List of products in the National Drug Code with proprietary name . This medication is used to treat a certain type of multiple sclerosis (relapsing multiple sclerosis-MS). Siponimod is not a cure for MS but it is thought to help by preventing immune system cells (lymphocytes) from attacking the nerves in your brain and spinal cord. It helps decrease the number of episodes of disease worsening (relapses) and may prevent or delay disability.