Kathy Miller on IMpassion130: Immunotherapy a New Standard in Breast Cancer? Not Yet

Hi. This is Dr Kathy Miller with Indiana University. I wanted to get right to the details of the IMpassion130 trial,^[1] reported recently at the European Society for Medical Oncology (ESMO) 2018 meeting. You'll recall hearing about that trial by press release a couple of months ago as a positive trial, meeting its primary endpoint. We're now able to look at the details together.

To remind you, this was a large trial of just over 900 patients with metastatic triple-negative breast cancer. Participants could have received adjuvant or neoadjuvant therapy but no previous treatment for metastatic disease. They were randomly assigned to receive nab-paclitaxel (chosen to avoid the need for steroid premedication) with placebo or atezolizumab, one of the PD-L1-targeted agents. Patients were stratified on the basis of their extensive disease, previous chemotherapy, and PD-L1 status. There were defined subsets for the PD-L1-positive patients, which was about 41% of the total subset.

The trial design gets very complicated. There were co-primary endpoints of progression-free survival and overall survival in the entire population, and then separately in the PD-L1-positive group. Now, because of this design, the investigators were required to test those endpoints in the entire study population, and only if that was positive could they then look at the PD-L1-positive group.