What is ENHERTU?
ENHERTU is a prescription medicine used to treat adults who have human epidermal growth factor receptor 2 (HER2)-positive breast cancer that cannot be removed by surgery or that has spread to other parts of the body (metastatic), and who have received a prior anti-HER2 breast cancer treatment for metastatic disease, or have breast cancer that has come back during or within 6 months of completing treatment for their early-stage breast cancer.
How was ENHERTU studied in HER2+ mBC?
ENHERTU was studied in many types of adults, including those with different:
- Hormone receptor (HR) status
- Tumors that had spread (metastasized) to other parts of the body, including the liver, lungs, and bone
- Tumors that had spread to the brain and were stable
ENHERTU was compared with Kadcyla® (ado-trastuzumab emtansine) in a clinical trial of 524 people who:
- Had HER2+ breast cancer that had spread to other parts of their body or could not be removed by surgery, and
- Had received a prior treatment for HER2+ metastatic breast cancer or had cancer come back during or within 6 months of treatment after surgery
In this trial, 261 people were treated with ENHERTU and 263 were treated with Kadcyla.
What were the results of the ENHERTU study?
*174 out of 261 people treated with ENHERTU lived without their cancer progressing or them dying at the time of follow-up compared to 105 out of 263 people treated with Kadcyla.
†Median progression-free survival (mPFS) was not reached with ENHERTU at the time it was assessed, and mPFS for people taking Kadcyla was about 7 months. Median progression-free survival is the length of time from the start of treatment that half of the people in the study had gone without disease progression. When more than half of the people had lived without disease progression, mPFS had not been reached.
At 12 months, 150 patients remained on ENHERTU and 51 patients remained on Kadcyla.
Almost 83% of people had their tumors shrink with ENHERTU and 36% with Kadcyla‡§
More than 8 out of 10 people
responded to ENHERTU
More than 3 out of 10 people
responded to Kadcyla
This is called overall response rate.
Of the people who responded to ENHERTU:
- 16% of people achieved a complete response with ENHERTU and 8% treated with Kadcyla.‡|| A complete response means the tumor could not be seen on imaging tests
- 67% of people achieved a partial response with ENHERTU and 28% treated with Kadcyla.‡¶ A partial response means the tumor shrank by at least 30%
- 15% of people achieved stable disease with ENHERTU and 40% treated with Kadcyla.# This means that people did not have their tumor increase in size by more than 20% or decrease in size by more than 30%
‡Not statistically significant. Statistical significance describes a mathematical measure of difference between groups. The difference is statistically significant if it is greater than what might be expected to happen by chance alone.
§205 of 248 people had their tumors shrink with ENHERTU and 87 of 241 people with Kadcyla.
||39 of 248 achieved a complete response with ENHERTU and 20 of 241 people with Kadcyla.
¶166 of 248 achieved a partial response with ENHERTU and 67 of 241 people with Kadcyla.
#37 of 248 achieved stable disease with ENHERTU and 97 of 241 people with Kadcyla.
Nearly 98% of people treated with ENHERTU had their tumor(s) respond to treatment in at least 1 of the following ways:
This is called the disease control rate**
A variety of patients with HER2+ mBC responded to ENHERTU.
**The disease control rate is the percentage of patients who have achieved complete response, partial response, or stable disease. 242 of 248 people treated with ENHERTU achieved disease control.
HR, hormone receptor.
HER2, human epidermal growth factor 2; HR, hormone receptor; mBC, metastatic breast cancer.