EXALT

Treatment tested

• Zoledronic acid anhydrous
• Calcium

Placebo or sham

• Placebo

Other measures (9)

Inclusion: * Written informed consent to participate in the trial * Definite diagnosis of Multiple Sclerosis (MS) as defined by 2005 revised McDonald criteria * MS-subtype: Relapsing-remitting MS (RRMS), Secondary progressive MS (SPMS), Primary progressive MS (PPMS) * Expanded Disability Status Scale (Kurtzke's scale; EDSS) score between 2.5 to 6.5 (including both) * Bone mineral density (BMD) T-score of less or equal to -2.0 and more or equal to -4.0 at the lumbar spine (L1-L4 with at least 2 evaluable vertebrae) and/or total hip region and/or femoral neck in recent Dual X-Ray Absorptiometry (DXA)-scan (\< or = 3 months) * Sufficient ability to read, write and communicate comprehensibly and comply to study procedures * No immunomodulatory treatment for MS within the last 30 days or stable and well tolerated therapy with any beta-interferon formulation, or glatirameracetate or fingolimod for at least 30 days immediately prior to baseline Exclusion criteria: * Contraindications against Calcium and Vitamin D and zoledronic acid according to the summary product characteristics * More than one osteoporotic fracture * Concomitant medication with influence on bone mineral density (eg. enzyme- inducing antiepileptics like Carbamazepin, Phenytoin, Phenobarbital, Primidon) * Any neurological disorder other than MS which is known to affect bone mineral density (e.g. muscular dystrophy, severe paresis for other reasons than MS, degenerative nervous disorder, stroke) * Women who are pregnant or breast feeding, or menstruating and capable of becoming pregnant. * Baseline renal insufficiency * 25-OH vitamin D level \< 10 ng/ml at screening * Serum calcium levels > 2.75 mmol/l (11.0 mg/dL) or \< 2.00 mmol/L (8.0 mg/dL) at screening * Other protocol-defined inclusion/exclusion criteria may apply

This study is designed to evaluate the efficacy and safety of zoledronic acid 5 mg intravenous (i.v.) relative to placebo in Multiple Sclerosis (MS) patients with osteoporosis and to support the optimal use of zoledronic acid for this indication. Primary objective is the change of Bone Mineral Density (BMD) at lumbar spine (L1-L4) and total hip region assessed by T-Score at month 12 relative to screening as measured by Dual X-ray Absorptiometry (DXA). This double-blind period will be followed by a 52-week open-label treatment phase to assess long-term efficacy and safety of zoledronic acid in these patients.