DESTINY-Breast03 Phase 3 Study Results
DESTINY-Breast03 Study Design
Patients (N = 524)
Unresectable or metastatic HER2-
positivea breast cancer that has
R
1:1
been previously treated with
trastuzumab and a taxaneb
Stratification factors
•
Hormone receptor status
Prior treatment with pertuzumab
.
History of visceral disease
PRO endpoint assessment schedulee
Cycle 1
Cycle 2 Cycle 3
Every 2 cycles (cycle 5, 7, 9, etc)
DESTINY-Breast03
10
Daiichi-Sankyo
T-DXd
5.4 mg/kg Q3W
(n = 261)c
(open-label)
T-DM1
3.6 mg/kg Q3W
(n = 263)d
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)
EOT
40-day follow-up visit
3-month follow-up visit
BICR, blinded independent central review; DOR, duration of response; EOT, end of treatment; HEOR, health economics outcomes research; HER2, human epidermal growth factor
receptor 2; IHC, immunohistochemistry; ISH, in situ hybridization; ORR, objective response rate; OS, overall survival; PFS, progression-free survival; PRO, patient-reported outcome;
Q3W, every 3 weeks; R, randomization; T-DM1, trastuzumab emtansine; T-DXd, trastuzumab deruxtecan.
aHER2 IHC3+ or IHC2+/ISH+ based on central confirmation. Progression during or <6 months after completing adjuvant therapy involving trastuzumab and a taxane. c4 patients were
randomly assigned but not treated. d2 patients were randomly assigned but not treated. º1 cycle = 21 days; T-DXd or T-DM1 administered on day 1 of each cycle; questionnaires
completed before treatment on day 1 of cycles indicated.
ESMO BC 2022 #1630 Oral
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