Efficacy and Safety of a New Formulation of Oral Cladribine Compared With Placebo in Participants With Generalized Myasthenia Gravis (MyClad)

Recruiting now · Phase 3 · Has a placebo group

Conditions studied: Generalized Myasthenia Gravis

In brief

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. This study is divided into 3 periods: the double-blind placebo control (DBPC) pivotal period, and 2 extensions, the blinded extension (BE) and the retreatment (RT) period. Furthermore, in trial interviews will be conducted as a sub-study to MyClad with a sub-set of participants to gain an in depth understanding of the participant cladribine treatment and study experience.

Key facts

Study ID

NCT06463587

Run by

Merck Healthcare KGaA, Darmstadt, Germany, an affiliate of Merck KGaA, Darmstadt, Germany

People needed

264

Starts

2024-06-25

Expected to finish

2030-11-12

Last updated by the study team

2026-07-23

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• 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 i.e. not positive for anti-AChR and anti-MuSK antibodies 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 least 3 months prior to and during screening. In such case, the daily dose of oral steroids should not exceed 20 milligrams(mg)/day for prednisone/ prednisolone, 16 mg/day for methylprednisolone, 3 mg/day for dexamethasone, or 80 mg for hydrocortisone or equivalent doses for other corticosteroids.
• If treated with acetylcholinesterase inhibitor should be on a stable daily dose (pyridostigmine dose ≤ 480 mg/day or neostigmine ≤ 300 mg/day) for at least 3 months prior to and during screening
• Have a body weight >= 40 kilograms
• Other protocol defined inclusion criteria could apply

You may not qualify if…

• Immunologic disorder other than MG or any other condition requiring chronic oral, intravenous, intramuscular, or intraarticular corticosteroid therapy. Well-controlled thyroid disease, as per the Treating Investigator or the participants regular treating physician recorded in the source documents, is not exclusionary
• Molecularly characterized or suspected congenital myasthenic syndrome, Lambert-Eaton myasthenic syndrome, inherited myopathy, muscular dystrophy, acquired myopathy or any other neurologic or systematic disease that mimics MG muscular weakness
• Active, clinically significant viral, bacterial, or fungal infection, including brain MRI or chest X-ray findings consistent with signs of infection such as PML or TB, or any major episode of infection requiring hospitalization or treatment with parenteral anti-infectives within 8 weeks prior or during Screening, or completion of oral anti-infectives within 8 weeks prior or during Screening. Vaginal candidiasis, onychomycosis, and genital or oral herpes simplex virus considered by the Investigator to be sufficiently controlled would not be exclusionary
• Has a history of or current diagnosis of active tuberculosis (TB) or is currently undergoing treatment for latent TB infection or has an untreated latent TB infection as determined by documented results within 3 months of the Screening Visit of a positive TB skin test .
• Active malignancy, or history of cancer or signs of malignancy in any Screening assessment
• Treatment with nonsteroidal immunosuppressants, used in gMG, such as azathioprine, mycophenolate mofetil, methotrexate, cyclosporine, cyclophosphamide, tacrolimus within 4 weeks prior to randomization
• Treatment with FcRn or complement inhibitors (such as eculizumab, rozanolixizumab efgartigimod, ravulizumab, zilucoplan or nipocalimab) within 8 weeks prior to randomization
• History of thymectomy within 6 months prior to Screening.
• History of generalized seizures (except for history of febrile seizures during the participant's childhood).
• Negative or indeterminate for Varicella Zoster Virus antibodies at screening
• History of myasthenic crisis in the last 12 months prior to and during screening
• History of recurrent infections (that is 3 or more infections per year documented in available source data) within the last 2 years
• Discontinuation of treatment with any non-steroidal immunosuppressants used in gMG, such as azathioprine, mycophenolate mofetil, methotrexate, cyclosporine, cyclophosphamide, tacrolimus within the last 6 months prior to Screening
• If treated with non-steroidal immunosuppressants for gMG, the dose at Screening higher than 50 mg/day for azathioprine, 500 mg/day for mycophenolate mofetil, 1 mg/day for tacrolimus, 50 mg/day for cyclosporine, 25 mg/day for cyclophosphamide, or 7.5 mg/week for methotrexate
• Participation in clinical study of any investigational drug within 6 months, or 5 half-lives of the investigational drug used in the previous clinical study prior to randomization, whichever is longer. However, participants with any prior exposure to cladribine may not enter the study regardless of timing of exposure
• Other protocol defined exclusion criteria could apply

Where it is running

• Fundacion Rosarina de Neurorehabilitacion — Rosario, Argentina (enrolling)
• University of Connecticut Health Center - Department of Medicine — Farmington, Connecticut, United States (enrolling)
• The George Washington University Medical Faculty Associates Foggy Bottom South Pavilion — Washington D.C., District of Columbia, United States (enrolling)
• Arizona Neuroscience Research, LLC — Phoenix, Arizona, United States (enrolling)
• SFM Clinical Research, LLC — Boca Raton, Florida, United States (enrolling)
• University of Florida Health Science Center - 300120311 — Jacksonville, Florida, United States (enrolling)
• Neurology Associates, P. A. — Maitland, Florida, United States (enrolling)
• University of South Florida - PARENT - PARENT — Tampa, Florida, United States (enrolling)
• Neurology of Central Florida Research Center, LLC — Altamonte Springs, Florida, United States (enrolling)
• UNC Hospitals - PARENT — Chapel Hill, North Carolina, United States (enrolling)
• Atrium Health Wake Forest Baptist — Winston-Salem, North Carolina, United States (enrolling)
• Miami Valley Hospital South — Centerville, Ohio, United States (enrolling)
• University of Cincinnati — Cincinnati, Ohio, United States (enrolling)
• Clinical Trials of South Carolina - Charleston — Charleston, South Carolina, United States (enrolling)
• Erlanger Health, Inc. - 1123255 — Chattanooga, Tennessee, United States (enrolling)
• Baylor Scott & White Research Institute - Baylor Scott & White Research Institute — Dallas, Texas, United States (enrolling)
• ANESC Research — El Paso, Texas, United States (enrolling)
• Baylor Scott & White Neurology - McKinney — McKinney, Texas, United States (enrolling)
• The University of Vermont Medical Center — Burlington, Vermont, United States (enrolling)
• University of Kansas Medical Center Research Institute, Inc. - 3901 Rainbow (MAIN) — Kansas City, Kansas, United States (enrolling)
• Expertia S.A- Mautalen Salud e Investigación — Ciudad Autonoma Buenos Aires, Argentina (enrolling)
• Instituto de Investigaciones Neurologicas Raul Carrea, FLENI - de Investigaciones Clinicas del área de Cardiología y enfermedades metabólicas asociadas — Ciudad Autonoma Buenos Aires, Argentina (enrolling)
• Instituto de Investigaciones Metabolicas (IDIM) — Ciudad Autonoma Buenos Aires, Argentina (enrolling)
• Hospital Cordoba — Córdoba, Argentina (enrolling)
• INECO Neurociencias Oroño — Rosario, Argentina (enrolling)

Full record on ClinicalTrials.gov

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