Background: Increases in bone mineral density (BMD) reduce fracture risk in patients receiving treatment for osteoporosis. Goal-directed Treatment (also called ‘Treat-to-Target’) recommends that selection of initial treatment (anti-resorptive agent or bone-forming agent) for patients with a T-score <−2.5 should be based on the probability of achieving a goal BMD T-score ≥−2.5.
Objective: To compare the probability of achieving a T-score of ≥−2.5 at the total hip or lumbar spine after 3 years treatment with ALN only; or the treatment sequence of 12 months ROMO, followed by 2 years ALN (ROMO/ALN) or DMAB (ROMO/DMAB).
Methods: Female participants in the ARCH trial received ALN for 3 years or ROMO for 1 year followed by ALN for 2 years. Those in the FRAME trial received ROMO for 1 year followed by DMAB for 2 years. For participants with initial BMD T-scores <–2.5 at total hip or spine, we calculated the probability of achieving a T-score ≥–2.5 with the three treatments.
Results: The probabilities of achieving a T-score ≥–2.5 depended on baseline T-score and treatment; see Figure 1 for details.
Conclusion: Women with a baseline T-score ≥–3.0 at the spine or ≥–2.7 at the hip have at least a 50% chance to achieve a T-score ≥–2.5 with any of the three regimens. In contrast, those with a T-score below –3.0 at the spine, or –2.7 to –3.5 at the total hip, have a substantially greater probability of achieving T-scores ≥–2.5 when using a bone-forming agent first (i.e. ROMO/ALN or ROMO/DMAB vs. ALN alone). Those with hip T-scores ≤–3.5 may require more than 3 years of treatment that continues to improve BMD. These probabilities should be considered when selecting initial treatment.