OBJECTIVES: Breast cancer, with its high incidence among women (45,6/100.000) is a major public health problem in Turkey. Majority of breast cancers cases (74%) are positive for estrogen and progesterone (HR+) and negative for human epidermal growth factor – 2 (HER2-). PIK3CA mutations occur in 40% of HR+/HER2- breast cancers. The objective of this study is to assess the cost-effectiveness of alpelisib in combination with fulvestrant for the treatment of post-menopausal women with PIK3CA mutant HR+/HER2- advanced breast cancer after prior treatment with an aromatase inhibitor in Turkey.

METHODS: The study was designed from the payer’s perspective (SGK). A Markov model with three stages (progression free survival, post progression survival and death) was developed. Comparators were ribociclib+fulvestrant, palbociclib+fulvestrant, fulvestrant, everolimus+exemestane and chemotherapy. Clinical effectiveness data for alpelib+fulvestrant vs fulvestrant were obtained from the SOLAR-1 clinical trial. Indirect comparisons were made for other comparators. 3% discount rate was used for both life years and costs. The model employed a 40-year time horizon and 28-day cycle length. Only direct costs were included in the analysis and cost of treatment drugs, cost of adverse events, cost of monitoring and cost of terminal care were included. Expert views were used in the absence of published cost data. ICER was calculated as the incremental cost per incremental life years (LY) as per the guidelines of the SGK.

RESULTS: Alpelisib+fulvestrant dominated all comparator treatments except fulvestrant alone. And cost-effective compared to mono fulvestrant. The ICER (cost/LY) for life years was 176,646 TL in this case. This was lower than three times the GDP per capita (257,056 TL) for 2021. Both deterministic and probabilistic sensitivity analyses have confirmed the robustness of the results.

CONCLUSIONS: Alpelisib+fulvestrant treatment in post-menapousal women with PIK3CA mutant HR+/HER2- advanced breast cancer after prior treatment with an aromatase inhibitor is a cost-effective option in Turkey.