Background/Purpose: Previous studies have suggested that concomitant methotrexate therapy may increase the efficacy of biologic treatments. A scarcity of data exists on the benefits of combination therapy with golimumab (GLM) and MTX as well as other DMARDs (oDMARDs). The aim of this analysis was to compare the long-term retention of GLM monotherapy vs. combination therapy with MTX and/or oDMARDs and to explore independent predictors of retention in patients with rheumatoid arthritis (RA) and psoriatic arthritis followed in Canadian routine practice. 

Methods: BioTRAC is an ongoing, prospective registry of patients initiating treatment with infliximab or GLM for RA, ankylosing spondylitis, or PsA, or with ustekinumab for PsA. Eligible participants for this analysis included RA and PsA patients treated with GLM. Patients were excluded if they had follow-up <24 months and were not discontinued. Treatment durability was assessed with the Kaplan Meier (KM) estimator of the survival function and Cox regression.

Results: A total of 336 RA patients were included; baseline characteristics and disease parameters are summarized by treatment group in Table 1.  There were 195 (58.0%) patients who discontinued with a KM-based mean (SE) time to discontinuation of 36.2 (1.7) months. Between group differences were observed with higher treatment durability for MTX+GLM+oDMARDs [39.8 (2.3)] months, followed by MTX+GLM [37.4 (3.4)], GLM+oDMARDs [27.2 (4.8)] and GLM monotherapy with [25.2 (3.0)] (p=0.025). Upon adjusting for potential confounders, higher durability was observed for the MTX+GLM+oDMARDs group vs. GLM monotherapy [hazard ratio -HR- (95% CI): 0.59 (0.36-0.96), p=0.032]. Moreover, increased baseline DAS28 [HR (95% CI): 1.17 (1.03-1.32), p=0.014] and previous use of MTX [HR (95% CI): 1.73 (1.00-3.00), p=0.052], were independently associated with premature treatment termination.

A total of 167 PsA patients were included; baseline characteristics and disease parameters are described by treatment group in Table 1. There were 96 (57.5%) patients who discontinued with a KM-based mean (SE) time to discontinuation of 34.7 (2.3) months. No between group differences were observed for treatment durability. However, upon adjusting for potential confounders, increased baseline MDGA [HR (95% CI): 1.12 (1.01-1.25), p=0.038], previous use of MTX [HR (95% CI): 3.54 (1.09-11.45), p=0.035], and female gender [HR (95% CI): 1.96 (1.19-3.21), p=0.008] were independently associated with premature treatment termination.

Conclusion: The results of this analysis have shown that combination therapy with GLM, MTX and other DMARDs is significantly associated with higher treatment durability compared to GLM monotherapy among RA patients.  Although gender and MDGA were identified as significant independent predictors of long-term retention among PsA patients, treatment durability was not affected by concomitant MTX and DMARD use.