Although studies have suggested that TNF inhibitors may increase bone density, these drugs appear to be no more effective than non-biologic drugs at reducing the risk of fracture. These results were published in Arthritis Care & Research.
TNF inhibitors are biologic drugs that are commonly used in the treatment of rheumatoid arthritis (RA) and certain other autoimmune conditions. These drugs include Enbrel® (etanercept), Remicade® (infliximab), Humira® (adalimumab), Cimzia® (certolizumab), and Simponi® (golimumab).
Previous studies have suggested that TNF inhibitors may some beneficial effects on bone, but it’s been unclear whether these effects translate into a reduced risk of fracture. A reduced risk of fracture would be an important benefit because people with RA are at increased risk of fracture compared with people in the general population.
To assess fracture risk, researchers evaluated a large group of people with rheumatoid arthritis, inflammatory bowel disease, psoriasis, psoriatic arthritis, or ankylosing spondylitis. All of the study participants were starting treatment with a TNF inhibitor or a non-biologic medication; in the case of RA, the non-biologic treatments involved hydroxychloroquine, sulfasalazine, and/or leflunomide. The RA patients had previously been treated with methotrexate.
In each disease group, the frequency of fractures among people treated with a TNF inhibitor was similar to the frequency among people who were treated with a non-biologic medication. Among people with RA, a high dose of prednisone increased fracture risk.
These results suggest that TNF inhibitors are no more effective than conventional, non-biologic RA drugs at reducing fracture risk; studies with longer follow-up, however, may provide additional information.
Reference: Kawai VK, Grijalva CG, Arbogast PG et al. Initiation of Tumor Necrosis Factor α Antagonists and Risk of Fractures in Patients With Selected Rheumatic and Autoimmune Diseases. Arthritis Care & Research. 2013 Jul;65(7):1085-94.