Leflunomide in psoriatic arthritis: a retrospective study of discontinuation rate in daily clinical practice compared with methotrexate.

OBJECTIVE

To assess the safety profile of leflunomide (LEF) in a two-year retrospective analysis of psoriatic arthritis (PsA) patients (pts) treated in daily clinical practice compared with methotrexate (MTX).

PATIENTS

Fourty-two PsA patients with polyarticular involvement or asymmetrical oligoarticular arthritis, satisfying ESSG criteria for the spondyloarthropathies, treated with LEF monotherapy (10-20mg/die without loading dose) between September, 2004 and August, 2006 were reviewed. They were compared with MTX (7.5-15mg/week) users (44 cases). The adverse events (AEs) and the causes of withdrawal were evaluated.

RESULTS

At 24 months, cumulative survival rate of pts remaining on drugs was 54.9% in LEF users and 57.0% in MTX users (p > 0.05). The discontinuation rate (DR) for toxicity was higher in LEF group (29.2%) than in MTX group (10.8%) (p = 0.07). The occurrence of AEs was more frequently registered in the first year in both groups. LEF monotherapy showed a significant higher crude incidence for any AEs (38.7 events x100 person-years) compared to MTX (14.3 events x100 person-years) (p < 0.001). The cumulative DR for inefficacy was greater but not statistically significant in MTX group than LEF (28.6% vs. 12.6% respectively; p = 0.056). Finally, DR for other causes accounted for 8.7% vs. 11.0% respectively (p > 0.05).

CONCLUSIONS

Our data showed, in a setting of clinical practice, that the rate of PsA pts remaining on drug was comparable between LEF and MTX, and a manageable LEF safety profile during a 24 months of follow-up, even if a greater incidence of DR for AEs was registered than in MTX users.