Treatment Satisfaction in Postmenopausal Women Previously Treated with Bisphosphonates Who Transitioned to Denosumab Vs Ibandronate Therapy in an Open-Label Study

Background/Purpose: Higher treatment satisfaction is associated with greater persistence with osteoporosis therapy in postmenopausal women (Barrett-Connor OI 2012). Greater satisfaction has been reported with subcutaneous injections of denosumab compared with oral alendronate tablets in a randomized, cross-over study where subjects received both treatments (Freemantle OI 2012). In this open-label trial, we evaluated treatment satisfaction in postmenopausal women with low bone mineral density (BMD) who were sub-optimally treated with prior bisphosphonate therapy and were transitioned to denosumab or ibandronate. Methods: This was a multicenter, randomized, open-label, parallel-group study in which postmenopausal women aged 55 and older were randomized 1:1 to receive open-label denosumab 60 mg subcutaneously every 6 months or ibandronate 150 mg orally every month for 12 months. The treatment satisfaction questionnaire for medication (TSQM) version 1.4 was given at baseline and months 6 and 12 or at time of early termination. TSQM is a validated tool that measures the subject’s perception of the 4 domains of treatment satisfaction: the medication’s effectiveness, convenience, side effects, and global satisfaction (Atkinson Health Qual Life Outcomes 2004). Each TSQM domain score is between 0 and 100 and a higher score indicates a more preferred health status. Treatment comparisons of change in TSQM from baseline to months 6 and 12 were analyzed using an ANCOVA model fitted with treatment group and adjusted for baseline TSQM domain score. Results: The study population included 833 women (417 denosumab; 416 ibandronate) with a mean (SD) age of 66.7 (8.0) years and mean (SD) BMD T-scores of –1.8 (0.7) at the total hip, 2.1 (0.7) at the femoral neck, and –2.5 (0.8) at the lumbar spine. Compared with the TSQM scores at baseline, subjects in both treatment groups reported greater satisfaction in all domains of the TSQM at month 6 and at month 12. However, subjects who transitioned to denosumab therapy had significantly greater improvements among all domains than did subjects who transitioned to ibandronate therapy at month 6 (P 0.0004 in all domains; data not shown) and at month 12 (P 0.0003 in all domains; Table 1).Table 1. TSQM Change From Baseline to Month 12 TSQM Domain Treatment n LS Mean 95% CI P-value* Effectiveness Ibandronate 332 17.9 15.6, 20.2 0.0001 Denosumab 378 24.1 22.0, 26.3 Convenience Ibandronate 338 16.7 14.9, 18.6 0.0001 Denosumab 384 26.3 24.6, 28.0 Side Effects Ibandronate 337 4.2 2.7, 5.8 0.0003 Denosumab 385 8.1 6.7, 9.6 Global Satisfaction Ibandronate 337 14.9 12.8, 17.1 0.0001 Denosumab 382 26.4 24.4, 28.4 n number of subjects with non-missing TSQM domain at baseline and at month 12. LS least squares. CI confidence interval. *P-value from treatment comparison based on an ANCOVA model fitted with treatment group and adjusted for baseline TSQM domain score. Conclusion: In summary, postmenopausal women with low BMD who were sub-optimally treated with prior bisphosphonate therapy reported greater satisfaction if they transitioned to denosumab vs ibandronate in an open-label study. Greater treatment satisfaction may lead to better adherence to therapy and thus improvements in treatment efficacy