Introduction: The aim of this current study is to estimate the cost-effectiveness of Alpelisib plus Fulvestrant in HR+/HER2- advanced Breast Cancer patients with a PIK3CA mutation.

Methods: A partition survival model (PSM) was used to calculate the cost effectiveness over a 40-year time horizon. The PSM approach includes three health states for Progression Free Survival (PFS), Post-Progression Survival (PPS) and dead. Membership in the three states over time is determined by efficacy parameters in the form of survival curves. Probabilities of PFS and Overall Survival (OS), utility values, and probabilities of adverse events were based on data from the SOLAR-1 study and literature (1). Where local cost data was available these were used. When local cost data were unavailable UK costs were adapted to reflect 2021 Qatar costs. The model was estimated and analyzed for the PIK3CA mutant subgroup in SOLAR-1 (1).

Results: In the base case population based on the SOLAR-1 analysis the incremental cost-effectiveness ratio (ICER) for Alpelisib plus Fulvestrant is estimated to be $45,490 per quality-adjusted life year (QALY) versus Palboiclib plus Fulvestrant and $11,876 versus Abemaciclib plus Fulvestrant. In the secondary analysis, based on the BYLieve analysis the ICER for Alpelisib plus Fulvestrant is estimated to be $147,657 per QALY gained versus Everolimus plus Exemestane.

Conclusion: As there is no explicit Cost effectiveness threshold in Qatar it was assumed values within one gross domestic product per capita (GDPPC) and three times GDPPC are considered cost effective (3). The range would be $62,088/QALY to $186,264/QALY. Alpelisib plus Fulvestrant is a cost effective strategy in HR+/HER2- advanced breast cancer patients in Qatar. We can assume by reimbursing Alpelisib plus Fulvestrant this would be an effective use of healthcare resources.