Cost-effectiveness Analysis of Ado-trastuzumab Emtansine (T-DM1) for the Adjuvant Treatment of Patients With Residual Invasive HER2+ Early Breast Cancer in the United States.

OBJECTIVE: Ado-trastuzumab emtansine (T-DM1) was recently approved for patients with human epidermal growth factor receptor 2 positive (HER2+) early breast cancer (eBC) with residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment. Cost-effectiveness analysis was conducted to compare T-DM1 versus trastuzumab in the United States. MATERIALS AND METHODS: A Markov cohort-based model tracked clinical and economic outcomes over a lifetime horizon from a US payer perspective. The model included 6 health states: invasive disease-free, nonmetastatic (locoregional) recurrence, remission, first-line and second-line metastatic BC and death. Model state transitions were based on statistical extrapolation of the head-to-head KATHERINE study and published sources. Dosing and treatment duration reflected prescribing information and trials. Costs (2019 US dollars) associated with pharmaceutical treatment (wholesale acquisition costs), health state specific care, adverse events, and end-of-life care were included. Health state utilities were obtained from KATHERINE and published literature. RESULTS: T-DM1 dominated trastuzumab, yielding lower lifetime costs (-$40,271), and higher life-years (2.980) and quality-adjusted life-years (2.336). Results were driven by patients receiving T-DM1 spending less time in more costly downstream health states, as these patients are less likely to experience a recurrence overall, despite having a higher likelihood of metastatic disease (distant recurrence) in the subset of patients who experience recurrence. Probabilistic sensitivity analysis indicated robust results, with 96.7% of 5000 stochastic simulations producing dominance for T-DM1. The most influential variables were related to treatment costs, off treatment utilities, and health state costs. Additional scenario analyses tested a range of model inputs and assumptions, and produced consistent results. CONCLUSION: Relative to trastuzumab, T-DM1 treatment for patients with HER2+ eBC who have residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment is likely to reduce the overall financial burden of cancer, while simultaneously improving patient outcomes.

Cost-Effectiveness of Neoadjuvant-Adjuvant Treatment Strategies for Women With ERBB2 (HER2)-Positive Breast Cancer.

Importance: The neoadjuvant treatment options for ERBB2-positive (also known as HER2-positive) breast cancer are associated with different rates of pathologic complete response (pCR). The KATHERINE trial showed that adjuvant trastuzumab emtansine (T-DM1) can reduce recurrence in patients with residual disease compared with patients treated with trastuzumab; however, T-DM1 and other ERBB2-targeted agents are costly, and understanding the costs and health consequences of various combinations of neoadjuvant followed by adjuvant treatments in the United States is needed. Objective: To examine the costs and disease outcomes associated with selection of various neoadjuvant followed by adjuvant treatment strategies for patients with ERBB2-positive breast cancer. Design, Setting, and Participants: In this economic evaluation, a decision-analytic model was developed to evaluate various neoadjuvant followed by adjuvant treatment strategies for women with ERBB2-positive breast cancer from a health care payer perspective in the United States. The model was informed by the KATHERINE trial, other clinical trials with different regimens from the KATHERINE trial, the Flatiron Health Database, McKesson Corporation data, and other evidence in the published literature. Starting trial median age for KATHERINE patients was 49 years (range, 24-79 years in T-DM1 arm and 23-80 years in trastuzumab arm). The model simulated patients receiving 5 different neoadjuvant followed by adjuvant treatment strategies. Data analyses were performed from March 2019 to August 2020. Exposure: There were 4 neoadjuvant regimens: (1) HP: trastuzumab (H) plus pertuzumab (P), (2) THP: paclitaxel (T) plus H plus P, (3) DDAC-THP: dose-dense anthracycline/cyclophosphamide (DDAC) plus THP, (4) TCHP: docetaxel (T) plus carboplatin (C) plus HP. All patients with pCR, regardless of neoadjuvant regimen, received adjuvant H. Patients with residual disease received different adjuvant therapies depending on the neoadjuvant regimen according to the 5 following strategies: (1) neoadjuvant DDAC-THP followed by adjuvant H, (2) neoadjuvant DDAC-THP followed by adjuvant T-DM1, (3) neoadjuvant THP followed by adjuvant DDAC plus T-DM1, (4) neoadjuvant HP followed by adjuvant DDAC/THP plus T-DM1, or (5) neoadjuvant TCHP followed by adjuvant T-DM1. Main Outcomes and Measures: Lifetime costs in 2020 US dollars and quality-adjusted life-years (QALYs) were estimated for each treatment strategy, and incremental cost-effectiveness ratios were estimated. A strategy was classified as dominated if it was associated with fewer QALYs at higher costs than the alternative. Results: In the base-case analysis, costs ranged from $415 833 (strategy 3) to $518 859 (strategy 4), and QALYs ranged from 9.67 (strategy 1) to 10.73 (strategy 3). Strategy 3 was associated with the highest health benefits (10.73 QALYs) and lowest costs ($415 833) and dominated all other strategies. Probabilistic analysis confirmed that this strategy had the highest probability of cost-effectiveness (>70% at willingness-to-pay thresholds of $0-200,000/QALY) and was associated with the highest net benefit. Conclusions and Relevance: These results suggest that neoadjuvant THP followed by adjuvant H for patients with pCR or followed by adjuvant DDAC plus T-DM1 for patients with residual disease was associated with the highest health benefits and lowest costs for women with ERBB2-positive breast cancer compared with other treatment strategies considered.

A cost-effectiveness analysis of trastuzumab-containing treatment sequences for HER-2 positive metastatic breast cancer patients in Taiwan.

OBJECTIVE: Treatment options for HER-2-positive metastatic breast cancer (mBC) patients have expanded markedly since trastuzumab approval in 1998. Several other regimens are now available, including pertuzumab plus trastuzumab plus docetaxel, T-DM1, capecitabine plus lapatinib, and trastuzumab plus lapatinib. This study assesses the cost-effectiveness of four treatment sequences for HER-2-positive mBC according to the Taiwanese National Health Insurance Administration (TNHIA). METHODS: Costs (U.S. Dollars) and effectiveness (quality-adjusted life years) of four treatment sequences for HER-2-positive mBC patients were examined using a Markov model over a lifetime horizon. Transition probabilities, disease progression, and probability of adverse events and survival were derived from clinical trial data. Costs and health utilities were estimated from TNHIA, Taipei Medical University Hospital, and the literature. Deterministic, probabilistic sensitivity analyses and a scenario analysis examined parameter uncertainty and accounted for drug wastage in dosage and cost calculations. RESULTS: Sequence 3 (1st line: trastuzumab plus docetaxel; 2nd line: T-DM1; 3rd line: trastuzumab plus lapatinib) was the most cost-effective sequence followed by sequence 1 (1st line: pertuzumab plus trastuzumab plus docetaxel; 2nd line: T-DM1; 3rd line: capecitabine plus lapatinib), and sequence 4 (1st line: trastuzumab plus docetaxel; 2nd line: trastuzumab plus lapatinib; 3rd line: trastuzumab plus capecitabine), respectively. The model was sensitive to costs and transition probabilities, but not particularly sensitive to the wastage assumption. CONCLUSIONS: From the perspective of the TNHIA, trastuzumab plus docetaxel as 1st line followed by T-DM1 and trastuzumab plus lapatinib as 2nd and 3rd line represents the most cost-effective strategy among the four sequences considered for treating HER-2-positive mBC patients.