For Immunotherapy in TNBC, Nab-paclitaxel Is a Must

This transcript has been edited for clarity.

Hi. It's Dr Kathy Miller, back with our second installment of "Good Science That Makes You Think."

Previously, we saw early results of the IMpassion130 trial, a randomized trial of patients with newly identified metastatic triple-negative breast cancer (TNBC) randomized to either nab-paclitaxel alone or nab-paclitaxel with atezolizumab. And we've talked about the design of this trial before. It clearly showed a significant improvement in progression-free survival. The overall survival results — even updated at this [European Society for Medical Oncology (ESMO)] meeting — require caution in their interpretation. There is roughly a 7- to 7.5-month improvement in overall survival in the PD-L1-positive cohort with the addition of atezolizumab. But the study design does not allow us to conclude or to even know if that difference was statistically significant.

Now, at this year's ESMO meeting, we saw the first results of the IMpassion131 trialIt had a very similar design with newly identified metastatic TNBC patients randomized to a taxane or a taxane with atezolizumab. But in this case, the taxane was paclitaxel. And there was no difference [in outcomes] in the overall population, and no obvious difference in the PD-L1-positive population. How could that be? We tend to think of Abraxane as just a taxane in a different packaging; it does not need Cremophor, and therefore it does not need steroids. How could these two different trials using a similar chemotherapy backbone come to such different results?