Effects of Teriparatide on Joint Erosions in Rheumatoid Arthritis: A Randomized Controlled Trial

Objective Articular erosions correlate with disability in rheumatoid arthritis (RA). Biologic agents reduce erosion progression in RA, but erosion healing occurs infrequently. This study was undertaken to assess the effects of the anabolic agent teriparatide on joint erosion volume in RA patients treated with a tumor necrosis factor inhibitor (TNFi). Methods We conducted a randomized controlled trial in 24 patients with erosive RA, osteopenia, and disease activity controlled by TNFi treatment for at least 3 months. Half were randomized to receive teriparatide for 1 year and the others constituted a wait-list control group. Subjects and primary rheumatologists were not blinded with regard to treatment assignment, but all outcomes were assessed in a blinded manner. The primary outcome measure was change in erosion volume determined by computed tomography at 6 anatomic sites. Significance within each hand and anatomic site was based on a 2-tailed test, with P values less than 0.05 considered significant. Results Baseline characteristics of the treatment groups were well balanced. After 52 weeks, the median change in erosion volume in the teriparatide group was −0.4 mm3 (interquartile range [IQR] −34.5, 29.6) and did not differ significantly from that in controls (median change +9.1 mm3 [IQR −29.6, 26.4]) (P = 0.28). No significant difference in change in erosion volume was noted at the radius, ulna, or metacarpophalangeal joints. Bone mineral density improved at the femoral neck and lumbar spine in the teriparatide group. Conclusion Our findings indicate that teriparatide treatment for 1 year does not significantly reduce erosion volume in the hands or wrists of patients with established RA with disease activity controlled by TNFi treatment.