PMS26 COST-EFFECTIVENESS OF SEQUENTIAL TREATMENT WITH ABALOPARATIDE FOLLOWED BY ALENDRONATE VS ALENDRONATE MONOTHERAPY FOR THE PREVENTION OF FRACTURES IN POSTMENOPAUSAL US WOMEN AT INCREASED RISK OF FRACTURE

Abstract

Emerging evidence supports sequential therapy with osteoanabolic followed by antiresorptive in patients at high-risk of fragility fractures. Further cost-effectiveness evaluation of sequential abaloparatide (ABL) followed by alendronate (ALN) vs ALN monotherapy is needed to inform prescribers about the economic value of anabolic first for those at high risk of fracture. This study aims to assess the cost-effectiveness of sequential ABL followed by ALN (ABL/ALN) vs ALN monotherapy for postmenopausal osteoporosis, from the US payer perspective. A Markov microsimulation model was developed to estimate the cost-effectiveness of sequential ABL/ALN vs ALN with a lifetime horizon from the US payer perspective. Patients were assumed to receive 18 months ABL followed by 5 years ALN. The effects of ABL on fracture risk were derived from the ACTIVExtend trial and were assumed to be maintained during subsequent ALN treatment, consistent with ACTIVExtend. Evaluation was completed for high-risk patients 50-80 years old with a BMD T-score ≤-3.5 or BMD T-score between -2.5 and -3.5 and a history of ≥1 osteoporotic fracture. Sensitivity analyses were performed to test the robustness of the model results. In simulated populations, sequential ABL/ALN was cost-effective (threshold of $150,000/QALYs) vs generic ALN monotherapy, in women ≥60 years with a BMD T-score ≤-3.5 without a history of prior fracture and in women with BMD T-score between -2.5 and -3.5 and history of osteoporotic fracture. In patients aged 70 years with BMD T-score ≤-3.5, sequential ABL/ALN reduced the expected number of fractures per patient by 0.340 and increased lifetime QALY gained by 0.163 over a patient’s lifetime. Probabilistic sensitivity analyses suggested ABL/ALN was cost-effective in 65.5%, 96% and 92.5% of simulations at the ages of 60, 70 and 80 years, respectively. Sequential ABL/ALN therapy is cost-effective vs ALN monotherapy for US postmenopausal women at increased risk of fractures.