Cost-effectiveness of denosumab in the treatment of postmenopausal osteoporosis in Canada

Abstract

Objective:

Denosumab is a novel biologic agent approved in Canada for treatment of post-menopausal osteoporosis (PMO) in women at high risk for fracture or who have failed or are intolerant to other osteoporosis therapies. This study estimated cost-effectiveness of denosumab vs usual care from the perspective of the Ontario public payer.

Methods

A previously published PMO Markov cohort model was adapted for Canada to estimate cost-effectiveness of denosumab. The primary analysis included women with demographic characteristics similar to those from the pivotal phase III denosumab PMO trial (FREEDOM; age 72 years, femoral neck BMD T-score −2.16 SD, vertebral fracture prevalence 23.6%). Three additional scenario sub-groups were examined including women: (1) at high fracture risk, defined in FREEDOM as having at least two of three risk factors (age 70+; T-score ≤ −3.0 SD at lumbar spine, total hip, or femoral neck; prevalent vertebral fracture); (2) age 75+; and (3) intolerant or contraindicated to oral bisphosphonates (BPs). Analyses were conducted over a lifetime horizon comparing denosumab to usual care (‘no therapy’, alendronate, risedronate, or raloxifene [sub-group 3 only]). The analysis considered treatment-specific persistence and post-discontinuation residual efficacy, as well as treatment-specific adverse events. Both deterministic and probabilistic sensitivity analyses were conducted.

Results:

The multi-therapy comparisons resulted in incremental cost-effectiveness ratios for denosumab vs alendronate of $60,266 (2010 CDN$) (primary analysis) and $27,287 per quality-adjusted life year gained for scenario sub-group 1. Denosumab dominated all therapies in the remaining scenarios.

Limitations:

Key limitations include a lack of long-term, real-world, Canadian data on persistence with denosumab as well as an absence of head-to-head clinical data, leaving one to rely on meta-analyses based on trials comparing treatment to placebo.

Conclusions:

Denosumab may be cost-effective compared to oral PMO treatments for women at high risk of fractures and those who are intolerant and/or contraindicated to oral BPs.

Key words::

• Osteoporosis
• Cost-effectiveness
• Denosumab
• Fracture
• Canada
• Persistence

Transparency

Declaration of funding

This study was sponsored by Amgen Canada Inc. Both Amgen Canada Inc. and Amgen Inc. reviewed and provided comment on the draft versions of the manuscript and also approved the final version.

Declaration of financial/other relationships

DC is an employee of Amgen Inc. and has received stocks and stock options from Amgen Inc. DB and MC are employees of OptumInsight. OptumInsight was funded by Amgen Canada Inc. to adapt the model and provide editorial support for the manuscript. The authors from OptumInsight did not receive individual payments from Amgen Canada Inc. for their involvement in this study. JDA has received funding from the following companies to act as a consultant/speaker: Amgen Inc, Eli Lilly, GSK, Merck, Novartis, Pfizer, Procter & Gamble, Roche, Sanofi Aventis, and Warner Chilcott. Dr Adachi has also participated in clinical trials funded by Amgen Inc, Bristol-Myers Squibb, Eli Lilly, Merck, Novartis, Pfizer, Procter & Gamble, Sanofi Aventis, Roche, and Warner Chilcott. RG received funding from Amgen Canada Inc. to participate as a member of the Canadian Denosumab Advisory Board which helped guide the adaptation of the international model for Canada. GI has no relationships or conflicts to declare.