Dr Simon Vincent, director of research, support and influencing at Breast Cancer Now, said:
"This promising study suggests even more people could potentially benefit from Enhertu, offering patients with HER2-low or HER2-ultralow* secondary breast cancer who have already had hormone-based therapy more time to live without their cancer spreading further.**
“This builds on existing evidence that this treatment can increase overall survival by over six months for people with HER2-low secondary breast cancer who have already had chemotherapy.
"Yet, despite this mounting clinical data emerging around the clear benefit Enhertu could bring patients, thousands of people with HER2-low secondary breast cancer are being denied access to Enhertu on the NHS in England, and this is utterly unacceptable.*** These people are desperately counting on NICE, NHS England, Daiichi Sankyo and AstraZeneca to find a solution in their current talks and to urgently make this treatment available for them.”
Ends
Notes to editors
- *According to the American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP), the HER2 test positivity is defined by protein overexpression (score 3+) at immunohistochemistry (IHC) and/or gene amplification at in situ hybridization (ISH). The introduction of novel anti-HER2 compounds, however, is changing this paradigm because some breast cancers with lower levels of protein expression (i.e. score 1+/2+ with no gene amplification) benefited from HER2 antibody-drug conjugates (ADC). Recently, a potential for HER2 targeting in HER2 “ultra-low” (i.e. score 0 with incomplete and faint staining in ≤10% of tumor cells) and MutL-deficient estrogen receptor (estrogen receptor)-positive/HER2-negative breast cancers has been highlighted.
- **DB-06 (NCT04494425) evaluated T‑DXd in pts with HER2-low or -ultralow (IHC 0 with membrane staining), HR+ mBC after disease progression (PD) on endocrine-based therapy and no prior CT for mBC. T-DXd showed a statistically significant and clinically meaningful PFS benefit vs TPC (CT) in HER2-low mBC. HER2-ultralow results were consistent with HER2-low.
- ***NICE has rejected Enhertu for patients with HER2-low secondary breast cancer after chemotherapy for use on the NHS in England. This decision will also likely affect patients in Wales and Northern Ireland as they usually follow NICE decisions. It has been approved for use on the NHS in Scotland.
- Enhertu is available on the NHS for patients with HER2 positive secondary breast cancer after one or more lines of anti-HER2 therapy.
- Secondary (or metastatic) breast cancer occurs when breast cancer cells spread from the primary (first) cancer in the breast to other parts of the body. It is treatable but incurable.