contact ClinicalTrials@Alexion.com or call: (+1) 855-752-2356.

Throughout your study participation, the study doctor may perform a number of tests and procedures, including but not limited to:

Medical history review

Physical exam

Vital sign measurements

Electrocardiogram (ECG)

Pregnancy test (if applicable)

Blood and urine sample collections

See if you may qualify