NCT06463587 · Merck Healthcare KGaA, Darmstadt, Germany, an affiliate of Merck KGaA, Darmstadt, Germany
Efficacy and Safety of a New Formulation of Oral Cladribine Compared With Placebo in Participants With Generalized Myasthenia Gravis (MyClad)
What this study is about
The purpose of this clinical study is to determine the effectiveness and safety of a new taken by mouth cladribine formulation in participants with Generalized Myasthenia Gravis (gMG) in comparison to placebo. It will also investigate the sustained effectiveness, the need for retreatment, and the long-term safety of taken by mouth cladribine in gMG.
View original scientific description
The purpose of this clinical study is to determine the efficacy and safety of a new oral cladribine formulation in participants with Generalized Myasthenia Gravis (gMG) in comparison to placebo. It will also investigate the sustained efficacy, the need for retreatment, and the long-term safety of oral cladribine in gMG. An additional component is included to characterize the Pharmacokinetics (PK) of the new cladribine formulation in gMG participants.
Interventions
OTHER
Placebo
Participants will receive placebo matched to cladribine in two courses separated by 4 weeks.
DRUG
Cladribine Low Dose
Participants will receive cladribine low dose in two courses separated by 4 weeks.
DRUG
Cladribine High Dose
Participants will receive cladribine high dose in two courses separated by 4 weeks.
Primary outcome measures
Change from Baseline in Myasthenia Gravis - Activities of Daily Living (MG-ADL) Scale Score at Week 24 During the Double-Blind Placebo Controlled (DBPC) Period
Time frame: Baseline, Week 24
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Adults of ≥ 18 years of age at the time of signing the informed consent.
- Diagnosis of Myasthenia Gravis with generalized muscle weakness, meeting clinical criteria for Myasthenia Gravis Foundation of America Class II to IVa classification.
- In participants positive for Acetylcholine receptor antibody (anti-AChR) or muscle-specific kinase antibody(anti-MuSK)
- In participants that are autoantibody seronegative and participants who are positive for anti-low-density lipoprotein receptor-related protein 4 antibodies (anti-LRP4)
- Has a Screening and Baseline MG-ADL score more than or equal to (\>=) 6 with \>= 50 percentage (%) of the total score due to non-ocular symptoms. Screening and Baseline MG-ADL scores must be stable. The difference between the Screening and Baseline scores should not be more than 2 and there should be no reported MG exacerbation during the Screening period
- If treated with oral corticosteroids: should be on a stable daily dose for at
Where
- Phoenix, Arizona
- Longmont, Colorado
- Farmington, Connecticut
- Washington D.C., District of Columbia
- Altamonte Springs, Florida
- Boca Raton, Florida
- Jacksonville, Florida
- Maitland, Florida
- Tampa, Florida
- Kansas City, Kansas
- Chapel Hill, North Carolina
- Winston-Salem, North Carolina
And 9 more locations — see the full list below.
Collaborators
EMD Serono Research & Development Institute, Inc.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 29, 2026 · Source of record for eligibility and locations