Medicinal Chemistry of Multiple Sclerosis: Focus on Cladribine

Background: In the recent years, many novel Disease-Modifying Drugs (DMD) have been introduced to the market in the treatment of multiple sclerosis. Objectives: To provide the reader with an up to date, compact review on the pharmacokinetic properties, mechanism of action, and clinical attributes of one of the most recently approved drugs in the therapy of multiple sclerosis, cladribine. Conclusion: Cladribine tablets proved to be a highly efficient treatment choice for Relapsing- Remitting Multiple Sclerosis (RRMS), especially for patients with high disease activity. It is the first DMD for MS with a complex mechanism of action, by inhibiting the adenosine-deaminase enzyme it increases the intracellular levels of deoxyadenosine triphosphate, which with relative selectivity depletes both T- and B-cells lines simultaneously. However long term follow-up safety and effectiveness data are still missing, and clear treatment protocols are lacking beyond the first two treatment years cladribine should prove to be a valuable addition to the therapeutic palette of RRMS, and potentially for Clinically Isolated Syndrome (CIS) as well.