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

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 clinicalcriteria for Myasthenia Gravis Foundation of America Class II to IVa classification.

• In participants positive for Acetylcholine receptor antibody (anti-AChR) ormuscle-specific kinase antibody(anti-MuSK)

• In participants that are autoantibody seronegative and participants who arepositive 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 at least 50 percentage (%) of the total score due to non-ocular symptoms

• If treated with oral corticosteroids: should be on a stable daily dose for at least 4 weeks before randomization. In such case, the daily dose of oral steroids shouldnot exceed 20 milligrams(mg)/day for prednisone/ prednisolone or 16 mg/day formethylprednisolone

• If treated with acetylcholinesterase inhibitor should be on a stable daily dose forat least 4 weeks before randomization

• Have a body weight >= 40 kilograms

• Other protocol defined inclusion criteria could apply

Exclusion Criteria:

• 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 theparticipants regular treating physician recorded in the source documents, is notexclusionary

• Molecularly characterized or suspected congenital myasthenic syndrome, Lambert-Eatonmyasthenic syndrome, inherited myopathy, muscular dystrophy, acquired myopathy orany other neurologic or systematic disease that mimics MG muscular weakness

• Active, clinically significant viral, bacterial, or fungal infection, includingbrain MRI findings consistent with signs of infection such as PML, or any majorepisode of infection requiring hospitalization or treatment with parenteralanti-infectives within 4 weeks before or during Screening, or completion of oralantiinfectives within 2 weeks before or during Screening, or a history of recurrentinfections (i.e. 3 or more of the same type of infection in a 12-month rollingperiod). Vaginal candidiasis, onychomycosis, and genital or oral herpes simplexvirus considered by the Investigator to be sufficiently controlled would not beexclusionary.

• Has a history of or current diagnosis of active tuberculosis (TB)

• Active malignancy, or history of cancer

• Treatment with nonsteroidal immunosuppressants, used in gMG, such as azathioprine,mycophenolate mofetil, methotrexate, cyclosporine, tacrolimus within 4 weeks priorto randomization

• Treatment with eculizumab, rozanolixizumab efgartigimod, ravulizumab, or zilucoplanwithin 8 weeks prior to randomization

• History of thymectomy within 6 months prior to Screening.

• History of generalized seizures (except for history of infantile febrile seizures).

• Negative for Varicella Zoster Virus antibodies at screening.

• Other protocol defined exclusion criteria could apply