Background/Purpose: It has is been demonstrated the safety and efficacy of Methotrexate (MTX) in the treatment of Giant Cell Arteritis (GCA) in clinical trials, but it is important to know the long-term survival of the drug in real life conditions. The purpose of our study was  to analyze, in clinical practice conditions, the long-term survival of MTX in patients with GCA. Factors associated to its discontinuation rate were also investigated.

Methods: This is an observational longitudinal study with a maximum follow-up of 20 years. We included GCA patients treated with MTX and followed in outpatient clinic at Hospital Clínico San Carlos, in Madrid from January 1991 until September 2014. Primary outcome: discontinuation of MTX due to: a) adverse drug reaction (ADR), (classified as moderate when the drug was suspended regardless of the impact, and severe when ADR required hospitalization or death); b) inefficacy; c) improvement or remission; and d) patient decision. Covariables analized were: sociodemographic, clinicals and therapy. Incidence rates of MTX discontinuation (IR) per 100 patient-years with their respective 95% confidence interval [95% CI] were estimated using survival techniques. Associated factors to discontinuation were run by Cox regression models.

Results: Eighty two patients with 96 courses of MTX therapy (168.3 patient-years) were included. They were mostly women (75.6%), the mean age at diagnosis was 76.7±7.3 years. The IR of MTX discontinuation was estimated in 38.6 [30.2-49.2]. The IR due to ADR was 21.3[15.4-29.6] most of them infections and not severe (IR if severe ADR: 6.6 [1.6-7.9]). The IR of discontinuation due to improvement was 11.9 [7, 7-18.42] and the IR due to inefficacy was 1.8 [0.6-5.5]. In the multivariate analysis for risk of discontinuation due to inefficacy, the number of relapses was associated to higher risk to discontinuation whereas elevated ESR and higher average doses of corticosteroids had less risk of discontinuation. In the final model for discontinuation due to ADRs, age at diagnosis, male, visual disturbances, cardiovascular and general symptoms at diagnosis had higher risk of discontinuation. However, treatment with MTX at diagnosis had a lower risk of suspension for ADRs. The independent factors that influenced the suspension due to improvement were fewer recurrences during the follow-up and the younger the age at onset of disease.

Conclusion: MTX treatment for GCA, seems safe and effective in clinical practice. A low incidence of serious adverse events, a low incidence of discontinuation due to inefficacy and a high incidence of discontinuation due to improvement or remission were observed. We have also found several sociodemographic and clinical factors that can modify its survival.

« Back to 2015 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/long-term-survival-of-methotrexate-in-giant-cell-arteritis-patients-in-clinical-practice/