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: For the pharmaco-economic evaluation, the selected comparators are Palbociclib plus Fulvestrant and Abemaciclib plus Fulvestrant for post ET setting; Everolimus plus Exemestane for post CDK4/6s plus AI utilization. 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 OS, utility values, and probabilities of adverse events were based on data from the SOLAR-1 study and literature¹. When local cost data was available, these were used. When local cost data were unavailable, UK costs were adapted to reflect 2021 Oman costs.

Results: In the base case SOLAR-1 analysis the incremental cost-effectiveness ratio (ICER) for Alpelisib plus Fulvestrant is dominant versus Palboiclib plus Fulvestrant and dominant versus Abemaciclib plus Fulvestrant. In the secondary analysis based on BYLieve the ICER for Alpelisib plus Fulvestrant is estimated to be $117,177 per QALY gained versus Everolimus plus Exemestane. Comparing this result to the proposed USA ICER threshold range, this ICER is within the range and would be termed cost-effective³.

Conclusion: Alpelisib plus Fulvestrant is dominant versus Palbociclib plus Fulvestrant and Abemaciclib plus Fulvestrant, this indicates Alpelisib is less costly and more effective than these treatments. Hence, Alpelisib plus Fulvestrant is a cost-effective strategy in HR+/HER2- advanced breast cancer patients in Oman. We can assume by reimbursing Alpelisib plus Fulvestrant this would be an effective use of healthcare resources.