1.1 Trastuzumab emtansine is recommended, within its marketing authorisation, as an option for the adjuvant treatment of human epidermal growth factor receptor 2 (HER2)‑positive early breast cancer in adults who have residual invasive disease in the breast or lymph nodes after neoadjuvant taxane-based and HER2‑targeted therapy. It is recommended only if the company provides trastuzumab emtansine according to the commercial arrangement.
Why the committee made these recommendations
Neoadjuvant therapy aims to reduce the size of the tumour before surgery. It sometimes shrinks completely, but people may still have cancer remaining when they have their surgery (residual invasive disease). The cancer may have spread to lymph nodes in the armpit (node-positive disease).
Adjuvant treatment aims to reduce the risk of cancer returning after surgery. Trastuzumab is an adjuvant treatment for people with node-negative or node-positive disease. Pertuzumab plus trastuzumab with chemotherapy is an adjuvant treatment for node-positive disease but not for node-negative disease. Trastuzumab emtansine would be an alternative adjuvant treatment for people with node-negative or node-positive disease.
Clinical trial evidence shows that in people with residual invasive disease after neoadjuvant therapy and surgery, trastuzumab emtansine increases the time people remain free of disease compared with trastuzumab alone. We do not know if trastuzumab emtansine increases the length of time people live because the final trial results are not yet available. An indirect comparison in people with node-positive disease suggests that trastuzumab emtansine increases the time until cancer progresses compared with pertuzumab plus trastuzumab with chemotherapy, but this is uncertain because there are differences between people in the 2 trials.
The cost-effectiveness estimates are within what NICE considers an acceptable use of NHS resources. Therefore, trastuzumab emtansine is recommended.