COST-EFFECTIVENESS AND UNCERTAINTY ANALYSIS OF ADJUVANT TRASTUZUMAB DERUXTECAN VERSUS T-DM1 IN HER2-POSITIVE EARLY BREAST CANCER: AN SSMC TERTIARY ONCOLOGY CENTER, UAE HTA PATHWAY MODEL
Author(s)
Ammar Abdaljalil, BSc Pharm BCOP PgDip HTA1, Aref Chehal, MD2, Aydah Alawadhi, MD2, Dalia Mahmoud Elshourbagy, MD2, Deepthi Vilasini Silymon, MD2, Aisha Mohamed Al Salami, MD2.
1Pharmacy, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates, 2Oncology/Hematology, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates.
1Pharmacy, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates, 2Oncology/Hematology, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates.
OBJECTIVES: To evaluate the cost-effectiveness and decision uncertainty of adjuvant trastuzumab deruxtecan (T-DXd) versus trastuzumab emtansine (T-DM1) for residual invasive HER2-positive early breast cancer after neoadjuvant therapy at SSMC, UAE, across HEOR, clinical, pharmacy, policy audiences.
METHODS: A five-state Markov model (invasive disease-free survival, recurrence, locoregional salvage, metastatic treatment, death; 20-year horizon, 3.5% discounting, half-cycle correction) compared T-DXd x14 with T-DM1 x14 after neoadjuvant TCHP. DESTINY-Breast05 anchored the residual-disease comparison; HER2CLIMB informed the metastatic module. Survival used reconstructed individual-patient data; iDFS was an intermediate driver, not a validated overall-survival surrogate. Independent and Cholesky-correlated PSA (10,000 iterations), OWSA (tornado), CEAC, NMB/INB, and EVPI were reported by static/dynamic willingness-to-pay threshold (AED/QALY).
RESULTS: The deterministic ICER was AED 348,225/QALY (~ US Int$ 157,127, PPP; incremental cost AED 208,744 ~ US Int$ 94,190) for 0.5995 QALYs and 0.6839 LYs per patient (LYs not utility-weighted); per 1,000 patients, T-DXd yielded 84.7 fewer recurrences, 599.5 QALYs, and 683.9 LYs. The probabilistic ICER was AED 403,193 (independent) and AED 419,753 (Cholesky), modestly higher (interpretation unchanged), conditional on the T-DM1 survival-distribution choice. Incremental NMB was negative at static (AED 150,000) and dynamic CET (AED 186,804) thresholds, turning positive at AED 500,000 (INB +50,353). The probability of cost-effectiveness rose from 0.24 to 0.57 (AED 500,000) and 0.64 (AED 750,000); EVPI was AED 38,244/patient at AED 186,804. On OWSA, the ICER was most sensitive to T-DXd cost (+/-30%; swing AED 513,682) and iDFS recurrence hazard (+/-10%; swing AED 444,550), remaining above AED 300,000/QALY except under deep T-DXd price cuts.
CONCLUSIONS: T-DXd delivers meaningful recurrence and QALY gains, but at UAE static and dynamic thresholds WTP its ICER exceeds value benchmarks with material uncertainty. For policymakers, this supports threshold-conditioned, managed-entry options (price negotiation, outcomes-based agreements, VOI evidence) - not binary accept/reject. It informs, not replaces, reimbursement decisions, which require affordability, evidence certainty, and local-data confidence.
METHODS: A five-state Markov model (invasive disease-free survival, recurrence, locoregional salvage, metastatic treatment, death; 20-year horizon, 3.5% discounting, half-cycle correction) compared T-DXd x14 with T-DM1 x14 after neoadjuvant TCHP. DESTINY-Breast05 anchored the residual-disease comparison; HER2CLIMB informed the metastatic module. Survival used reconstructed individual-patient data; iDFS was an intermediate driver, not a validated overall-survival surrogate. Independent and Cholesky-correlated PSA (10,000 iterations), OWSA (tornado), CEAC, NMB/INB, and EVPI were reported by static/dynamic willingness-to-pay threshold (AED/QALY).
RESULTS: The deterministic ICER was AED 348,225/QALY (~ US Int$ 157,127, PPP; incremental cost AED 208,744 ~ US Int$ 94,190) for 0.5995 QALYs and 0.6839 LYs per patient (LYs not utility-weighted); per 1,000 patients, T-DXd yielded 84.7 fewer recurrences, 599.5 QALYs, and 683.9 LYs. The probabilistic ICER was AED 403,193 (independent) and AED 419,753 (Cholesky), modestly higher (interpretation unchanged), conditional on the T-DM1 survival-distribution choice. Incremental NMB was negative at static (AED 150,000) and dynamic CET (AED 186,804) thresholds, turning positive at AED 500,000 (INB +50,353). The probability of cost-effectiveness rose from 0.24 to 0.57 (AED 500,000) and 0.64 (AED 750,000); EVPI was AED 38,244/patient at AED 186,804. On OWSA, the ICER was most sensitive to T-DXd cost (+/-30%; swing AED 513,682) and iDFS recurrence hazard (+/-10%; swing AED 444,550), remaining above AED 300,000/QALY except under deep T-DXd price cuts.
CONCLUSIONS: T-DXd delivers meaningful recurrence and QALY gains, but at UAE static and dynamic thresholds WTP its ICER exceeds value benchmarks with material uncertainty. For policymakers, this supports threshold-conditioned, managed-entry options (price negotiation, outcomes-based agreements, VOI evidence) - not binary accept/reject. It informs, not replaces, reimbursement decisions, which require affordability, evidence certainty, and local-data confidence.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
HTA257
Topic
Clinical Outcomes, Economic Evaluation, Health Technology Assessment
Disease
Oncology