Safety and Efficacy Evaluation for the Addition of Either Etanercept or Leflunomide in Korean Rheumatoid Arthritis Patients Inadequately Responding to Methotrexate

ABSTRACT

OBJECTIVE: To compare the safety and efficacy associated with the addition of etanercept (ETN) with that of leflunomide (LEF) in Korean rheumatoid arthritis (RA) patients, who inadequately respond to methotrexate (MTX) in a randomized, open-label study. METHODS: Twenty-nine subjects suffering moderate to severe RA, despite MTX treatment were randomly assigned to a combination therapy with either ETN or LEF. The primary end-point was the proportion of subjects achieving American College of Rheumatology (ACR20) criteria at week 16. RESULTS: Ninety percent (n=18) of the ETN+MTX group (n=20) and 22.2% (n=2) of the LEF+MTX group (n=9) achieved an ACR20 response (p=0.001). All patients (n=20) in the ETN+MTX group showed moderate or good EULAR response as compared with 55.6% (n=5) in the LEF+MTX group (p=0.012). All of the ETN+MTX subjects completed the study without adverse events. Adverse events occurred in 77.8% (n=7) of cases in the LEF+MTX group; significantly elevated serum AST/ALT levels in 6 subjects and mild neutropenia (ANC < 1,500/microL) in 1 subject. CONCLUSION: The ETN+MTX combination therapy was effective and safe, whereas the LEF+MTX combination therapy resulted in moderate efficacy in only half of the cases, and was accompanied by a high rate of adverse events. Elevated AST/ALT was the most common adverse event causing dose adjustment or discontinuation of therapeutic agent in the LEF+MTX group.