FREEDOM Cost, Cost-Effectiveness, and Health-Economic Implications

At a glance

| Parameter | Detail | |---|---| | Trial | FREEDOM | | N | 7,868 postmenopausal women | | Intervention | Denosumab 60 mg SC every 6 months | | Comparator | Placebo (both arms received calcium + vitamin D) | | Duration | 36 months | | Primary endpoint | New vertebral fractures at 36 months | | Key result | 68% relative risk reduction in vertebral fractures (RR 0.32, 95% CI 0.26-0.41) | | Registry | NCT00089791 |

Why FREEDOM Became the Anchor for Economic Models

The FREEDOM trial randomized 7,868 women aged 60 to 90 with T-scores between -2.5 and -4.0 at the lumbar spine or total hip. Over three years, denosumab reduced vertebral fractures by 68%, hip fractures by 40%, and nonvertebral fractures by 20%. Those effect sizes were large enough, and the population well-characterized enough, that health economists immediately began building cost-effectiveness models around the dataset.

Several features of the trial made it particularly useful for modeling. The placebo arm provided clean baseline fracture rates. The FREEDOM extension study eventually delivered up to 10 years of continuous-exposure safety and efficacy data. And the subcutaneous, twice-yearly dosing created a predictable cost structure that simplified budget-impact calculations for payers.

The Core Cost-Effectiveness Models

The Amgen-Sponsored Markov Model (2010)

The first formal cost-effectiveness analysis appeared shortly after the primary FREEDOM publication. Using a Markov state-transition model, Hiligsmann and colleagues projected lifetime fracture outcomes, costs, and quality-adjusted life years (QALYs) for denosumab versus no treatment in postmenopausal women at varying fracture risk levels.

| Subgroup | ICER (cost per QALY) | Below $50K threshold? | |---|---|---| | Age 60, T-score -2.5 | ~$55,000-$65,000 | Borderline | | Age 70, T-score -2.5 | ~$28,000-$40,000 | Yes | | Age 70, prior fracture | ~$15,000-$25,000 | Yes | | Age 80, prior fracture | <$20,000 | Yes |

The pattern is consistent: denosumab becomes more cost-effective as baseline fracture risk increases. For a 70-year-old woman with a prior vertebral fracture, the incremental cost-effectiveness ratio fell comfortably below accepted thresholds in most sensitivity analyses.

European and Multi-Country Analyses

Separate models adapted these findings to UK, Swedish, Belgian, and Canadian health systems. Results varied by local drug pricing, fracture-related hospitalization costs, and willingness-to-pay norms. In the UK NICE assessment, denosumab was recommended for postmenopausal women who could not tolerate oral bisphosphonates or for whom they were contraindicated, a narrower population than the full FREEDOM cohort. The Belgian analysis by Hiligsmann et al. (2013) found an ICER of approximately EUR 15,600 per QALY for women aged 70 and older with a T-score of -2.5 or below. Swedish modeling consistently placed the cost per QALY between $20,000 and $35,000 for high-risk patients.

Denosumab vs. Oral Bisphosphonates

Most early models compared denosumab to placebo or "no treatment" because that was the FREEDOM design. The more clinically relevant question, how denosumab compares to generic alendronate at roughly $0.50 per day, produced less favorable ICERs. A 2017 systematic review of osteoporosis economic evaluations found that denosumab was cost-effective versus no treatment in 85% of published analyses but cost-effective versus generic oral bisphosphonates in only about 40% of models.

This gap matters clinically. The AACE 2020 guidelines and the Endocrine Society guidelines both position denosumab as an appropriate first-line option, but many insurers still require a bisphosphonate trial first, precisely because the head-to-head economic case is weaker.

List Price vs. Net Price vs. What Patients Actually Pay

The wholesale acquisition cost (WAC) for Prolia in the U.S. has risen since its 2010 launch. As of early 2026, the list price sits near $1,800 per injection, or roughly $3,600 per year. After rebates negotiated by pharmacy benefit managers, the effective net price for commercial insurers typically falls to $2,400-$2,800 annually.

For Medicare Part B beneficiaries, Prolia is covered as a physician-administered injectable. Patient out-of-pocket responsibility under Part B is typically 20% of the Medicare-allowed amount after the deductible, translating to roughly $300-$400 per year. That is a meaningful expense, but far below the list-price sticker shock.

The Biosimilar Horizon

The FDA-approved denosumab biosimilar, Wyost (denosumab-bbdz), received approval in 2025. Biosimilar competition is expected to compress net pricing by 20% to 40% within three to five years of launch. If annual treatment costs drop to $1,500-$2,000, every published cost-effectiveness model improves substantially, potentially pushing ICERs below $20,000 per QALY even versus generic bisphosphonates.

The Discontinuation Problem: An Undermodeled Cost

Most cost-effectiveness models assume continuous treatment for a fixed duration (typically 5 years in the base case, sometimes 10). They underweight a critical real-world cost: the rebound vertebral fracture risk after denosumab discontinuation.

Patients who stop denosumab without transitioning to a bisphosphonate experience rapid bone mineral density loss and, in some cases, multiple vertebral fractures within 12 to 18 months. This phenomenon, absent from the original FREEDOM data because participants continued in the extension, was documented in post-marketing observational studies and is now well-recognized.

From a health-economic perspective, discontinuation-related fractures add downstream costs that are rarely captured in the models. A patient who takes denosumab for three years, stops without a bridging bisphosphonate, and sustains two vertebral compression fractures may incur $30,000-$50,000 in acute care costs plus ongoing pain management. That scenario erodes much of the QALY gain the initial treatment provided.

Any honest cost-effectiveness estimate must account for either indefinite treatment or the cost of a structured transition protocol. The 2020 position statement from the European Calcified Tissue Society recommends at least one to two years of oral or IV bisphosphonate following denosumab cessation, adding $200-$1,200 per year in transition costs.

Payer Coverage Patterns

U.S. Commercial Insurers

Most large commercial plans cover Prolia with prior authorization. Common requirements include documented T-score at or below -2.5, intolerance or contraindication to oral bisphosphonates, or a history of fragility fracture. Step therapy (requiring a bisphosphonate trial first) remains standard at roughly 60% of plans surveyed in formulary analyses.

Medicare

Part B coverage for Prolia is relatively straightforward because it is physician-administered. The Prolia prescribing information carries an FDA-approved indication for postmenopausal women with osteoporosis at high risk for fracture, which aligns with the Medicare coverage determination.

International Systems

In Canada, provincial formularies generally restrict denosumab to second-line use after bisphosphonate failure. Australia's Pharmaceutical Benefits Scheme takes a similar approach. The UK's NICE technology appraisal (TA204, updated TA791) limits first-line access to patients meeting specific FRAX-based fracture risk thresholds.

The Individual Patient Value Calculation

For a patient deciding whether to start denosumab, the abstract ICER is less useful than a concrete personal calculation.

Factors that push toward higher value:

• Age over 65 with a prior fragility fracture
• T-score at or below -3.0
• Inability to take oral bisphosphonates (esophageal stricture, GI intolerance, cognitive impairment affecting weekly dosing compliance)
• Preference for a twice-yearly injection over daily or weekly pills

Factors that push toward lower value:

• Treatment-naive with a T-score between -2.5 and -2.7 and no fracture history
• Good tolerance of generic alendronate
• Uncertain commitment to long-term treatment (given the discontinuation risk)
• Limited insurance coverage, making out-of-pocket costs exceed $1,500 per year

The FREEDOM trial's number needed to treat (NNT) for vertebral fractures over three years was approximately 10. For hip fractures, the NNT was approximately 200. A patient with high vertebral fracture risk gets far more expected benefit per dollar than one whose primary concern is hip fracture.

Limitations of the Existing Economic Literature

Several recurring weaknesses appear across published analyses. First, most models were industry-funded, which does not invalidate them but does create systematic pressure toward favorable assumptions (longer time horizons, lower discount rates, higher fracture disutilities). Second, few models incorporated real-world adherence data. The FREEDOM protocol achieved >95% injection adherence because research coordinators administered every dose, a level of compliance that community practice does not replicate. Third, indirect costs (lost productivity, caregiver burden) are included inconsistently. When they are included, the ICER improves because fractures carry substantial indirect costs. When excluded, the model captures only direct medical spending.

Frequently asked questions

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References

1. Cummings SR, San Martin J, McClung MR, et al. Denosumab for prevention of fractures in postmenopausal women with osteoporosis. N Engl J Med. 2009;361(8):756-765. PubMed
2. Hiligsmann M, Reginster JY. Cost-effectiveness of denosumab compared with oral bisphosphonates in the treatment of postmenopausal osteoporotic women in Belgium. Pharmacoeconomics. 2011;29(10):895-911. PubMed
3. Bone HG, Wagman RB, Brandi ML, et al. 10 years of denosumab treatment in postmenopausal women with osteoporosis: results from the phase 3 randomised FREEDOM trial and open-label extension. Lancet Diabetes Endocrinol. 2017;5(7):513-523. PubMed
4. Prolia (denosumab) prescribing information. Amgen Inc. Revised 2020. FDA Label
5. Camacho PM, Petak SM, Binkley N, et al. American Association of Clinical Endocrinologists/American College of Endocrinology clinical practice guidelines for the diagnosis and treatment of postmenopausal osteoporosis, 2020 update. Endocr Pract. 2020;26(Suppl 1):1-46. PubMed
6. Tsourdi E, Langdahl B, Cohen-Solal M, et al. Discontinuation of denosumab therapy for osteoporosis: a systematic review and position statement by ECTS. Bone. 2017;105:11-17. PubMed