Efficacy of TNF Inhibitor vs. Non-TNF Inhibitor Monotherapy Compared in RA
SAN FRANCISCO, CA—According to study results presented at the 2015 ACR/ARHP Annual Meeting, initiating non-TNF inhibitor monotherapy had similar or better efficacy compared with initiation of TNF inhibitor monotherapy in patients with rheumatoid arthritis.
For rheumatoid arthritis treatments, monotherapy comprises about 30% of biologic disease-modifying anti-rheumatic drug (DMARD) use, stated Chieh-I Chen, MPH, from Regeneron Pharmaceuticals, Tarrytown, NY. Chen and colleagues set out to evaluate the efficacy of monotherapy in patients initiating TNF inhibitors and non-TNF inhibitor biologics. They developed an algorithm to estimate the biologic efficacy "by examining claims data for biologic therapy, including adherence, dose increases, and switches, as well as claims for concomitant therapy.
Using Optum claims data from January 2009–February 2014, study authors set the index date as the date of first claim for a biologic DMARD or tofacitinib after the patient was enrolled for ≥6 months. Inclusion criteria were adults aged ≥18 years at index date, an ICD-9 diagnosis of rheumatoid arthritis pre-index or the first 30 days post-index, and monotherapy (no conventional DMARD for 120 days post-index).
New monotherapy was initiated in patients with rheumatoid arthritis with intravenous (IV) TNF inhibitors (n=246), IV non-TNF inhibitor (n=266), subcutaneous (SC) TNF inhibitor (n=1,595), SC non-TNF inhibitor (n=36), or tofacitinib (n=4). The patients' rheumatoid arthritis was considered effectively treated if the patient met the following 6 criteria post-index:
· High adherence (infusions per labeling or medication possession ratio ≥80%)
· No increase in biologic dose
· No switch to a different biologic (or tofacitinib)
· No new non-biologic DMARD
· No new or increased oral glucocorticoid
· <2 glucocorticoid injections >90 days after the index date
Study authors found that obtaining all 6 criteria for efficacy was not different between new IV or SC non-TNF inhibitor monotherapy and new IV or SC TNF inhibitor monotherapy (20.9% vs. 20.8%; P=0.947). Study patients that initiated TNF inhibitor monotherapy were more likely to increase their index biologic dose. Patients initiating IV non-TNF inhibitor monotherapy were more likely to meet all 6 criteria for efficacy (21.4% vs. 10.6%; P<0.001). In addition, higher adherence was more likely in patients initiating IV TNF inhibitor monotherapy and they were more likely to increase their biologic dose.
Chen cited that small sample sizes for SC non-TNF inhibitors (abatacept or tocilizumab) or tofacitinib may have limited interpretation of their efficacy.