Use of Indipamide to reduce progression of disability in people with primary and secondary progressive multiple sclerosis (MS).

Treatment tested

• Indapamide

  Thiazide-sensitive sodium-chloride cotransporter inhibitor

Inclusion: - Written informed consent obtained - Aged between 18 and 65 years - Diagnosed with PPMS or SPMS, according to current diagnostic criteria - Screening Expanded Disability Status Scale score between 4.0 and 6.5 inclusive - Screening timed 25 foot walk (average of two trials) of 5 seconds or more for people with PPMS, or of 9 seconds or more for people with SPMS - Use of effective methods of contraception for women of childbearing potential Exclusion: - Individuals with renal insufficiency and an eGFR below 30ml/min per 1.73 m2 - Individuals who start Baclofen or Tizanidine during the trial - Individuals who increase the dose of Baclofen or Tizanidine during the trial - Individuals who receive treatment with Botulinum toxin in the leg muscles during the trial - Individuals who use siponimod, ocrelizumab, natalizumab or other disease-modifying treatment for RRMS - Individuals with recent gadolinium enhancement or new T2 lesions on brain/spinal cord MRI in the 6 months prior to inclusion - Concomitant use of corticosteroids - Individuals with significant hepatic impairment (pre-existing or developing during the trial) - Individuals with clinically significant abnormal screening labs - Individuals with cardiac arrhythmia - Individuals with a prolonged QT interval: individuals with frequency corrected QT (QTc) intervals of more than 450ms (men) or 470ms (women) at the screening examination will not be included in the study, and participants with QTc intervals of greater than 500ms on any of the other ECG examinations throughout the study will be excluded from the study. - Individuals who are pregnant or currently breast-feeding - Individuals with an allergy or other intolerability to indapamide - Individuals who use Fampridine or 4-aminopyridine - Individuals who start Fampridine or 4-aminopyridine during the trial

To demonstrate non-futility of indapamide treatment for the prevention of disability worsening in PPMS and SPMS