Efficacy of once-weekly and twice-weekly injections of teriparatide by patient characteristics: A post hoc analysis of the TWICE study

OBJECTIVES: To assess differences in efficacy of a 28.2-μg teriparatide formulation for twice-weekly use (2/W-TPTD) by patient characteristics. METHODS: A post hoc analysis was performed using data from a multicenter, randomized, double-blind, double-dummy, non-inferiority trial (TWICE study) conducted in Japan comparing the efficacies of once-weekly and twice-weekly injections of teriparatide (TPTD). Specifically, a stratified analysis of percentage changes from baseline was performed using the final data on lumbar spine bone mineral density (BMD) after a 48-week treatment period (n = 251, 2/W-TPTD; n = 239, a 56.5-μg teriparatide formulation for once-weekly use [1/W-TPTD]). RESULTS: Across all subgroups defined by patient characteristics that included 9 or more subjects, the lumbar spine BMD increased significantly in both groups. In the 2/W-TPTD group, the percentage change was significantly higher in subjects with no non-vertebral fractures without large external force occurring at or after age 50 years versus those with such fractures. The lower the stratification in baseline lumbar spine BMD, total hip BMD, or femoral neck BMD, the greater was the percentage change. CONCLUSIONS: Whereas all subgroups can expect a significant improvement in lumbar spine BMD, there were some patient characteristics that affected the percentage increase in BMD.