Table 3 Treatment regimens and safety outcomes of neoadjuvant chemotherapy plus pembrolizumab according to AC (doxorubicin and cyclophosphamide) regimen (N = 311)

G-CSF, N (%)

53 (40.7%)

177 (98.8%)

<0.001

Number of neoadjuvant pembrolizumab cycles

0.020

< 6

17 (13.1%)

43 (23.9%)

6 or more

113 (86.9%)

137 (76.1%)

Reasons for less than 6 cycles of pembrolizumab

0.001

Regulatory/ insurance

7 (5.3%)

31 (17.1%)

Toxicity

13 (10%)

27 (14.9%)

Other

11 (8.3%)

19 (10.5%)

Sequence between AC and carboplatin-paclitaxel

0.002

Carboplatin-paclitaxel first

103 (90.3%)

124 (75.6%)

AC first

11 (9.6%)

40 (24.4%)

Carboplatin schedule

0.366

Weekly

103 (94.5%)

152 (96.8%)

Every 3-week

6 (5.5%)

5 (3.2%)

Drug discontinuation during NACT

26 (20.1%)

45 (25.1%)

0.339

Pembrolizumab

11 (8.4%)

22 (12.1%)

0.353

Carboplatin

11 (8.4%)

23 (12.7%)

0.272

Paclitaxel

4 (3%)

8 (4.4%)

0.767

Doxorubicin

6 (4.6%)

10 (5.6%)

0.799

Cyclophosphamide

6 (4.6%)

10 (5.6%)

0.799

Dose reduction

19 (14.8%)

23 (12.8%)

0.618

Carboplatin

8 (6.1%)

3 (1.6%)

0.057

Paclitaxel

8 (6.1%)

8 (4.4%)

0.605

Doxorubicin

8 (6.1%)

13 (7.1%)

0.821

Cyclophosphamide

7 (5.3%)

10 (5.5%)

1.000

Delay > 7 days for treatment conclusion

28 (21.8%)

50 (28%)

0.234

Use of antibiotics

31 (24.4%)

57 (31.8%)

0.162

Grade 3-4 toxicity

39 (30.7%)

73 (40.5%)

0.092

Anemia

3 (2.3%)

7 (3.8%)

0.529

Neutropenia

27 (20.7%)

46 (25.4%)

0.416

Febrile neutropenia

12 (9.2%)

29 (16%)

0.091

Thrombocytopenia

0 (0%)

2 (1.1%)

0.512

Nausea

0 (0%)

5 (2.7%)

0.077

Vomiting

0 (0%)

5 (2.7%)

0.077

Diarrhea

4 (3%)

4 (2.1%)

0.724

ASL/ALT elevation

1 (0.7%)

8 (4.4%)

0.085

Immune-related toxicity

9 (6.9%)

15 (8.2%)

0.830