Schmid, P. et. al.

Atezolizumab and Nab-Paclitaxel in Advanced Triple-Negative Breast Cancer

N Engl J Med 2018; 379:2108-2121
https://www.nejm.org/doi/full/10.1056/NEJMoa1809615

Schmid, P. et al.

IMpassion130: updated overall survival (OS) from a global, randomized, double-blind, placebo-controlled, Phase III study of atezolizumab (atezo) + nab-paclitaxel (nP) in previously untreated locally advanced or metastatic triple-negative breast cancer (mTNBC).

J Clin Oncol 37, 2019 (suppl; abstr 1003)
https://abstracts.asco.org/239/AbstView_239_252769.html

Adams, S. et al.

Patient-reported outcomes (PROs) from the phase III Impassion130 trial of atezolizumab (atezo) plus nab-paclitaxel (nP) in metastatic triple-negative breast cancer (mTNBC).

J Clin Oncol 37, 2019 (suppl; abstr 1067)
https://ascopubs.org/doi/abs/10.1200/JCO.2019.37.15_suppl.1067?af=R&

Triple negative breast cancer (TNBC) has poorer outcomes compared to hormone receptor and/or HER2- positive disease. This is in large part due to the fact that TNBC has yet to reliably respond to available treatments. Investigation continues to find cellular targets for TNBC. Those targets can then help create specific therapy for the disease.

Late last year, promising findings were published in the New England Journal of Medicine about a new treatment for metastatic TNBC (mTNBC). Atezolizumab, an agent that inhibits the cellular protection system in TNBC, was shown to improve progression-free survival when combined with nab-paclitaxel (a standard agent). The difference (7.2 months vs 5.5 months) was modest but did reach statistical significance.

Recently, at the American Society of Clinical Oncology conference, investigators presented updated information. Follow up of the same women from the original study showed that two-year overall survival among the women receiving atezolizumab and nab-paclitaxel was greater compared to women receiving nab-paclitaxel alone. While the survival was greater (42% vs 39%), the difference did not reach statistical significance.

A second presentation at the conference showed that the treatment was well-tolerated by participants, with quality of life and day-to-day function unchanged.

While this information continues to hold promise for treatment of mTNBC, critics have pointed out that the improvements among the women receiving atezolizumab are very modest. The therapy should be considered in the setting of mTNBC, but it is important to counsel patients about the apparently small benefits of azetolizumab. Further study is certainly warranted.