A Placebo Controlled Trial of Dalfampridine ER for Ambulatory Activity in People With Multiple Sclerosis

This is a parallel-group, double-blind, randomized controlled crossover trial with a 1:1 randomization. There are two treatment periods of 4 weeks and a two-week off treatment washout period. Treatment periods are DER (dalfampridine ER) followed by placebo (group A) and placebo followed by DER (group B), respectively. All dosages will be administered twice a week. Purpose of the study is to see if using the study drug(dalfampridine Er) for a short period of time will improve the way subjects with multiple sclerosis (MS) walk.

Inclusion criteria

• Diagnosis of MS made at least 3 months prior to based McDonald or Proser criteria.
• Age 18-75 years old inclusive.
• Expanded Disability Status Scale (EDS) 0-6.5
• Clinical stability defined as no MS exacerbation or change in disease modifying therapy for 60 days prior to screening.
• Screening 6-minute walking test distance between 50m-500m, inclusive.
• Written informed consent.

Exclusion criteria

• use of 4-aminopyridine within 6 months of screening
• Any contraindication to DER:

• Allergy to DER
• history of seizure disorder or history of EEG showing epileptiform activity
• Renal insufficiency (estimated GFR < 60.
• Any condition that would exclude 6 minute walking testing:

• Cardiac surgery or myocardial infarction within the last 3 months.
• Severe aortic stenosis or hypertropic cardiomyopathy.
• Pulmonary embolus or infarction in the last 6 months.
• Uncontrolled hypertension by history or by screening or baseline diastolic blood pressure > 170, or systolic blood pressure > 105.
• Use of oxygen at home for 24 hours/day or severe lung disease.
• History of ventricular arrhythmia or finding of significant ventricular arrhythmia. atrial arrhythmia or 2nd or 3rd degree heart block on screening ECG.
• Concomitant neurological disease, such as ALS, Parkinson Disease, stroke.
• Hospitalization in the last 6 months for psychiatric illness.
• Alcohol or drug abuse within the past year.
• Females who are breast-feeding, pregnant or have potential to become pregnant during the course of the study( fertile and unwilling/unable to use effective contraceptive measures)
• Cognitive deficits that would interfere with the subject's ability to give informed consent or preform study testing.
• Any other serious and/or unstable medical condition.
• Use of mitoxantrone (Novantrone) within 6 months of baseline visit.