Table 2.

Immune checkpoint inhibitors in primary breast cancer

Study	Phase	Checkpoint inhibitor	Chemotherapy	Population	No. of patients	pCR (ypT0/is and ypN0)
I-SPY 243	2	Pembrolizumab	Paclitaxel or paclitaxel/pembro followed by doxorubicin/cyclophosphamide	TNBC ; HR+/HER2- ; PD-L1 unselected ; tumour size > 2.5 cm; mammaprint high risk (nodal involvement in 37.7% pembro, 43.9% control)	69 pembro, 180 control	TNBC: 60% pembro vs. 20% controla HR+/HER2-: 34% pembro vs. 13% controla
KEYNOTE-17341	1b	Pembrolizumab	A: pembro followed by pembro + nab-paclitaxel followed by pembro + doxorubicin/cyclophosphamide . B: pembro followed by pembro + nab-paclitaxel + carboplatin followed by pembro + doxorubicin/cyclophosphamide	TNBC ; PD-L1 unselected ; locally advanced (primary tumour stage ≥T2 in 90%, nodal involvement in 75%)	20	Cohort A, 60%; Cohort B, 90%
Pusztai et al.42	1	MEDI4736	MEDI4736 + nab-paclitaxel followed by dose dense doxorubicin/cyclophosphamide	TNBC ; PD-L1 unselected; stage I-III (primary tumour stage ≥T2 in 57%, nodal involvement in 57%)	7	71.4%

Recently presented studies of anti-PD1/PD-L1 agents in neoadjuvant breast cancer therapy.

pCR pathological complete response.

^aEstimated pCR