Table 1 Characteristics of patients/disease at baseline

Age, years

55 (46–64)

53 (44–63)

53 (40–60)

 Distribution – no. (%)

  18–40

63 (14%)

31 (17%)

6 (30%)

  41–64

284 (63%)

111 (60%)

10 (50%)

  ≥ 65

104 (23%)

43 (23%)

4 (20%)

Sex

 Female

448 (99%)

184 (99%)

19 (95%)

 Male

3 (1%)

1 (1%)

1 (5%)

Baseline disease status

Metastatic

404/450 (90%)

162/185 (88%)

19 (95%)

Number of metastatic sites

 0–3

332/450 (74%)

149/185 (81%)

15 (75%)

 ≥ 4

118/450 (26%)

36/185 (19%)

5 (25%)

Site of metastatic disease

 Liver

126 (28%)

44 (24%)

8 (40%)

 Bone

145 (32%)

54 (29%)

6 (30%)

 Brain

30 (7%)

15 (8%)

4 (20%)

  asymptomatic, treated

1 (5%)

  symptomatic, treated

3 (15%)

 Lung

226 (51%)

86 (46%)

11 (55%)

 Lymph node only

33/450 (7%)

18/185 (10%)

0

Previous neoadjuvant or adjuvant treatment

284 (63%)

125 (68%)

15 (75%)

Previous taxane use^a

231 (51%)

96 (52%)

14 (70%)

Previous anthracycline use^a

243 (54%)

109 (59%)

14 (70%)

Previous radiotherapy^a

268 (59%)

119 (64%)

12 (60%)

Radiotherapy of the brain

25 (6%)

14 (8%)

3 (15%)

Time from last surgery until diagnosis with unresectable locally advanced or metastatic disease, months^c

24.5 (15.9–38.9)

21.5 (15.0–36.2)

9.0 (6.2–22.5)

Treatment line for metastatic disease

 I

9 (45%)

 II

3 (15%)

 III

4 (20%)

 IV

2 (10%)

 V

2 (10%)

Number of subsequent treatment lines following atezolizumab (and nab-paclitaxel) discontinuation at the time of data cut-off

 1

4 (22%)

 2

6 (33%)

 3

2 (11%)

Unknown

2 (11%)

PD-L1 status

 PD-L1 positive

17 (85%)

 PD-L1 negative

2 (10%)

PD-L1 biopsy site

 Breast

576 (63.9%)^d

9 (45%)

 Lymph nodes^b

109 (12.1%)^d

5 (25%)

 Skin

21 (2.3%)^d

6 (30%)

 Liver

47 (5.2%)^d

1 (5%)

 Peritoneum

Unknown

1 (5%)

 Brain

9 (1%)^d

2 (10%)

 Lung

54 (6%)^d

0

 Soft tissue

39 (4.3%)^d

0

 Other

46 (5.1%)^d

0