Additional Data
Patient-reported outcomes of health-related quality of life in DESTINY-Breast031
PROs of HRQoL were prespecified secondary endpoints in DESTINY-Breast03 and were assessed throughout the study

Primary endpoint
- PFS (BICR)
Key secondary endpoint
- OS
Secondary endpoints
- ORR (BICR and investigator)
- DOR (BICR)
- PFS (investigator)
- Safety
- HEOR outcomes (PROs and hospitalization rates)
PRO endpoint assessment schedulee:
- Cycle 1
- Cycle 2
- Cycle 3
- Every 2
cycles
(cycle 5, 7, 9,
etc) - Every 2 cycles
(cycle 5, 7, 9, etc) - EOT
- 40-day
follow-up - 3-month
follow-up
Reprinted from Annals of Oncology, Vol. 34(7), Curigliano G, Dunton K, Rosenlund M, et al., Patient-reported outcomes and hospitalization data in patients with HER2-positive metastatic breast cancer receiving trastuzumab deruxtecan or trastuzumab emtansine in the phase III DESTINY-Breast03 study, Pages No. 569-577, Copyright 2023, with permission from Elsevier.
aHER2 IHC 3+ or IHC 2+/ISH+ based on central confirmation.
bProgression during or <6 months after completing adjuvant therapy involving trastuzumab and a taxane.
cFour patients were randomly assigned but not treated.
dTwo patients were randomly assigned but not treated.
e1 cycle, 21 days; ENHERTU or T-DM1 administered on day 1 of each cycle; questionnaires completed before treatment on day 1 of cycles indicated.
HRQoL for patients was assessed across several measurements
Primary and secondary PRO assessment instruments and variables of interest
Oncology-specific Quality of Life Questionnaire Core 30
- Global health status (GHS)/quality of life (QoL)f
- Physical functioningg
- Emotional functioningg
- Social functioningg
- Pain symptomsg
Breast cancer–specific instrument
- Arm symptomsg
- Breast symptomsg
EuroQol 5-dimension 5-level
questionnaire visual
analogue scale
- Visual analogue scale (VAS)g
- Analyses included change from baseline, time to definitive deterioration, and hospitalization-related endpoints
- Most patients in both treatment groups completed the QoL questionnaires as prescribed in the trial
- >97% compliance at baseline
- >82% compliance from cycles 3-27
- >90% compliance at the follow-up
Patients who had discontinued the trial were not included in further PRO assessments.
fPrimary PRO variable of interest.
gSecondary PRO variable of interest.
HRQoL was assessed using 3 PRO measures in DESTINY-Breast031
Median time to definitive deterioration in patient-reported QoL measures in DESTINY-Breast03

- Time to definitive deterioration was defined as the number of days between the date of randomization and the date of the assessment at which the definitive deterioration event (a prespecified, ≥10-point change from baseline of the specific score in the direction of deterioration [positive for symptom scales, negative for all others], and deterioration on two or more consecutive visits or at last visit), is first seen
Reprinted from Annals of Oncology, Vol. 34(7), Curigliano G, Dunton K, Rosenlund M, et al., Patient-reported outcomes and hospitalization data in patients with HER2-positive metastatic breast cancer receiving trastuzumab deruxtecan or trastuzumab emtansine in the phase III DESTINY-Breast03 study, Pages No. 569-577, Copyright 2023, with permission from Elsevier.
PRO measures are reported such that a high GHS/QoL or VAS score represents a high QoL, a high score on functional scales represents a high level of functioning, and a high score on symptom scales represents a high level of symptomatology. Time to definitive deterioration was defined as the number of days between the date of randomization and the date of the assessment at which the definitive deterioration event is first observed (ie, a change exceeding +10 points for symptom scales, or a change exceeding –10 points for GHS, VAS, and functional scales, with deterioration on two or more consecutive visits or at last visit). P values are not adjusted for multiple testing.
hPrimary PRO variable of interest.
iSecondary PRO variable of interest.
EORTC QLQ-C30 GHS was assessed over time in DESTINY-Breast031
EORTC QLQ-C30 GHS change from baseline over time in patients treated with ENHERTU and T-DM1

- Scores range from 0 to 100; the investigators considered a higher score to represent higher (“better”) GHS/overall QoL
Limitations: The EORTC QLQ-C30 is not all-inclusive and does not include adequate assessment of additional expected treatment-related symptoms or overall side effect bother from the patient perspective. The results should be interpreted with caution due to the open-label design of the study and because time to definitive deterioration may be confounded by events not related to disease/treatment
Reprinted from Annals of Oncology, Vol. 34(7), Curigliano G, Dunton K, Rosenlund M, et al., Patient-reported outcomes and hospitalization data in patients with HER2-positive metastatic breast cancer receiving trastuzumab deruxtecan or trastuzumab emtansine in the phase III DESTINY-Breast03 study, Pages No. 569-577, Copyright 2023, with permission from Elsevier.
BICR, blinded independent central review; CI, confidence interval; DOR, duration of response; EORTC, European Organization for Research and Treatment of Cancer; EOT, end of treatment; EQ-5D-5L, EuroQoL 5-dimension, 5-level questionnaire; GHS, global health status; HEOR, health economics and outcomes research; HER2, human epidermal growth factor receptor 2; HR, hazard ratio; HRQoL, health-related quality of life; IHC, immunohistochemistry; ISH, in situ hybridization; NE, not evaluable; ORR, objective response rate; OS, overall survival; PRO, patient-reported outcome; Q3W, every 3 weeks; QLQ-BR45, Quality of Life Breast Cancer questionnaire; QLQ-C30, Quality of Life Questionnaire Core 30; QoL, quality of life; TDD, time to definitive deterioration; T-DM1, ado-trastuzumab emtansine; VAS, visual analogue scale.