HER2 ultra-low Metastatic Breast Cancer Patients
with HR+/HER2-low or HR+/HER2-ultralow mBC1 DESTINY-Breast06 has expanded
the potential eligibility for HER2-directed therapy
to a new group of patients1
~85-90% of patients with HR+/HER2-negative mBC may have actionable levels of HER2,
as demonstrated in DESTINY-Breast06 screening data2,a
aAmong the 1856 patients included in the study, 12%
(225 patients) had IHC 0 with absent membrane staining, while
22% (402 patients) were classified as HER2-ultralow, defined
as IHC 0 with membrane staining.
IHC 1+ was observed in 45%
(829 patients), and IHC 2+/ISH– in 21% (385 patients).2
(March 2024)
Primary endpoint: PFS (by BICR) in the HER2-low mBC population
Adapted from Bardia A, et al, N Engl J Med. 2024
- Median follow-up: 18.6 months4
- Overall survival data were immature (39%)
at the time of analysis3,4
(HR: 0.62; 95% CI: 0.52, 0.75; P<0.0001)3
(March 2024)
Median PFS, months
Consistent results in patients after 1L ET ± targeted therapy for mBC and progression ≤6 months after starting 1L ET + CDK4/6i
or recurrence ≤24 months of starting adjuvant ET3
Size of circle is proportional to the number of events. Data show
results of an exploratory analysis; subgroups were chosen based
on DESTINY-Breast06 stratification factors.3,5 Pre-specified
subgroup analyses were not
tested for statistical significance and
not powered to show a difference between treatment arms.3
aBased on central laboratory data (ie, most recent evaluable
sample prior to randomization).3 bSpecified by investigator prior
to randomization.3
(March 2024)
ORR and DOR were not tested for statistical significance, and the study was not powered to show differences between treatment arms.3
Response rates with ENHERTU and chemotherapy (secondary endpoint)3
ORR and DOR were not tested for statistical significance, and the study was not powered to show differences between treatment arms.3
Abbreviations: BICR, blinded independent central review;
CBR, clinical benefit rate; CR, complete response;
CI, confidence interval; DOR, duration of response;
HER2, human epidermal growth factor receptor 2;
HR, hazard ratio; HR+, hormone receptor-positive;
IHC, immunohistochemistry; ISH, in situ
hybridization; mBC, metastatic breast cancer; mPFS,
median progression-free survival; ORR, objective
response rate; PR, partial response; SD, stable
disease.
References:
- Enhertu Malaysia Prescribing Information.
- Viale G, et al. DESTINY-Breast06 Investigators.
HER2-low and HER2-ultralow status
determination in tumors of patients with
hormone
receptor-positive metastatic breast
cancer in DESTINY-Breast06. Presented at:
European Society for Medical Oncology;
September 13-17, 2024; Barcelona, Spain. - Bardia A, et al. N Engl J Med.
2024;391(22):2110-2122. - Curigliano G. Trastuzumab deruxtecan vs
physician’s choice of chemotherapy in patients
with hormone receptor-positive, human
epidermal growth factor receptor 2 (HER2)-low
or HER2-ultralow metastatic breast cancer with
prior endocrine therapy: primary results from
DESTINY-Breast06. Presented at: American
Society for Clinical Oncology; May 31-June 4,
2024; Chicago, IL. - Bardia A, et al. N Engl J Med.
2024;391(22):2110-2122; Protocol.
