Teriparatide for treatment of patients with bisphosphonate-associated atypical fracture of the femur.

Abstract

Little clinical data are available on the use of teriparatide for the treatment of bisphosphonate-associated atypical femur fractures (AFF). The goal of the Fix-IT study was to determine if immediate therapy with teriparatide was superior for fracture healing after an AFF compared to a 6-month delay in teriparatide therapy. This randomized pilot clinical trial included 13 women with an AFF who were randomized to immediate teriparatide vs a delay of 6months. All were followed for 12months on teriparatide. The primary outcomes included individual and composite measures of radiologic bone healing (scored 1 point [no healing] to 4 points [complete healing]) at 6 and 12months. Secondary outcomes included bone mineral density of the unfractured contralateral hip, spine, 1/3 distal radius, and adverse events. We found there was a trend for superior healing with the composite score (12.6 vs 11.2 at 6months and 15.4 vs 13.2 at 12months), and lesser bone mineral density declines at the 1/3 distal radius (12-month change -1.9 vs -6.1%) in the immediate vs the delayed group. There were no differences in adverse events. There was one implant failure in the delayed group. There is a preliminary signal for greater improvements with immediate teriparatide therapy vs delayed therapy. However, because an AFF is a rare event, and only a small number of patients were included, the results must be interpreted with caution.