Efficacy

Efficacy of Mayzent (Siponimod) in Treating Multiple Sclerosis

Mayzent (Siponimod) is an oral medication approved by the Food and Drug Administration (FDA) for the treatment of adults with relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease. Clinical trials have demonstrated that Siponimod is effective in reducing the frequency of relapses and delaying the progression of disability associated with MS. The pivotal Phase III trial, EXPAND, showed that Siponimod reduced the risk of three-month confirmed disability progression by 21% compared to placebo. Additionally, the annualized relapse rate was significantly lower in patients treated with Siponimod compared to those on placebo.

Mayzent works by modulating the activity of certain types of immune cells, known as sphingosine 1-phosphate (S1P) receptors. By binding to these receptors, Siponimod sequesters lymphocytes in lymph nodes, preventing them from contributing to the autoimmune attack on the myelin sheath of nerve fibers in the central nervous system, which is a hallmark of MS. This mechanism of action helps to reduce the inflammatory activity and demyelination in the nervous system, thereby mitigating the progression of the disease.

Efficacy of Tysabri (Natalizumab) in Treating Multiple Sclerosis

Tysabri (Natalizumab), with the biosimilar Natalizumab-sztn, is a monoclonal antibody administered via intravenous infusion and is approved for the treatment of relapsing forms of multiple sclerosis. Tysabri has been shown to be highly effective in reducing the frequency of clinical exacerbations and in delaying the accumulation of physical disability. In the AFFIRM and SENTINEL clinical trials, Tysabri demonstrated a 68% relative reduction in the annualized relapse rate over two years compared to placebo. Moreover, the risk of sustained progression of disability was reduced by 42-54% over the same period.

Tysabri's mechanism of action involves the inhibition of the movement of potentially damaging immune cells from the bloodstream, across the blood-brain barrier, into the brain and spinal cord. This action reduces the immune-mediated attack on the central nervous system. Due to its efficacy, Tysabri is often considered for patients with highly active relapsing MS or for those who have not responded adequately to other treatments. However, it is important to note that Tysabri is associated with an increased risk of progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection, which necessitates careful patient selection and monitoring.