Table 2.
Regimens used in 2L following 1L pertuzumab and trastuzumab-based regimens
| Total (N = 222) | Without BMa (n = 172) | With BMa (n = 50) | |
|---|---|---|---|
| T-DM1-based regimen | 159 (71.6%) | 124 (72.1%) | 35 (70.0%) |
| T-DM1 only | 96 (43.2%) | 70 (40.7%) | 26 (52.0%) |
| T-DM1 + chemotherapy ± hormonal therapy | 23 (10.4%) | 19 (11.0%) | 4 (8.0%) |
| T-DM1 + hormonal therapy | 30 (13.5%) | 25 (14.5%) | 5 (10.0%) |
| T-DM1 + othera | 10 (4.5%) | 10 (5.8%) | – |
| Trastuzumab-based regimen | 3 (1.4%) | 3 (1.7%) | – |
| Trastuzumab + chemotherapy ± hormonal therapy | 2 (0.9%) | 2 (1.2%) | – |
| Trastuzumab + hormonal therapy | 1 (0.5%) | 1 (0.6%) | – |
| Trastuzumab + pertuzumab-based regimen | 3 (1.4%) | 2 (1.2%) | 1 (2.0%) |
| Trastuzumab + pertuzumab | 1 (0.5%) | 1 (0.6%) | – |
| Trastuzumab + pertuzumab + chemotherapy ± hormonal therapy | 2 (0.9%) | 1 (0.6%) | 1 (2.0%) |
| TKI-based regimen | 39 (17.6%) | 26 (15.1%) | 13 (26.0%) |
| Lapatinib-based regimen | 21 (9.5%) | 11 (6.4%) | 10 (20.0%) |
| Lapatinib + capecitabine ± hormonal therapy | 11 (5.0%) | 7 (4.1%) | 4 (8.0%) |
| Lapatinib + trastuzumab + pertuzumab | 5 (2.3%) | 2 (1.2%) | 3 (6.0%) |
| Trastuzumab + lapatinib + chemotherapy ± hormonal therapy | 2 (0.9%) | 1 (0.6%) | 1 (2.0%) |
| Trastuzumab + lapatinib | 1 (0.5%) | – | 1 (2.0%) |
| Lapatinib only | 1 (0.5%) | 1 (0.6%) | – |
| Lapatinib + otherb | 1 (0.5%) | – | 1 (2.0%) |
| Neratinib-based regimen | 18 (8.1%) | 15 (8.7%) | 3 (6.0%) |
| Neratinib | 13 (5.9%) | 11 (6.4%) | 2 (4.0%) |
| Neratinib + trastuzumab + pertuzumab | 3 (1.4%) | 2 (1.2%) | 1 (2.0%) |
| Neratinib + trastuzumab | 2 (0.9%) | 2 (1.2%) | |
| Other anti-HER2 regimens | 10 (4.5%) | 9 (5.2%) | 1 (2.0%) |
| Trastuzumab + pertuzumab + T-DM1 | 8 (3.6%) | 7 (4.1%) | 1 (2.0%) |
| Trastuzumab + T-DM1 | 2 (0.9%) | 2 (1.2%) | – |
| Other regimens | 8 (3.6%) | 8 (4.7%) | – |
| Chemotherapy + hormonal therapy | 2 (0.9%) | 2 (1.2%) | – |
| Hormonal therapy only | 2 (0.9%) | 2 (1.2%) | – |
| I/O or OTT only | 4 (1.8%) | 4 (2.3%) | – |
1L first line, 2L second line, BM brain metastases, HER2 human epidermal growth factor receptor 2, I/O immuno-oncology therapy, OTT other targeted therapy, T-DM1 ado-trastuzumab emtansine, TKI tyrosine kinase inhibitor
aBM was identified before 2L initiation; b‘Other’ includes OTT and/or I/O with or without chemotherapy and/or hormonal therapy