A phase II trial examining the safety and preliminary efficacy of repetitive transcranial magnetic stimulation (rTMS) for people living with multiple sclerosis.

Background: Multiple sclerosis (MS) is a chronic neurological condition and the leading cause of non-traumatic disability in young adults. MS pathogenesis leads to the death of oligodendrocytes, demyelination, and progressive central nervous system neurodegeneration. Endogenous remyelination occurs in people with MS (PwMS) but is insufficient to repair the damage. Our preclinical studies in mice indicate that endogenous remyelination can be supported by the delivery of repetitive transcranial magnetic stimulation (rTMS). Our phase I trial concluded that 20 sessions of rTMS, delivered over 5 weeks, are safe and feasible for PwMS. This phase II trial aims to investigate the safety and preliminary efficacy of rTMS for PwMS.

Methods: Participants must be aged 18-65 years, diagnosed with MS by a neurologist, stable and relapse free for 6 months, have an Extended Disability Status Scale (EDSS) between 1.5 and 6 (inclusive), willing to travel to a study site every weekday for 4 consecutive weeks, and able to provide informed consent and access the internet. Participants from multiple centres will be randomised 2:1 (rTMS to sham) stratified by sex. The intervention will be delivered with a Magstim Rapid2 stimulator device and circular 90-mm coil or MagVenture MagPro stimulator device with C100 circular coil, positioned to stimulate a broad area including frontal and parietal cortices. For the rTMS group, pulse intensity will be set at 18% (MagVenture) or 25% (Magstim) of maximum stimulator output (MSO), and rTMS applied as intermittent theta burst stimulation (iTBS) (~ 3 min per side; 600 pulses). For the sham group, the procedure will be the same, but the intensity is set at 0%. Each participant will attend 20 intervention sessions over a maximum of 5 weeks. Outcome measures include MS Functional Composite Score (primary), Fatigue Severity Scale, Hospital Anxiety and Depression Scale, Quality of Life, and Pittsburgh Sleep Quality Index/Numeric Rating Scale and adverse events (secondary) and advanced MRI metrics (tertiary). Outcomes will be measured at baseline and after completing the intervention.

Discussion: This study will determine if rTMS can improve functional outcomes or other MS symptoms and determine whether rTMS has the potential to promote remyelination in PwMS.

Trial registration: Registered with Australian New Zealand Clinical Trials Registry, 20 January 2022; ACTRN12622000064707.