Persistence at 12 months with denosumab in postmenopausal women with osteoporosis: interim results from a prospective observational study

Abstract

Summary

To determine persistence with subcutaneous denosumab every 6 months in women being treated for osteoporosis, we conducted a single-arm prospective, observational study in the United States and Canada. Among 935 patients enrolled, 12-month persistence was 82 %, with 66 patients (7 %) reporting serious adverse events and 19 patients (2 %) reporting fractures.

Introduction

Increased persistence with osteoporosis therapy is associated with reduced fracture risk. Denosumab reduced fracture risk in clinical trials; persistence in community settings is undetermined. This study evaluates persistence with denosumab in community practice in the United States (US) and Canada.

Methods

In a 24-month multicenter, prospective, single-arm, observational study, women being treated for osteoporosis were enrolled ≤4 weeks after the first subcutaneous injection of denosumab. For this 12-month prespecified interim analysis, endpoints include persistence (one injection at study entry and another within 6 months + 8 weeks), attributes associated with persistence (univariate analysis), and serious adverse events (SAEs).

Results

Among 935 patients (mean age 71 years), mean baseline T-scores were −2.18 (femoral neck) and −2.00 (lumbar spine); 50 % of patients had experienced osteoporotic fracture(s). At 12 months, 82 % of patients were persistent with denosumab. Baseline factors significantly ( p < 0.05) associated with higher persistence included use of osteoporosis medications >5 years previously, lumbar spine T-score > −2.5, and treatment by female physicians (US). Lower persistence was associated ( p < 0.05) with psychiatric diagnoses including depression, southern US residence, being divorced, separated, or widowed (US), and prior hip fracture (Canada). SAEs were reported in 66 patients (7 %); no SAEs of osteonecrosis of the jaw, atypical femoral fracture, fracture healing complications, hypocalcemia, eczema, or hypersensitivity were reported. Nineteen patients (2 %) reported osteoporotic fractures.

Conclusions

The 12-month persistence observed in this single-arm open-label study of US and Canadian community practice extends the evidence regarding denosumab’s potential role in reducing fracture risk in postmenopausal women with osteoporosis.

Electronic supplementary material

The online version of this article (doi:10.1007/s00198-014-2871-6) contains supplementary material, which is available to authorized users.