Novartis’ (NVS) investigational oral, once-daily Siponimod for the treatment of secondary progressive multiple sclerosis in adults awaits the FDA decision in March.Secondary progressive multiple sclerosis is a form of multiple sclerosis that leads to progressive, irreversible disability, such as the need for enhanced walking aids and wheelchairs, bladder dysfunction and cognitive decline, largely independent of relapses.Siponimod works by binding to lymphocytes, one of the main types of immune cells, and stops them from entering the brain and spinal cord, thereby preventing them from causing inflammation and damage to the myelin sheath.If approved, Siponimod, formerly known as BAF312, would be the first oral disease-modifying therapy with the potential to delay progression and expand possibilities for secondary progressive multiple sclerosis patients.Analysts expect Siponimod to rake in blockbuster sales. The investigational drug is also under review in Europe, with a decision anticipated in late 2019.NVS closed Tuesday’s trading at $91.49, up 0.43%.