HER2-low & HER2-ultralow Efficacy Data

In patients with HR+/HER2-low (IHC 1+ or IHC 2+/ISH–) and HER2-ultralow (IHC 0 with membrane staining) mBC

ENHERTU provided 13.2 months median PFS vs 8.1 months with chemotherapy1,2

Median PFS in the overall study population (HER2-low and HER2-ultralow; secondary endpoint)

KM curve depicting (13.2 months mPFS) with ENHERTU compared to (8.1 months mPFS) with chemotherapy in the overall study population, which included patients with HR+/HER2-low mBC (IHC 1+ or IHC 2+/ISH–) or HER2-ultralow (IHC 0 with membrane staining) KM curve depicting (13.2 months mPFS) with ENHERTU compared to (8.1 months mPFS) with chemotherapy in the overall study population, which included patients with HR+/HER2-low mBC (IHC 1+ or IHC 2+/ISH–) or HER2-ultralow (IHC 0 with membrane staining)

36% reduction in the risk of disease progression or death with ENHERTU (HR=0.64; 95% CI: 0.54, 0.76; P<0.0001)1,a

aBased on unstratified analysis.

Over 60% ORR with ENHERTU and 34.4% with chemotherapy1,2,b

Confirmed objective response in the overall study population (HER2-low and HER2-ultralow; secondary endpoint; N=866)

Bar chart (62.6% ORR) with ENHERTU and (34.4% ORR) with chemotherapy in the overall study population, which included patients with HR+/HER2-low mBC (IHC 1+ or IHC 2+/ISH-) or HER2-ultralow (IHC 0 with membrane staining) Bar chart (62.6% ORR) with ENHERTU and (34.4% ORR) with chemotherapy in the overall study population, which included patients with HR+/HER2-low mBC (IHC 1+ or IHC 2+/ISH-) or HER2-ultralow (IHC 0 with membrane staining)
  • mDOR was 14.3 months with ENHERTU and 8.6 months with chemotherapy1,b
  • ORR and DOR were not tested for statistical significance and were not powered to show differences between treatment arms. Therefore, the clinical significance of these data is not known

Additional results

  • 77.1% clinical benefit rate (CBR) (CR+PR+SD at week 24) with ENHERTU (n=303/393) and 50.9% with chemotherapy (n=198/389)3

OVER 90% (n=362/393) of patients achieved disease control (CR+PR+SD) with ENHERTU3,c

  • CBR and DCR were not tested for statistical significance and were not powered to show differences between treatment arms. Therefore, the clinical significance of these data is not known

bAnalysis was performed based on the patients with measurable disease assessed by BICR at baseline.

cDCR was 92.1% with ENHERTU (n=362/393) and 80.5% with chemotherapy (n=313/389).3

The results of DESTINY-Breast06 extend the potential benefits of HER2-directed therapy to patients with HR+/HER2-ultralow mBC

Summary of DESTINY-Breast06 efficacy results by patient population1

Table depicting the summary of the DESTINY-Breast06 efficacy results by patient population. Overall study population (N=866), HER2-low  (IHC 1+ or IHC 2 +/ISH-) cohort (n=713), and Exploratory HER2-ultralow (IHC 0 with membrane staining) cohort (n=153). Table depicting the summary of the DESTINY-Breast06 efficacy results by patient population. Overall study population (N=866), HER2-low  (IHC 1+ or IHC 2 +/ISH-) cohort (n=713), and Exploratory HER2-ultralow (IHC 0 with membrane staining) cohort (n=153).
  • ORR was not tested for statistical significance and was not powered to show differences between treatment arms. Therefore, the clinical significance of these data is not known

mPFS in the exploratory HER2-ultralow (IHC 0 with membrane staining) cohort (n=153)1,3

Table depicting the summary of the DESTINY-Breast06 efficacy results by patient population. Overall study population (N=866), HER2-low  (IHC 1+ or IHC 2 +/ISH-) cohort (n=713), and Exploratory HER2-ultralow (IHC 0 with membrane staining) cohort (n=153). Table depicting the summary of the DESTINY-Breast06 efficacy results by patient population. Overall study population (N=866), HER2-low  (IHC 1+ or IHC 2 +/ISH-) cohort (n=713), and Exploratory HER2-ultralow (IHC 0 with membrane staining) cohort (n=153).
  • ORR in the exploratory HER2-ultralow cohort was 65.7% (n=44/67; 95% CI: 53.1, 76.8) with ENHERTU and 30.8% (n=20/65; 95% CI: 19.9, 43.4) with chemotherapy1,f
  • The HER2-ultralow cohort was an exploratory population. The data are descriptive and were not tested for statistical significance, nor powered to show a difference between treatment arms. Therefore, the clinical significance of these data is not known

dBased on unstratified analysis.

eBased on stratified analysis with stratification factors prior CDK4/6 inhibitor use (yes vs no) and HER2 IHC status of tumor samples (IHC 1+ vs IHC 2+/ISH–).

fAnalysis was performed based on the patients with measurable disease assessed by BICR at baseline.

ADDITIONAL DATA

In patients with HR+/HER2-low (IHC 1+ or IHC 2+/ISH–) and HER2-ultralow (IHC 0 with membrane staining) mBC

Results observed with ENHERTU in select exploratory patient subgroups in the overall study population1,4,5

EXPLORATORY POST-HOC ANALYSIS
  • These subgroup data are based on an exploratory post-hoc analysis; they were not tested for statistical significance and not powered to show differences between treatment arms or between subgroups. Therefore, the clinical significance of these data is not known

Median PFS: select subgroup results in the overall study population3,4

EXPLORATORY POST-HOC ANALYSIS
  • These subgroup data are based on an exploratory post-hoc analysis; they were not tested for statistical significance and not powered to show differences between treatment arms or between subgroups. Therefore, the clinical significance of these data is not known

Confirmed ORR: select subgroup results in the overall study population (BICR)5,h

Capecitabine (60% of patients)

Taxanes (40% of patients)

gMedian baseline tumor size in the ITT population (per BICR) was 48.6 mm, considering “0” as baseline tumor size for patients without target lesion at baseline.

hENHERTU and chemotherapy subgroups were matched by physician's choice of chemotherapy before randomization.

NCCN GUIDELINES® PREFERRED

NCCN CLINICAL PRACTICE GUIDELINES IN ONCOLOGY (NCCN Guidelines®)
recommended option for eligible patients with HR+ mBC who have low levels of HER2

NCCN Guidelines® recommends fam-trastuzumab deruxtecan-nxki (ENHERTU) for recurrent unresectable (local or regional) or stage IV HER2– breast cancer as an NCCN Category 2A, 1L other recommended option for patients with HR-positive disease who are in visceral crisis or are endocrine refractory with tumors that are HER2 IHC 0+, 1+, or 2+/ISH-negative and have no germline BRCA1/2 mutation6,i-k

RECOMMENDED IN NCCN CLINICAL PRACTICE GUIDELINES IN ONCOLOGY (NCCN GUIDELINES®)

NCCN Guidelines® recommended option for eligible patients with HR+ mBC who have low levels of HER2

NCCN Guidelines recommends fam-trastuzumab deruxtecan-nxki (ENHERTU) for recurrent unresectable (local or regional) or stage IV HER2– breast cancer as an NCCN Category 2A, 1L other recommended option for patients with HR-positive disease who are in visceral crisis or are endocrine refractory with tumors that are HER2 IHC 0+, 1+, or 2+/ISH-negative and have no germline BRCA1/2 mutation6,i-k

iIHC 0+ refers to tumors with faint, partial membrane staining in ≤10% of tumor cells.

jAssess for germline BRCA1/2 mutations in all patients with recurrent or metastatic breast cancer to identify candidates for PARPi therapy.

kThe distinction between HER2 test results of IHC 0/absent membrane staining, IHC 0+/with membrane staining (faint, partial membrane staining in ≤10%), IHC 1+, or 2+/ISH negative is currently clinically relevant for therapy selection.

1L, first line; BICR, blinded independent central review; BRCA1/2, BReast CAncer gene 1 or 2; CBR, clinical benefit rate; CDK4/6, cyclin-dependent kinases 4 and 6; CI, confidence interval; CR, complete response; DCR, disease control rate; DOR, duration of response; HER2, human epidermal growth factor receptor 2; HR, hazard ratio; HR+, hormone receptor-positive; IHC, immunohistochemistry; ISH, in situ hybridization; ITT, intent-to-treat; mBC, metastatic breast cancer; mDOR, median duration of response; mPFS, median progression-free survival; NCCN, National Comprehensive Cancer Network® (NCCN®); ORR, objective response rate; PFS, progression-free survival; PR, partial response; SD, stable disease.