Background: In the PAOLA-1 trial, olaparib plus bevacizumab demonstrated significant clinical benefit following partial or complete response to platinum-based chemotherapy in homologous recombination deficiency (HRD)-positive ovarian cancer. Our study evaluated the cost effectiveness of olaparib plus bevacizumab compared with bevacizumab alone as a maintenance treatment for women in this population.
Methods: Our model was a cohort-level partitioned survival model with a lifetime horizon from a US healthcare system perspective. Its four health states were progression-free, post first progression, post second progression, and death, modeled using time to first progression (PFS1), second progression (PFS2), and overall survival (OS) from PAOLA-1. We modeled PFS1 through mixture survival modeling, and PFS2 and OS by fitting standard parametric models. Time-on-treatment was sourced directly from PAOLA-1, with treatment capped at 24 months for olaparib and 15 months for bevacizumab. Costs included drug acquisition and administration, adverse events, disease management, biomarker testing, and subsequent treatments. Deterministic and probabilistic sensitivity analyses tested the results.
Results: Compared with bevacizumab alone, olaparib plus bevacizumab increased quality-adjusted life-years (QALYs; +2.89) and life-years (LYs; +3.43) at an incremental cost of $164,209, leading to an incremental cost-effectiveness ratio of $56,863 per QALY. Olaparib plus bevacizumab had a 97.0% probability of being cost effective compared with bevacizumab alone at a willingness-to-pay threshold of $100,000 per QALY.
Conclusion: The addition of olaparib to bevacizumab led to clinically significant increases in progression-free survival, resulting in substantial predicted LYs and QALYs gained, while being cost effective in the maintenance treatment of advanced ovarian cancer with HRD in the US.
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