Oral Guanabenz for Multiple Sclerosis

OBJECTIVE: This Phase 1 clinical study will aim to determine whether therapeutically adequate dosages of guanabenz are safe and well tolerated in patients with multiple sclerosis (MS). It will further provide pharmacokinetic data important for determination of optimal dosing schedule for possible future Phase 2 study. STUDY POPULATION: Six patients, ages between 18-55 inclusive, and diagnosis of definite multiple sclerosis by 2010 Revised McDonald Diagnostic Criteria (Polman et al, 2010) will be enrolled. All patients will have been on treatment with glatiramer acetate, a Food and Drug Administration (FDA) approved disease-modifying therapy, for a minimum of year. Four of the patients will be clinically stable with no clinical relapse in the preceding year and no evidence of active inflammation by MRI during the 2-month screening period; 2 patients will be selected based on evidence of on-going, active inflammation seen by MRI during the screening period. DESIGN: In this open-label, single site, dose escalation study, the maximum tolerated dose (MTD) of guanabenz in MS patients will be determined. Patients will be screened for participation under the existing MS natural history study 89-N-0045. Sequential patient enrollment will be spaced at least 6 weeks apart. Five study drug doses will be explored: 4mg, 8mg, 16mg, 32mg and 64mg. Dose escalation will ensue if the preceding dose is tolerated, defined both by patient-reported outcomes and objective clinical and imaging assessments. Patients will be maintained on lower doses (4mg-16mg) for 14 days and on higher doses (32 and 64mg) for 28 days. OUTCOMES: The primary outcome is MTD, defined as the maximum dose that produces dose-limiting toxicity (DLT) in at most 2 out of the 6 participants. Secondary outcomes include patient-reported outcomes, objective clinical and imaging assessments at 32mg and 64mg, and pharmacokinetics.