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

May 19, 2026 updated by: Merck Healthcare KGaA, Darmstadt, Germany, an affiliate of Merck KGaA, Darmstadt, Germany

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 3-Arm, 3-Period Study to Assess the Efficacy and Safety of a New Formulation of Oral Cladribine Compared With Placebo in Participants With Generalized Myasthenia Gravis (MyClad)

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.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

264

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Argentina
      • Ciudad Autonoma Buenos Aires, Argentina, 1427
        • Recruiting
        • Expertia S.A- Mautalen Salud e Investigación
        • Principal Investigator:
          • Valeria Salutto
        • Contact:
      • Ciudad Autonoma Buenos Aires, Argentina, C1012AAR
        • Recruiting
        • Instituto de Investigaciones Metabolicas (IDIM)
        • Principal Investigator:
          • Fatima Pagani Cassara
        • Contact:
      • Ciudad Autonoma Buenos Aires, Argentina, 1428
        • Recruiting
        • Instituto de Investigaciones Neurologicas Raul Carrea, FLENI - de Investigaciones Clinicas del área de Cardiología y enfermedades metabólicas asociadas
        • Contact:
        • Principal Investigator:
          • Alberto Daniel Rivero
      • Córdoba, Argentina
        • Recruiting
        • Hospital Cordoba
        • Principal Investigator:
          • Susana del Liwacki
        • Contact:
      • Rosario, Argentina
      • Rosario, Argentina
      • San Juan, Argentina, 5400
        • Recruiting
        • CER San Juan Centro Polivalente de Asistencia e Inv. Clinica
        • Contact:
        • Principal Investigator:
          • Juan Carlos Giugni
      • San Miguel de Tucumán, Argentina
  • Australia
      • Southport, Australia
    • New South Wales
      • Camperdown, New South Wales, Australia, 2050
    • Queensland
      • Birtinya, Queensland, Australia, 4575
    • South Australia
      • City of Burnside, South Australia, Australia, SA 5072
        • Recruiting
        • John Hunter Hospital - PARENT
        • Contact:
        • Principal Investigator:
          • Myintzu Min
    • Victoria
  • Belgium
  • Bulgaria
      • Montana, Bulgaria, 3400
        • Recruiting
        • Medical Center Hera - branch Montana
        • Contact:
        • Principal Investigator:
          • Plamen Pelov
      • Pleven, Bulgaria, 5800
        • Recruiting
        • UMHAT 'Dr. Georgi Stranski', EAD
        • Principal Investigator:
          • Maya Danovska-Mladenova
        • Contact:
      • Plovdiv, Bulgaria, 4000
      • Sofia, Bulgaria, 1606
      • Sofia, Bulgaria, 1113
        • Recruiting
        • MHATNP "Sv.Naum", EAD - Third Neurology Clinic
        • Contact:
        • Principal Investigator:
          • Ivan G Milanov
  • China
    • Anhui
      • Anhui Sheng, Anhui, China, 233000
        • Recruiting
        • The First Affiliated Hospital Of Bengbu Medical College
        • Contact:
        • Principal Investigator:
          • Weidong Qian
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100730
        • Recruiting
        • Peking Union Medical College Hospital
        • Principal Investigator:
          • Yuzhou Guan
        • Contact:
      • Beijing, Beijing Municipality, China, 100053
        • Recruiting
        • Xuanwu Hospital Capital Medical University
        • Principal Investigator:
          • Yuwei Da
        • Contact:
    • Guangdong
      • Guangzhou, Guangdong, China, 510405
        • Recruiting
        • The First Affiliated Hospital of Guangzhou University of Chinese Medicine - 300164595
        • Contact:
        • Principal Investigator:
          • Qilong Jiang
    • Guizhou
      • Zunyi, Guizhou, China, 563099
        • Recruiting
        • Affiliated Hospital of Zunyi Medical University
        • Contact:
        • Principal Investigator:
          • Zucai Xu
    • Hebei
      • Shijiazhuang, Hebei, China, 050000
        • Recruiting
        • Shijiazhuang People's Hospital
        • Contact:
        • Principal Investigator:
          • Guoyan Qi
    • Henan
      • Zhengzhou, Henan, China, 450003
        • Recruiting
        • Henan Provincial People's Hospital
        • Contact:
        • Principal Investigator:
          • Mingming Ma
    • Hu'nan
      • Changsha, Hu'nan, China, 410008
        • Recruiting
        • Xiangya Hospital, Central South University
        • Principal Investigator:
          • Huan Yang
        • Contact:
    • Hubei
      • Wuhan, Hubei, China, 430030
        • Recruiting
        • Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology
        • Principal Investigator:
          • Zhijun Li
        • Contact:
    • Jilin
      • Changchun, Jilin, China, 130021
        • Recruiting
        • The First Hospital of Jilin University - The First Hospital of Jilin University
        • Principal Investigator:
          • Hui Deng
        • Contact:
      • Changchun, Jilin, China, 130033
        • Recruiting
        • China-Japan Union Hospital of Jilin University - 300173736
        • Contact:
        • Principal Investigator:
          • Songyan Liu
    • Liaoning
      • Shenyang, Liaoning, China, 110004
        • Recruiting
        • Shengjing Hospital of China Medical University
        • Contact:
        • Principal Investigator:
          • Juan Feng
    • Shanghai Municipality
      • Shanghai, Shanghai Municipality, China, 200040
        • Recruiting
        • Huashan Hospital, Fudan University - Neurology
        • Contact:
        • Principal Investigator:
          • Sushan Luo
    • Shanxi
      • Xi’an, Shanxi, China, 710038
        • Recruiting
        • Xi 'an International Medical Center
        • Contact:
        • Principal Investigator:
          • Hong Lin
    • Sichuan
      • Chengdu, Sichuan, China, 610041
        • Recruiting
        • West China Hospital, Sichuan University
        • Principal Investigator:
          • Hongyu Zhou
        • Contact:
  • France
      • Paris, France, 75013
        • Recruiting
        • Groupe Hospitalier Pitie-Salpetriere - Centre Référent Maladies Rares SLA - Neurologie
        • Contact:
        • Principal Investigator:
          • Anthony Behin
    • Alpes Maritimes
      • Nice, Alpes Maritimes, France, 06002
        • Recruiting
        • CHU Nice - Hôpital Pasteur - Cardiology
        • Principal Investigator:
          • Saskia Bresch
        • Contact:
    • Bas Rhin
      • Strasbourg, Bas Rhin, France, 67098
    • Isere
      • La Tronche, Isere, France, 38700
        • Recruiting
        • CHU de Grenoble - Hôpital Albert Michallon - Centre de Références des Maladies Neuromusculaires
        • Contact:
        • Principal Investigator:
          • Emmeline Lagrange
    • Paris
      • Paris, Paris, France, 75940
        • Recruiting
        • Fondation Ophtalmologique Adolphe de Rothschild - Service de neurologie
        • Principal Investigator:
          • Antoine Gueguen
        • Contact:
    • Puy De Dome
      • Clermont-Ferrand, Puy De Dome, France, 63003
        • Recruiting
        • CHU Clermont Ferrand - Hopital Gabriel Montpied - service de neurologie B
        • Contact:
        • Principal Investigator:
          • Frederic Taithe
    • Rhone
      • Bron, Rhone, France, 69677
        • Recruiting
        • Hopital Neurologique Pierre Wertheimer - Pathologies neuro-musculaires. Electromyographie
        • Contact:
        • Principal Investigator:
          • Francoise Bouhour
    • Val De Marne
      • Créteil, Val De Marne, France, 94010
        • Recruiting
        • Hôpital Henri Mondor - Service de Neurologie
        • Principal Investigator:
          • Edoardo Malfatti
        • Contact:
  • Georgia
      • Tbilisi, Georgia, 0160
      • Tbilisi, Georgia, 0114
      • Tbilisi, Georgia, 0114
  • Germany
      • Berlin, Germany, 10117
        • Recruiting
        • Charité Universitaetsmedizin Berlin - Campus Charité Mitte - Klinik fuer Neurologie
        • Contact:
        • Sub-Investigator:
          • Sarah Hoffmann
    • Lower Saxony
      • Göttingen, Lower Saxony, Germany, 37075
        • Recruiting
        • Universitaetsmedizin Goettingen - Abteilung fuer Nephrologie und Rheumatologie
        • Contact:
        • Principal Investigator:
          • Jana Zschuentzsch
      • Hanover, Lower Saxony, Germany, 30625
        • Recruiting
        • Medizinische Hochschule Hannover - Klinik fur Neurologie mit Klinischer Neurophysiol
        • Principal Investigator:
          • Thomas Skripuletz
        • Contact:
    • North Rhine-Westphalia
      • Bochum, North Rhine-Westphalia, Germany, 44791
      • Düsseldorf, North Rhine-Westphalia, Germany, 40225
        • Recruiting
        • Universitaetsklinikum Duesseldorf AoeR - Klinik fuer Neurologie
        • Contact:
        • Principal Investigator:
          • Michael Gliem
    • Saxony
      • Dresden, Saxony, Germany, 01307
        • Recruiting
        • Universitaetsklinikum Carl Gustav Carus TU Dresden - Medizinische Klinik I
        • Contact:
        • Principal Investigator:
          • Jochen Schaefer
      • Leipzig, Saxony, Germany, 04103
    • Schleswig-Holstein
      • Lübeck, Schleswig-Holstein, Germany, 23562
        • Recruiting
        • Universitaetsklinikum Schleswig-Holstein - Campus Luebeck - Neurologie
        • Principal Investigator:
          • Julian Grosskreutz
        • Contact:
  • Greece
      • Larissa, Greece, 41500
        • Recruiting
        • University General Hospital of Larissa - Rheumatology Clinic
        • Principal Investigator:
          • Efthymios Dardiotis
        • Contact:
      • Pátrai, Greece, 26504
        • Recruiting
        • University Hospital of Patra
        • Principal Investigator:
          • Elisabeth Chroni
        • Contact:
      • Thessaloniki, Greece, 54636
        • Recruiting
        • AHEPA General Hospital of Thessaloniki
        • Contact:
        • Principal Investigator:
          • Vasilios Kimiskidis
  • Hungary
      • Szeged, Hungary, 6725
        • Recruiting
        • Szegedi Tudomanyegyetem Szent-Gyorgyi Albert Klinikai Kozpont - Neurologiai Klinika
        • Contact:
        • Principal Investigator:
          • Peter Klivenyi
  • India
    • Andhra Pradesh
      • Hyderabad, Andhra Pradesh, India, 500082
        • Recruiting
        • Nizam's Institute of Medical Sciences
        • Contact:
        • Principal Investigator:
          • Sireesha Yareeda
      • Hyderabad, Andhra Pradesh, India, 500082
        • Recruiting
        • Yashoda Super Speciality Hospital - 300158817
        • Contact:
        • Principal Investigator:
          • Jaydip Ray Chaudhari
    • Karnataka
      • Bangalore, Karnataka, India, 560034
        • Recruiting
        • St John's Medical College Hospital
        • Contact:
        • Principal Investigator:
          • Gosala R Sarma
      • Bangalore, Karnataka, India, 560002
        • Recruiting
        • Bangalore Medical College and Victoria Hospital - 300148268
        • Contact:
        • Principal Investigator:
          • Praveen Kumar
      • Mangalore, Karnataka, India, 575001
        • Recruiting
        • Mallikatta Neurocentre
        • Principal Investigator:
          • Shankara Nellikunja
        • Contact:
    • Maharashtra
      • Nashik, Maharashtra, India, 422005
        • Recruiting
        • Chopda Medicare & Research Centre - 300188248
        • Contact:
        • Principal Investigator:
          • Amit Yeole
      • Pune, Maharashtra, India, 411030
        • Recruiting
        • Deenanath Mangeshkar Hospital and Research Centre - Department of Neurology
        • Principal Investigator:
          • Rahul Kulkarni
        • Contact:
  • Italy
      • Bergamo, Italy, 24127
        • Recruiting
        • Azienda Socio Sanitaria Territoriale Papa Giovanni
        • Principal Investigator:
          • Manlio Sgarzi
        • Contact:
      • Bologna, Italy, 40139
        • Recruiting
        • IRCCS Istituto delle Scienze Neurologiche di Bologna - Unità Operativa Complessa Clinica Neurologica
        • Contact:
        • Principal Investigator:
          • Maria Pia Giannoccaro
      • Genova, Italy, 16132
        • Recruiting
        • IRCCS Ospedale Policlinico San Martino - Neuroradiologia
        • Contact:
        • Principal Investigator:
          • Martina Garnero
      • Milan, Italy, 20133
      • Pavia, Italy, 27100
        • Recruiting
        • Fondazione Istituto Neurologico Casimiro Mondino - Neurology
        • Contact:
        • Principal Investigator:
          • Matteo Gastaldi
      • Roma, Italy, 00133
        • Recruiting
        • Azienda Ospedaliera Universitaria Policlinico Tor Vergata - U.O.C. Neurologia
        • Contact:
        • Principal Investigator:
          • Roberto Carlo Emilio Massa
      • Treviso, Italy, 31100
    • Roma
      • Rome, Roma, Italy, 00168
  • Japan
    • Chiba
      • Chiba, Chiba, Japan, 260-8677
        • Recruiting
        • Chiba University Hospital - Dept of Neurology
        • Contact:
        • Principal Investigator:
          • Akiyuki Uzawa
      • Narita-shi, Chiba, Japan, 286-8520
        • Recruiting
        • IUHW Narita Hospital - Dept of Neurology
        • Principal Investigator:
          • Hiroyuki Murai
        • Contact:
    • Fukuoka
      • Fukuoka, Fukuoka, Japan, 814-0180
        • Recruiting
        • Fukuoka University Hospital - Dept of Neurology/Health Care
        • Contact:
        • Principal Investigator:
          • Yasuhiko Baba
    • Fukushima
      • Koriyama-shi, Fukushima, Japan, 963-8563
    • Hokkaido
      • Hakodate-shi, Hokkaido, Japan, 392006
    • Iwate
      • Hanamaki-shi, Iwate, Japan, 025-0082
        • Recruiting
        • General Hanamaki Hospital - Dept of Neurology
        • Principal Investigator:
          • Kimiaki Utsugisawa
        • Contact:
    • Kagawa-ken
      • Kita-gun, Kagawa-ken, Japan, 7610793
    • Nagasaki
      • Nagasaki, Nagasaki, Japan, 852-8501
        • Recruiting
        • Nagasaki University Hospital - Dept of Neurology
        • Contact:
        • Principal Investigator:
          • Shunsuke Yoshimura
    • Saitama
      • Iruma-gun, Saitama, Japan, 350-0495
        • Recruiting
        • Saitama Medical University Hospital - Dept of Neurology/Stroke Care Unit
        • Contact:
        • Principal Investigator:
          • Genko Omaya
    • Tokyo-To
      • Meguro-ku, Tokyo-To, Japan, 153-8515
        • Recruiting
        • Toho University Ohashi Medical Center - Dept of Neurology
        • Contact:
        • Principal Investigator:
          • Shingo Konno
      • Shinjuku-ku, Tokyo-To, Japan, 160-0023
        • Recruiting
        • Tokyo Medical University Hospital - Dept of Neurology
        • Principal Investigator:
          • Masayuki Masuda
        • Contact:
  • Poland
      • Gdansk, Poland, 80-214
        • Recruiting
        • Uniwersyteckie Centrum Kliniczne - Dept of Neurology
        • Contact:
        • Principal Investigator:
          • Malgorzata M Bilinska
      • Krakow, Poland, 31-505
        • Recruiting
        • Krakowska Akademia Neurologii Sp z o.o. Centrum Neurologii Klinicznej
        • Contact:
        • Principal Investigator:
          • Andrzej Szczudlik
      • Krakow, Poland, 30-688
        • Recruiting
        • SP ZOZ Szpital Uniwersytecki w Krakowie - Zespó
        • Principal Investigator:
          • Agnieszka Slowik
        • Contact:
      • Warsaw, Poland, 02-091
      • Zabrze, Poland
        • Recruiting
        • Wielospecjalistyczne Centrum Medyczne Ibismed - Dept of Neurology
        • Principal Investigator:
          • Monika Adamczyk Sowa
        • Contact:
  • Romania
      • Bucharest, Romania, 040215
      • Bucharest, Romania, 022328
        • Recruiting
        • Institutul Clinic Fundeni - parent
        • Contact:
        • Principal Investigator:
          • Crisanda Vilciu
      • Constanța, Romania, 900591
        • Recruiting
        • Brainaxy Clinic S.R.L.
        • Contact:
        • Principal Investigator:
          • Any Axelerad
      • Târgu Mureş, Romania, 540136
        • Recruiting
        • Spitalul Clinic Judetean de Urgenta Targu Mures - Sectia Clinica Neurologie I
        • Contact:
        • Principal Investigator:
          • Targu Mures
  • South Korea
      • Daegu, South Korea, 41404
        • Recruiting
        • Kyungpook National University Chilgok Hospital
        • Principal Investigator:
          • Jin-Sung Park
        • Contact:
      • Gwangju, South Korea, 61469
        • Recruiting
        • Chonnam National University Hospital
        • Contact:
        • Principal Investigator:
          • Tai Seung Nam
      • Seoul, South Korea, 06351
        • Recruiting
        • Samsung Medical Center
        • Principal Investigator:
          • Byoung Joon Kim
        • Contact:
      • Seoul, South Korea, 138-736
        • Recruiting
        • Asan Medical Center
        • Principal Investigator:
          • Young-Min Lim
        • Contact:
      • Seoul, South Korea, 136-705
        • Recruiting
        • Korea University Anam Hospital
        • Principal Investigator:
          • Byung-Jo Kim
        • Contact:
      • Seoul, South Korea, 156707
        • Recruiting
        • Seoul Metropolitan Government Seoul National University Boramae Medical Center
        • Principal Investigator:
          • Yoon-Ho Hong
        • Contact:
      • Seoul, South Korea
        • Withdrawn
        • Keimyung University Dongsan Hospital
  • Spain
      • Barcelona, Spain, 08035
        • Recruiting
        • Hospital Universitari Vall d'Hebron - Neurology Dept
        • Principal Investigator:
          • Raul Juntas-Morales
        • Contact:
      • Valencia, Spain, 46026
        • Recruiting
        • Hospital Universitari i Politecnic La Fe - Pediatry Department
        • Principal Investigator:
          • Teresa Sevilla Mantecon
        • Contact:
    • Barcelona
      • Badalona, Barcelona, Spain, 08916
        • Recruiting
        • Hospital Universitari Germans Trias i Pujol - Servicio de Neurologia
        • Contact:
        • Principal Investigator:
          • Sebastian Figueroa Bonaparte
    • Córdoba
      • Córdoba, Córdoba, Spain, 14004
        • Recruiting
        • Hospital Universitario Reina Sofia - Neurology Dept
        • Principal Investigator:
          • Eduardo Aguera Morales
        • Contact:
    • Principality of Asturias
      • Oviedo, Principality of Asturias, Spain, 33011
        • Recruiting
        • Hospital Universitario Central de Asturias - Servicio de Neurologia
        • Contact:
        • Principal Investigator:
          • German Moris de la Tassa
  • Sweden
      • Göteborg, Sweden, 41345
      • Karlstad, Sweden, 65230
      • Stockholm, Sweden, 18288
  • Switzerland
      • Bern, Switzerland, 3010
        • Recruiting
        • Inselspital - Universitaetsspital Bern - Neuropsychologische Rehabilitation, Neurologie
        • Principal Investigator:
          • Robert Hoepner
        • Contact:
  • Taiwan
      • Kaohsiung City, Taiwan, 83301
        • Recruiting
        • Kaohsiung Chang Gung Memorial Hospital
        • Principal Investigator:
          • Nai-Wen Tsai
        • Contact:
      • Taichung, Taiwan, 404327
      • Taipei, Taiwan, 11217
        • Recruiting
        • Taipei Veterans General Hospital
        • Principal Investigator:
          • Yi-Chung Lee
        • Contact:
      • Taipei, Taiwan, 111
        • Recruiting
        • Shin Kong Wu Ho-Su Memorial Hospital
        • Principal Investigator:
          • Jiann Horng Yeh
        • Contact:
  • Turkey (Türkiye)
      • Trabzon, Turkey (Türkiye), 61080
        • Recruiting
        • Karadeniz Tecnical Uni. Med. Fac. - Neurology Departmen
        • Contact:
        • Principal Investigator:
          • Cavit Boz
  • United Kingdom
    • Nottinghamshire
      • Nottingham, Nottinghamshire, United Kingdom, NG7 2UH
        • Recruiting
        • Nottingham University Hospitals NHS Trust
        • Contact:
        • Principal Investigator:
          • Philip Ambrose
    • South Yorkshire
      • Sheffield, South Yorkshire, United Kingdom, S10 2JF
        • Recruiting
        • Royal Hallamshire Hospital - Dept of Neurology
        • Contact:
        • Principal Investigator:
          • Channa Hewamadduma
  • United States
    • Arizona
    • Colorado
      • Longmont, Colorado, United States, 80501
    • Connecticut
      • Farmington, Connecticut, United States, 06030-5550
        • Recruiting
        • University of Connecticut Health Center - Department of Medicine
        • Contact:
        • Principal Investigator:
          • Amanda Hernandez
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20037
        • Recruiting
        • The George Washington University Medical Faculty Associates Foggy Bottom South Pavilion
        • Contact:
        • Principal Investigator:
          • Henry J Kaminski
    • Florida
      • Altamonte Springs, Florida, United States, 32714
        • Recruiting
        • Neurology of Central Florida Research Center, LLC
        • Principal Investigator:
          • Alicia V Cabrera
        • Contact:
      • Boca Raton, Florida, United States, 33487
      • Jacksonville, Florida, United States, 32209
        • Recruiting
        • University of Florida Health Science Center - 300120311
        • Contact:
        • Principal Investigator:
          • Michael T Pulley
      • Maitland, Florida, United States, 32751
        • Recruiting
        • Neurology Associates, P. A.
        • Contact:
        • Principal Investigator:
          • Adam D Slansky
      • Tampa, Florida, United States, 33612
        • Recruiting
        • University of South Florida - PARENT - PARENT
        • Principal Investigator:
          • Tuan H Vu
        • Contact:
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • Recruiting
        • University of Kansas Medical Center Research Institute, Inc. - 3901 Rainbow (MAIN)
        • Principal Investigator:
          • Mamatha Pasnoor
        • Contact:
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
      • Winston-Salem, North Carolina, United States, 27157-1078
        • Recruiting
        • Atrium Health Wake Forest Baptist
        • Contact:
        • Principal Investigator:
          • Rachana B Gandhi Mehta
    • Ohio
      • Centerville, Ohio, United States, 45459
      • Cincinnati, Ohio, United States, 45219
        • Recruiting
        • University of Cincinnati
        • Principal Investigator:
          • Hani Kushlaf
        • Contact:
    • South Carolina
      • Charleston, South Carolina, United States, 29406
    • Tennessee
      • Chattanooga, Tennessee, United States, 37403
    • Texas
      • Dallas, Texas, United States, 75246
        • Recruiting
        • Baylor Scott & White Research Institute - Baylor Scott & White Research Institute
        • Contact:
        • Principal Investigator:
          • Niloofar Yari
      • El Paso, Texas, United States, 79912
      • McKinney, Texas, United States, 75071
        • Recruiting
        • Baylor Scott & White Neurology - McKinney
        • Contact:
        • Principal Investigator:
          • Francy Shu
    • Vermont
      • Burlington, Vermont, United States, 05401
        • Recruiting
        • The University of Vermont Medical Center
        • Contact:
        • Principal Investigator:
          • Rup Tandan
    • Virginia
      • Falls Church, Virginia, United States, 22043
        • Active, not recruiting
        • Integrated Neurology Services - Dr. Simon Fishman's Office

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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 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

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 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Sequential Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo

DBPC Period: Participants will be administered with Placebo, orally as 2 separate treatment courses starting on Day 1 and at the beginning of Week 5.

BE Period: Participants initially randomized to placebo matched to cladribine in DBPC period will receive cladribine Low Dose or High Dose, orally as 2 separate treatment courses starting at the beginning of Week 25 and at the beginning of Week 29 and retreated if clinically justified with placebo matched to cladribine.

RT Period: If clinically justified, participants requiring retreatment with cladribine Low Dose or High Dose or cladribine supplemental dose will receive the selected dose of cladribine or matching placebo regimen.
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.
Experimental: Cladribine Low Dose

DBPC Period: Participants will be administered with cladribine Low Dose, orally as 2 separate treatment courses starting on Day 1 and at the beginning of Week 5.

BE Period: Participants initially randomized to cladribine Low Dose in DBPC period will receive placebo matched to cladribine as 2 separate treatment courses starting at the beginning of Week 25 and at the beginning of Week 29 and retreated with cladribine supplemental dose if clinically justified.

RT Period: If clinically justified, participants requiring retreatment with cladribine Low Dose regimen and/or supplemental dose will receive the selected dose of cladribine or matching placebo regimen.
Drug: Cladribine Low Dose
Participants will receive cladribine low dose in two courses separated by 4 weeks.
Experimental: Cladribine High Dose

DBPC Period: Participants will be administered cladribine High Dose, orally as 2 separate treatment courses starting on Day 1 and at the beginning of Week 5.

BE Period: Participants initially randomized to cladribine High Dose in DBPC period will receive placebo matched to cladribine as 2 separate treatment courses starting at the beginning of Week 25 and at the beginning of Week 29 and retreated with cladribine supplemental dose if clinically justified.

RT Period: If clinically justified, participants requiring retreatment with cladribine High Dose regimen and/or supplemental dose will receive the selected dose of cladribine or matching placebo regimen.
Drug: Cladribine High Dose
Participants will receive cladribine high dose in two courses separated by 4 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
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
Baseline, Week 24

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from Baseline in Quantitative Myasthenia Gravis (QMG) Scale Score at Week 24 During the Double-Blind Placebo Controlled (DBPC) Period
Time Frame: Baseline, Week 24
Baseline, Week 24
Change from Baseline in Myasthenia Gravis Composite (MGC) Scale Score at Week 24 During the Double-Blind Placebo Controlled (DBPC) Period
Time Frame: Baseline, Week 24
Baseline, Week 24
Number of Participants With Adverse Events (AEs) and Adverse Events of Special Interest (AESIs)
Time Frame: Up to End of Study (Week 144)
Up to End of Study (Week 144)
Number of participants with Adverse Events (AEs) by Severity as per National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0
Time Frame: Up to End of Study (Week 144)
Up to End of Study (Week 144)
Number of Participants with Abnormal Laboratory Variables including Absolute Lymphocyte Count and Vital Signs
Time Frame: Up to End of Study (Week 144)
Up to End of Study (Week 144)
Pharmacokinetic (PK) Plasma Concentration of Cladribine
Time Frame: Pre-dose, 0.25, 1, 2, 3, 4, 6, 8 and 24 hours post-dose
Pre-dose, 0.25, 1, 2, 3, 4, 6, 8 and 24 hours post-dose
Change from Baseline in the Revised Myasthenia Gravis Quality of Life - 15 Scale (MG-Qol15r) Score at Week 24 During the Double-Blind Placebo Controlled (DBPC) Period
Time Frame: Baseline, Week 24
Baseline, Week 24
Percentage of MG-ADL Responders at Week 24 During the Double-Blind Placebo Controlled (DBPC) Period
Time Frame: At Week 24
MG-ADL responder is defined by achieving >= 3 points decrease in MG-ADL score.
At Week 24
Percentage of Quantitative Myasthenia Gravis (QMG) Scale Responders at Week 24 During the Double-Blind Placebo Controlled (DBPC) Period
Time Frame: At Week 24
QMG responder is defined by achieving >= 4 points decrease in QMG score.
At Week 24
Time From Initial Cladribine Full Dose Treatment to First Retreatment or Rescue Treatment up to end of Study
Time Frame: Up to End of Study (Week 144)
Up to End of Study (Week 144)
Number of Participants with Abnormal ECG parameters
Time Frame: Up to End of Study (Week 144)
Up to End of Study (Week 144)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

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

Collaborators

EMD Serono Research & Development Institute, Inc.

Investigators

  • Study Director: Medical Responsible, EMD Serono Research & Development Institute, Inc.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 25, 2024

Primary Completion (Estimated)

August 23, 2028

Study Completion (Estimated)

November 12, 2030

Study Registration Dates

First Submitted

June 11, 2024

First Submitted That Met QC Criteria

June 14, 2024

First Posted (Actual)

June 18, 2024

Study Record Updates

Last Update Posted (Actual)

May 22, 2026

Last Update Submitted That Met QC Criteria

May 19, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MS700568_0183
  • 2023-507746-83-00 (Other Identifier: EU CTIS)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

We are committed to enhancing public health through responsible sharing of clinical trial data. Following approval of a new product or a new indication for an approved product in both the US and European Union, the study sponsor and/or its affiliated companies will share study protocols, anonymized patient data and study level data, and redacted clinical study reports with qualified scientific and medical researchers, upon request, as necessary for conducting legitimate research. Further information on how to request data can be found on our website bit.ly/IPD21

IPD Sharing Time Frame

Within six months after the approval of a new product or a new indication for an approved product in both the United States and the European Union

IPD Sharing Access Criteria

Qualified scientific and medical researchers can request the data. Such requests must be submitted in writing to the company's portal and will be internally reviewed regarding criteria for researchers' qualification and legitimacy of the research proposal.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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