Metformin Treatment in Progressive Multiple Sclerosis

This will be a single site 1:1 randomized, placebo controlled trial of metformin treatment vs matching placebo in 44 men and women with primary progressive multiple sclerosis and secondary multiple sclerosis, without diabetes, not treated with metformin aged 30-65. The trial will last 12 months and have 3 study visits, baseline, 6 months, and 12 months. The trial will be preceded by a screening period. Over the initial 30 day titration period subjects will be titrated from 500 mg a day to 2,000 mg of metformin in increments of 500 mg every 10 days. Patients will remain on their tolerated dose and included in analysis on an intent to treat basis. Brain MRI, cognitive testing and clinical measures will be collected at baseline, month 6 and month 12. OCT will be collected at baseline and month 12. The primary outcomes are the following safety outcomes: 1) number of patients with adverse events 2) number of patients with laboratory abnormalities 3) number of patients with new T2 lesions on MRI. The secondary outcomes include reduction in localized cortical thinning on brain MRI; reduction in thalamic atrophy on brain MRI. Further exploratory outcomes include 1) improvement in SDMT-oral score, 2) improvement in CVLT-II score, 3) improvement in PACC score 4) improvement in PASAT score. Exploratory outcomes include 1) Decrease in plasma neurofilament light chain levels, 2) Reginal nerve fiber layer preservation on OCT, 3) Ganglion cell inner plexiform layer preservation, and 4) Percentage of phase rim lesions.