Leflunomide in Rheumatoid Arthritis: Factors associated with therapeutic maintenance

Introduction Leflunomide is an immunomodulator indicated for the treatment of rheumatoid arthritis (RA). Its advent coincided with the arrival of biologics, limiting the scientific community's interest in analyzing its efficacy. Our study aimed to evaluate the therapeutic maintenance of leflunomide during the treatment of RA and to analyze the possible associated factors. Methods We conducted a single-center retrospective study at a rheumatology department, including all patients with RA, according to ACR/EULAR criteria, who received leflunomide for one month and more. RA activity parameters and adverse events were collected. Results We collected 73 patients divided into 70 women and three men. The average age at the time of introduction of leflunomide was 49.77 years [23-73]. The mean duration of treatment was 12.45±11.75 months. The rate of leflunomide maintenance was 96%, 73%, 27%, 15%, 10% and 4% at three months, six months, twelve months, eighteen months, 24 months, 36 months and 48 months respectively. The incidence rate for leflunomide discontinuation was 109 per 100 patient-years with a 95% confidence interval of 101 to 116 per 100 patient-years. Reasons for discontinuation of leflunomide were mainly the occurrence of adverse events (52%) and ineffectiveness of treatment (42%). In multivariate analysis, factors associated with leflunomide maintenance were: age less than 50 years (p=0.027; HR= 1.806; 95% CI [1.071; 3.048]) and use of systemic corticosteroids at leflunomide initiation (p=0.001; HR=2.713; 95% CI [1.480; 4.978]). Conclusion Our study confirms the efficacy of leflunomide prescribed in RA. A strict control of patients is recommended to avoid adverse events leading to drug discontinuation.