Introduction: In Brazil, it is estimated that OC(ovarian cancer) impacts 7/100,000 habitants every year. Until recently, platinum-based therapies were considered standards of care and few innovations could significantly reduce disease progression or survival status(PFS). PARPi(Poly ADP-ribose polymerase inhibitor), such as olaparib, has shown to improve PFS by 51% compared to placebo in first-line maintenance scenario. This result was significantly better in homologous-recombination deficiency(HRD+). New oncology drugs require significant resource allocation, so we assessed which parameters have highest impact on cost-effectiveness analysis(CEA) of olaparib as maintenance therapy for women with HRD+OC, in the Brazilian private health care system.

Methods: 4-state Partitioned Survival Decision Analytic model was used to assess maintenance strategies for patients with HRD+ status OC: olaparib-bevacizumab(OLA-BEVA) versus bevacizumab(BEVA). Clinical parameters for modelling were retrieved from PAOLA-1 trial and comprised: PFS, overall survival, adverse events and treatment discontinuation. Costs considered in the model included: drugs, adverse events, health care resource use and subsequent therapy and others. Parameters with highest impact on CEA were determined by one-way sensitivity analysis(OWSA) and probabilistic sensitivity analysis(PSA). 5% discount was applied according to local guidelines. Cost-effectiveness threshold was set at 3xgross domestic product (GDP)/capita (R$120,000).

Results: OLA-BEVA was the strategy with highest QALY (quality-adjusted life years), in comparison to BEVA (6.12vs4.33) and with incremental costs (R$129,483). The incremental cost-effectiveness ratio(ICER) was R$72,442/QALY, which can be considered cost-effective when the threshold is R$120,000/QALY. According to OWSA, the clinical data and costs with highest sensitivity were: mortality, first and second disease progression costs. Adverse events were likely to affect less the final ICER. PSA suggested that base case results were robust.

Conclusion: For women with HRD+OC, OLA-BEVA was considered a cost-effective treatment. Disease progression and survival were variables with highest impact in the model, suggesting that choosing treatments with best progression free survival results might promote better resource allocation in Brazil.