Probability of achieving bone mineral density treatment targets with abaloparatide and teriparatide

The goal of treatment for women at high risk of fracture who have a T-score ≤-2.5 is to mitigate fracture risk by achieving T-scores at least above -2.5. In the ACTIVE trial, 2463 women with osteoporosis aged 49-86 yr were treated for 18 mo with abaloparatide (80 μg), teriparatide (20 μg), or placebo. In ACTIVExtend, eligible women from the abaloparatide and placebo groups received weekly treatment with 70 mg of alendronate for 2 additional years. This post hoc analysis of ACTIVE and ACTIVExtend included women with baseline TH or LS T-scores ≤-2.5. Logistic regression was used to predict the probability of achieving a T-score >-2.5 at the TH or LS during 18 mo of treatment with abaloparatide or teriparatide and during 3.5 yr with the sequence of abaloparatide/alendronate compared to placebo/alendronate. At baseline, 23% and 74% of women enrolled in ACTIVE had T-scores ≤-2.5 at the TH and LS, respectively. Over 18 mo of treatment, more than 50% of women were likely to achieve TH T-scores >-2.5, with baseline TH T-scores as low as -2.7 for both abaloparatide and teriparatide. More than 50% of women were predicted to achieve an LS T-score >-2.5 with a baseline LS T-score as low as -3.3 for abaloparatide or -3.2 on teriparatide. Over 3.5 yr of sequential treatment with abaloparatide/alendronate, >50% of women with baseline TH T-scores ≥-2.9 and LS T-scores ≥-3.5 were predicted to achieve T-scores >-2.5, respectively. A patient's BMD at baseline and the probability of achieving target T-scores with treatment should be considered when determining that treatment should be initiated in patients at high or very high risk of fracture.