Background/Purpose: Guidelines for the treatment of chronic conditions such as hypertension and diabetes include specific biomarker targets. This differs from osteoporosis treatment guidelines, which currently do not define treatment targets or goals. In general, absence of BMD loss and absence of fracture are considered treatment successes. This is far from ideal because success defined by the lack of a negative outcome does not set a real goal for therapy. Potential goals for osteoporosis treatment might include reaching a BMD T‑score value somewhere above –2.5 which represents an acceptable level of fracture risk. To provide insight into T-score values achieved over time with denosumab (DMAb), we report on the percentage of women who achieved a range of possible target BMD T-scores at both the lumbar spine and total hip over 8 years of treatment.

Methods: For these analyses, women received 3 years of DMAb (60 mg subcutaneously every 6 months) during FREEDOM and 5 years of DMAb during the Extension for a total of 8 years of continued treatment. The percentage of women with T-scores > -2.5, > -2.2, > -2.0, and > -1.8 at both the lumbar spine and total hip, and T-scores > -2.5 at either the lumbar spine or total hip at baseline and over 8 years of DMAb treatment were determined. The influence of baseline T‑score on subsequent T-score improvement was also explored.

Results: At FREEDOM baseline, mean (standard deviation) lumbar spine and total hip T-scores were -2.83 (0.67) and -1.85 (0.79), respectively, for the DMAb Extension participants (N = 2,343). The percentage of women with T‑scores > -2.5, > -2.2, > -2.0, and > -1.8 at both the lumbar spine and total hip progressively increased from baseline over 8 years of DMAb treatment as follows: 11% to 82% (> -2.5), 4% to 65% (> -2.2), 2% to 53% (> -2.0), and 1% to 39% (> -1.8) (Fig. 1). At individual sites, the percentage of women with a T‑score > –2.5 increased from baseline over 8 years of DMAb treatment from 19% to 86% (lumbar spine) and from 75% to 94% (total hip). Baseline T‑scores by quartile remained largely consistent throughout the 8 years of DMAb treatment, which showed similar trajectory in BMD across subjects regardless of initial BMD (not shown).

Conclusion: DMAb enables a substantial proportion of women with osteoporosis to achieve non-osteoporotic T‑scores. The data reported here contribute insightful information to discussions on the topic of treatment goals for osteoporosis.