Inclusion Criteria:
General
- sign written informed consent prior to participating in the study
- 25 through 65 years of age inclusive
females of childbearing potential must:
- have a negative pregnancy test at Baseline (prior to randomization) and
- use simultaneously two forms of effective contraception during the treatment and 3-months after discontinuation of study medication
Primary Progressive Multiple sclerosis.
- diagnosis of primary progressive multiple sclerosis (according to the 2005 Revised McDonald criteria):
- time since first reported symptoms between 2 and 10 years
- evidence of clinical disability progression in the 2 years prior to Screening
disability status at Screening
- EDSS score of 3.5-6.0 inclusive
- pyramidal functional system score of 2 or more
- 25'TWT less than 30 seconds
Exclusion Criteria:
PPMS specific:
- History of relapses/attacks
- Progressive neurological disorder other than PPMS
- Pure cerebellar syndrome or pure visual progressive syndrome or pure
- cognitive progressive syndrome
- Presence of spinal cord compression at screening MRI
- Relevant history of vitamin B12 deficit
- Evidence of syphilis or borreliosis at Screening
Cardiovascular conditions:
- Myocardial infarction within the past 6 months or current unstable ischemic heart disease
- History of angina pectoris due to coronary spasm or history of Raynaud's phenomenon
- Severe cardiac failure or cardiac arrest
- History of symptomatic bradycardia
- Resting pulse <55 bpm pre-dose
- History of sick sinus syndrome or sino-atrial heart block
- History or presence of second and third degree AV block or an increase QT interval (QTc>440 ms)
- Arrythmia requiring treatment with class III antiarrythmic drugs
- History of positive tilt test from workout of vasovagal syncope
- Hypertension, not controlled with medication
Pulmonary:
- Severe respiratory disease or pulmonary fibrosis
- TB
- Abnormal X-ray, suggestive of active pulmonary disease
- Abnormal PFT: <70% of predicted for FEV1 and FVC; <60% for DLCO
- Patients receiving chronic (daily) therapies for asthma
Hepatic:
- Known history of alcohol abuse, chronic liver or biliary disease
- Total or conjugated Brb >ULN, unless in context of Gilbert's syndrome
- AP >1.5xULN; ALT/AST >2xULN; GGT>3xULN
Other:
Other protocol-defined inclusion/exclusion criteria may apply.