COST-EFFECTIVENESS OF INAVOLISIB IN THE TREATMENT OF PIK3A-MUTATED, HR+/HER2-ABC LOCALLY ADVANCED OR METASTATIC BREAST CANCER IN THE US
Author(s)
Ogini Faith, PharmD1, Rakchhya Uprety, PharmD2, La'marcus Wingate, PhD3;
1Howard University College of Pharmacy, Northwest DC 20059, DC, USA, 2Howard University College of Pharmacy, Hyattsville, MD, USA, 3Howard University College of Pharmacy, Washington, DC, USA
1Howard University College of Pharmacy, Northwest DC 20059, DC, USA, 2Howard University College of Pharmacy, Hyattsville, MD, USA, 3Howard University College of Pharmacy, Washington, DC, USA
OBJECTIVES: Inavolisib has demonstrated a significant improvement in progression-free survival in the management of PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer (HR+/HER2-ABC). However, its high cost may limit adoption. Hence, this study evaluated the cost-effectiveness of Inavolisib plus palbociclib-fulvestrant compared with placebo plus palbociclib-fulvestrant from a US payer perspective.
METHODS: A cost-effectiveness analysis was conducted using a parametric survival model. Safety and efficacy data were obtained from the INAVO120 trial. This study employed a 10-year time horizon with 28-day cycles. Utility and cost data were sourced from peer-reviewed literature. Inavolisib cost was based on the 2025 wholesale acquisition cost (WAC). Costs were expressed in 2025 USD, and both costs and QALYs were discounted at 3% annually. The incremental cost-effectiveness ratio (ICER) was calculated to compare the two treatment strategies, using willingness-to-pay (WTP) thresholds of $150,000/QALY and $300,000/QALY. Parameter uncertainty was evaluated through one-way and two-way sensitivity analyses.
RESULTS: In the base-case analysis, Inavolisib + palbociclib-fulvestrant was more effective (2.2 vs 1.8) at an incremental cost of $585,804.4 compared with the placebo + palbociclib-fulvestrant group. The resulting ICER was $1.45 million/QALY, exceeding commonly accepted US WTP thresholds. One-way sensitivity analysis varying drug cost showed that Inavolisib remained above both $150,000/QALY and $300,000/QALY thresholds across all plausible price values. In the two-way sensitivity analysis, varying tablet cost and incremental QALYs, the combination was cost-effective in 1.97% of evaluated parameter combinations at a WTP of $300,000/QALY.
CONCLUSIONS: At its current 2025 WAC ($751 per 9-mg tablet), Inavolisib was not cost-effective for patients with PIK3A-mutated, HR+/HER2-ABC. Further price negotiations are required to achieve favorable economic value within acceptable US WTP thresholds.
METHODS: A cost-effectiveness analysis was conducted using a parametric survival model. Safety and efficacy data were obtained from the INAVO120 trial. This study employed a 10-year time horizon with 28-day cycles. Utility and cost data were sourced from peer-reviewed literature. Inavolisib cost was based on the 2025 wholesale acquisition cost (WAC). Costs were expressed in 2025 USD, and both costs and QALYs were discounted at 3% annually. The incremental cost-effectiveness ratio (ICER) was calculated to compare the two treatment strategies, using willingness-to-pay (WTP) thresholds of $150,000/QALY and $300,000/QALY. Parameter uncertainty was evaluated through one-way and two-way sensitivity analyses.
RESULTS: In the base-case analysis, Inavolisib + palbociclib-fulvestrant was more effective (2.2 vs 1.8) at an incremental cost of $585,804.4 compared with the placebo + palbociclib-fulvestrant group. The resulting ICER was $1.45 million/QALY, exceeding commonly accepted US WTP thresholds. One-way sensitivity analysis varying drug cost showed that Inavolisib remained above both $150,000/QALY and $300,000/QALY thresholds across all plausible price values. In the two-way sensitivity analysis, varying tablet cost and incremental QALYs, the combination was cost-effective in 1.97% of evaluated parameter combinations at a WTP of $300,000/QALY.
CONCLUSIONS: At its current 2025 WAC ($751 per 9-mg tablet), Inavolisib was not cost-effective for patients with PIK3A-mutated, HR+/HER2-ABC. Further price negotiations are required to achieve favorable economic value within acceptable US WTP thresholds.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EE371
Topic
Economic Evaluation
Topic Subcategory
Thresholds & Opportunity Cost, Trial-Based Economic Evaluation
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, SDC: Oncology