国立保健医療科学院 保健医療経済評価研究センター
Center for Outcomes Research and Economic
Evaluation for Health (C2H), National Institute of
Public Health (NIPH) | URL: http://c2h.niph.go.jp

April 26th, 2022

[C2H2003] Summary of cost–effectivenessevaluation of trastuzumab deruxtecan (Enhertu)
1. Indications･ Unresectable or metastatic HER2-positive breast cancer patients who havereceived chemotherapy･ Unresectable or metastatic HER2-positive gastric cancer patients who haveprogressed after chemotherapy
2. Price of the drug
Trastuzumab deruxtecan has been reimbursed since May 2020 at JPY 168,434 (as ofApril 2022). The price is calculated using a similar efficacy comparison method, witha usefulness premium of 5%. This product is designated as an H1 cost–effectivenessevaluation item.
3. Scope of cost–effectiveness evaluation

Hereafter, the scope of evaluation agreed upon at the first session of the Expert
Committee of Cost–Effectiveness Evaluation (ECCEE) is described. This productis used for HER2-positive metastatic or gastric cancer. As the effectiveness oftrastuzumab deruxtecan for gastric cancer is not likely homogeneous depending on
the gene expression, the population was divided into two parts.

Breast cancer
Unresectable or metastatic HER2-positive patients who have
Population

received prior anti-HER2-based regimens;(a) second-line therapy(b) third- or more line therapy

1Gastric cancer
Third-line therapy for unresectable or metastatic HER2positive patients;(a) patients with HER2-positive (IHC 3+)(b) patients with HER2-positive (IHC 2+ and ISH+)
Breast cancer
Population (a)/(b): Trastuzumab and chemotherapy with theComparator

lowest price

Gastric cancer
Population (a)/(b): Nivolumab
4. Evaluation of additional benefits

Breast cancer: A systematic review found no clinical studies for population (a),while a single-arm U201 trial was found for population (b). Both the manufacturer
and academic group deduced that it is impossible to assess additional benefits inpopulation (a) because of the lack of clinical data. To analyze population (b), themanufacturer compared the U201 trial with the existing cohort studies andrandomized controlled trials (RCT) using MAIC (matched-adjusted indirectcomparison). Based on the results, the manufacturer insisted trastuzumab
deruxtecan has additional benefits to the comparator. Contrarily, the academic
group insisted that it is impossible to analyze because the results by MAIC could
be largely biased as the randomized DESTINY-Breast 02 trial is ongoing. The third
session of the ECCEE indicated that the existing data should be used for theevaluation. Moreover, they concluded that trastuzumab deruxtecan has additional

benefits to the comparator based on the results by the manufacturer.
Gastric cancer: The systematic review yielded a randomized J202 trial, which
compared

trastuzumabderuxtecan

withpaclitaxel

oririnotecan.

Themanufacturer used MAIC to compare trastuzumab deruxtecan (J202 trial) withthe existing cohort study. In contrast, the academic analysis applied indirectcomparison using the J202 trial and the results of the network meta-analysis.
The third session of the ECCEE concluded that the results of the academic group aremore appropriate. Based on the discussion, trastuzumab deruxtecan has additional

benefits for population (a) and not population (b).
5. Results of the cost–effectiveness analysis

The manufacturer estimated cost–effectiveness by the partition survival model.
2

The academic group suggested that the quality of life (QOL) score of patientswith breast cancer after third- or more line therapy is too low. In the analysis for
gastric cancer, treatment effects estimated by the academic group were used.
The ECCEE accepted the following:

Population

ICER (JPY/QALY)

Breast cancer (a) second-line

Impossible to analyze

Breast cancer (b) third- or more line

7,922,603

Gastric cancer (a) IHC 3+

12,235,903

Gastric cancer (b) IHC 2+and ISH+

Cost increase3