Objective.Previous studies combining biologic disease-modifying antirheumatic drugs (bDMARD) to treat rheumatoid arthritis (RA) have shown an increased risk of infection. However, the risk of infection with concurrent use of denosumab, a biologic agent for the treatment of osteoporosis, and a bDMARD remains unclear. Here, we evaluated the incidence of serious and opportunistic infections in patients treated concurrently with denosumab and a bDMARD and patients treated with a bDMARD alone.Methods.A chart review of patients with RA from 2 Canadian rheumatology practices between July 1, 2010, and July 31, 2014, identified 2 groups of patients: those taking denosumab and a bDMARD concurrently (concurrent group) and those taking only a bDMARD (biologic-alone group). Patients were followed from the time of initiation of denosumab, or a matched index date for the biologic-alone group, to the end of the study or loss to followup. Instances of serious or opportunistic infections were recorded.Results.A total of 308 patients (n = 102 for the concurrent group and n = 206 for the biologic-alone group) were evaluated. Within the concurrent group, 3 serious infection events occurred. Within the biologic-alone group, 4 serious infection events and 1 opportunistic infection event occurred. In both groups, all patients with serious or opportunistic infection recovered, and there were no instances of death during the study period.Conclusion.This study demonstrated a low occurrence of serious and opportunistic infections in patients with RA taking bDMARD, including patients with concurrent denosumab use.

Abstract

BackgroundStudies combining immunosuppressive biologics have shown an increased risk of infections.ObjectivesExamine the occurrence of serious and opportunistic infections in RA patients treated concurrently with DMAb and an immunosuppressive biologic, and those treated with only an immunosuppressive biologic.MethodsWe reviewed RA patients from two rheumatology practices in Ontario (Canada) between 01July2010 and 31July2014. Eligible patients were ≥18 years of age with RA, registered in the practice ≥3 months before and after the index date, and received ≥1 injection/infusion or filled a prescription for an immunosuppressive biologic therapy for RA. Patients with HIV or AIDS, or who were receiving cancer treatment or immunosuppressive therapies for conditions other than RA or living in a nursing home were excluded. The incidence of serious infections was counted for two different groups: 1) those who had used DMAb and an immunosuppressive biologic concurrently and 2) those who had used an immunosuppressive biologic alone. Serious infection was defined as resulting in hospitalization or an emergency room (ER) visit with associated use of IV antibiotics and a primary diagnosis of infection. The observational period was from the index date to 31July2014 or loss to follow-up, whichever came first. For the concurrent group, index date was defined as their first DMAb injection. A frequency-matching technique utilizing the index date of the concurrent group was used to select the index date of the biologic-alone group.Results308 patients met the eligibility criteria; patient characteristics (± 6 months of index event) are shown below. Three events of serious infection occurred in three patients in the concurrent group (all three were cases of pneumonia); four events of serious infection occurred in four patients in the biologic-alone group (three cases of pneumonia, one upper respiratory tract infection, all resulting in hospitalization). One event of opportunistic infection (mycobacterium avium complex and pleural infection) occurred in the biologic-alone group. All patients recovered, with no instances of death.Patient characteristicsConcurrent (N=102)Biologic-alone (N=206)Women, n (%)90 (88)158 (77)Age, years66.4 (10.8)57.4 (11.6)Average follow-up time, years2.4 (1.2)2.5 (1.3)History of fracture, n (%)8 (8)4 (3)T-score ≤−2.5 at the spine or hip, n (%)45 (47)23 (13)Chronic kidney disease, n (%)1 (1)4 (2)Chronic obstructive pulmonary disease, n (%)4 (4)16 (8)Cardiovascular disease, n (%)7 (7)19 (9)Diabetes, n (%)8 (8)25 (12)Liver disease, n (%)1 (1)1 (0.5)Prednisone use, % (n)21 (21)15 (7)C-reactive protein, mg/L4.6 (6.8)4.5 (8.0)Erythrocyte sedimentation rate, mm/h19.0 (17.0)17.2 (15.2)Data are means (SD) unless otherwise noted.ConclusionsRA patients may require treatment for bone loss due to intrinsic disease, steroid use, and advancing age. This study demonstrates a low occurrence of serious infections in biologically-treated RA patients, including patients with concurrent DMAb use.AcknowledgementStudy funded by Amge...