Table 2.

Published trials of immune checkpoint inhibitors in metastatic breast cancer.

TrialPhase/agent/name	Included patients with BM	Evaluable patients	Patients with BCBM, n (%)
Phase Ib. Pembrolizumab. Keynote-01287	Yes. Treated and stable BM	32	3 (9.4%)
Phase Ia. Atezolizumab88	Yes. Asymptomatic BM	115	N/A
Phase Ib. Avelumab. JAVELIN89	No	168	0
Phase Ib. Pembrolizumab. Keynote-02890	Yes. Treated and stable BM	25	N/A
Phase II. Pembrolizumab. Keynote-086 (Cohort A)91	No	170	0
Phase II. Pembrolizumab. Keynote-086 (Cohort B)92	No	84	0
Phase III. Pembrolizumab + chemotherapy. Keynote-35593	Yes. Treated and stable BM	847	26 (3%)
Phase I. Atezolizumab + nab-paclitaxel94	Yes. Treated and stable BM	33	N/A
Phase III. Atezolizumab + nab-paclitaxel. Impassion13095	Yes. Treated and stable BM	902	61 (6.7%)
Phase I. Pembrolizumab + eribulin mesylate. ENHANCE196	Yes. Treated and stable BM	82	1 (1.2%)
Phase Ib. pembrolizumab + abemaciclib. JPCE97	Yes. Asymptomatic BM	28	N/A
Phase II (Basket trial). Durvalumab + olaparib, MEDIOLA98	Yes. Asymptomatic BM	32	N/A
Phase II. Niraparib + pembrolizumab. TOPACIO99	Yes. Treated BM	47	N/A
Phase I/II. Pembrolizumab + trastuzumab. PANACEA100	Yes. Stable BM	58	N/A
Phase II. TDM1 + pembrolizumab. KATE2101	No	69	0
Total		2692	91 (3.3%)

Abbreviations: BM, brain metastases; N/A, not available.