Treatment adherence among patients with chronic conditions may be influenced by many factors, including

patient beliefs, preferences, and satisfaction with the prescribed treatment [8–14]. Denosumab is a human monoclonal antibody with affinity and specificity for RANK ligand, thereby inhibiting osteoclast formation, function, and survival [15]. A single subcutaneous injection of denosumab, 60 mg (Prolia®), has been shown to increase bone mineral density (BMD) and decrease bone turnover markers for at least 6 months Pevonedistat concentration [16]. In clinical trials, subcutaneous denosumab once every 6 months was well tolerated, increased BMD [17–19], and significantly reduced fracture risk [20]. Denosumab was also associated with significantly greater increases in BMD at the femoral neck, trochanter, Olaparib mouse lumbar spine, and one-third radius compared with once-weekly oral alendronate treatment [19]. The Denosumab Adherence Preference Satisfaction (DAPS) study evaluated adherence (including both compliance and persistence) to 12 months of treatment with subcutaneous denosumab, 60 mg every

6 months, and 12 months of treatment with oral alendronate, 70 mg once weekly, using a randomized, crossover design. This enabled evaluation of the primary efficacy endpoint of adherence during the first year, as reported previously [21], as well as adherence, compliance, persistence, patient beliefs, preference, satisfaction, and bother after subjects received both treatments. In addition, the crossover design provided information find more about the effect of administration sequence on adherence to denosumab and alendronate. PD-0332991 ic50 This report presents the final results from both years of the DAPS study. Methods Study design Eligible subjects were randomized in a 1:1 allocation to one of two treatment sequences—denosumab/alendronate or alendronate/denosumab—and received each treatment for 1 year. All study treatments were administered open label.

One group of subjects received oral alendronate, 70 mg once weekly, in the first year, and then crossed over to subcutaneous denosumab, 60 mg every 6 months, in the second year (given on day 1 and month 6 of the second year). The other group received the same treatments, but in reverse order. Subjects who terminated treatment before the end of the first year of study but who agreed to therapy in the second year were allowed to cross over treatment and enter the second year early. Eligibility criteria This multicenter, randomized, open-label, crossover study was conducted at 20 centers in the USA and 5 centers in Canada between October 2007 and July 2010 (Appendix). Subjects enrolled were ambulatory, postmenopausal women, aged 55 years or older, with baseline BMD T-scores between −4.0 and −2.0 at the lumbar spine, total hip, or femoral neck as measured by dual energy X-ray absorptiometry.