Effects of Fingolimod Treatments on Alanine Transaminase and Aspartate Transaminase Levels in Patients with Multiple Sclerosis

Introduction: Multiple Sclerosis (MS) is a chronic neurological disorder with no known cause or cure. Fingolimod (FTY720) is an oral medication recently approved for the treatment of MS as well as other diseases with autoimmune aspects. However, the drug is not without side effects. The severity and prevalence of these side effects are not completely understood. One of the most common causes for the patient cessation of fingolimod is an increase in liver enzymes, indicating possible inflammation or damage to liver cells. Alanine transaminase (ALT) and aspartate transaminase (AST) are the most common liver enzymes used as indicators of hepatic health.

Objectives: This three-month prospective cohort study selected patients who were diagnosed with relapsing-remitting MS (RRMS) and who were not taking fingolimod oral treatment. ALT and AST levels were determined for these patients at baseline and then after three months of taking FTY720 to determine if these liver enzymes were changed.

Methods: 36 RRMS patients completed this study, which lasted three months. They were started on 0.5 oral FTY720 after approval from a physician and completion of an AST/ALT blood test. Baseline levels were determined and then taken again three months later. Statistical analysis of these values was performed using P<0.05 as a significance threshold.

Results: In this sample of patients, only ALT levels were significantly increased after fingolimod treatment in the general cohort (P=0.00). The general cohort showed an insignificant increase in AST levels. In male and female populations separately, AST was not significantly increased. ALT was only significantly increased in men (P=0.00) and insignificantly increased in women.

Conclusion: This study further confirms our concerns about fingolimod's possible effects on the liver. While these numbers do support the claim that the drug does on average increase ALT in patient populations, it is important to note that most of these patients have no real hepatic side effects. In addition, previous studies have cited a return to normal ALT and AST levels after cessation of fingolimod, suggesting its effects are temporary and not severely damaged in the usual patient.