1.1 Trastuzumab deruxtecan is recommended for use within the Cancer Drugs Fund as an option for treating HER2‑positive unresectable or metastatic breast cancer in adults after 2 or more anti‑HER2 therapies. It is recommended only if the conditions in the managed access agreement are followed.
1.2 This recommendation is not intended to affect treatment with trastuzumab deruxtecan that was started in the NHS before this guidance was published. People having treatment outside this recommendation may continue without change to the funding arrangements in place for them before this guidance was published, until they and their NHS clinician consider it appropriate to stop.
Why the committee made these recommendations
Current treatment for HER2‑positive unresectable or metastatic breast cancer includes anti‑HER2 therapies. After 2 or more anti‑HER2 therapies, standard care is chemotherapy (such as capecitabine, vinorelbine or eribulin). Trastuzumab deruxtecan is an anti‑HER2 therapy that would be used after 2 or more anti‑HER2 therapies.
Clinical trial evidence is limited. There is a trial of trastuzumab deruxtecan on its own, which means it is not directly compared with any other treatments. Indirect comparisons of trastuzumab deruxtecan with chemotherapy suggest that it may increase how long before disease progresses and how long people live. However, how much longer people live is uncertain because there are differences between trials included in the indirect comparisons, and the final data from the trial of trastuzumab deruxtecan on its own is not available yet. Because of this, the estimates of cost effectiveness are very uncertain and trastuzumab deruxtecan cannot be recommended for routine use in the NHS.
Trastuzumab deruxtecan could be cost effective if further data shows that people live longer with treatment. Another ongoing trial is directly comparing trastuzumab deruxtecan with anti‑HER2 therapies plus chemotherapy. Data from the trials of trastuzumab deruxtecan and from NHS practice would help address the uncertainty about clinical effectiveness. Trastuzumab deruxtecan is therefore recommended for use in the Cancer Drugs Fund.