Table 4 Safety data by hormone receptor status and ADC sequence order
HR + /HER2-low MBC (n = 56) | HR-/HER2-low MBC (n = 28) | |||
|---|---|---|---|---|
ADC sequence order | SG → TDXd | TDXd → SG | SG → TDXd | TDXd → SG |
During treatment with SG | SG as ADC1 (n = 24) | SG as ADC2 (n = 32) | SG as ADC1 (n = 25) | SG as ADC2 (n = 3) |
Required SG dose reduction | 10 (41.6%) | 19 (59.4%) | 11 (44.0%) | 1 (33.3%) |
Due to lab abnormalities | 6 (25.0%) | 12 (37.5%) | 7 (28.0%) | 1 (33.3%) |
Due to symptoms | 4 (16.7%) | 4 (12.5%) | 4 (16.0%) | 0 |
Due to other reasons | 0 | 3 (9.4%) | 0 | 0 |
Discontinued SG due to toxicity | 3 (12.5%) | 4 (12.5%) | 1 (4.0%) | 0 |
Received growth factor support during SG | 14 (58.3%) | 21 (65.6%) | 17 (68.0%) | 1 (33.3%) |
Primary prophylaxis | 7 (29.2%) | 13 (40.6%) | 10 (40.0%) | 0 |
Secondary prophylaxis | 7 (29.2%) | 8 (25.0%) | 7 (28.0%) | 1 (33.3%) |
Treatment delay due to neutropenia | 4 (16.7%) | 6 (18.8%) | 6 (24.0%) | 0 |
During treatment with T-DXd | T-DXd as ADC2 (n = 24) | T-DXd as ADC1 (n = 32) | T-DXd as ADC2 (n = 25) | T-DXd as ADC1 (n = 3) |
Required T-DXd dose reduction | 4 (16.7%) | 8 (25.0%) | 3 (12.0%) | 0 |
Due to lab abnormalities | 0 | 2 (6.3%) | 2 (8.0%) | 0 |
Due to symptoms | 2 (8.3%) | 3 (9.4%) | 0 | 0 |
Due to other reason(s) | 2 (8.3%) | 3 (9.4%) | 1 (4.0%) | 0 |
Discontinued T-DXd due to toxicity | 2 (8.3%) | 4 (12.5%) | 4 (16.0%) | 0 |
Received growth factor support during SG | 3 (12.5%) | 3 (9.4%) | 2 (8.0%) | 0 |
Primary prophylaxis | 3 (12.5%) | 2 (6.3%) | 2 (8.0%) | 0 |
Secondary prophylaxis | 0 | 1 (3.1%) | 0 | 0 |
Treatment delay due to neutropenia | 0 | 2 (6.3%) | 0 | 0 |
Diagnosed with any grade ILD/ pneumonitis | 2 (8.3%) | 7 (21.9%) | 5 (20.0%) | 0 |
Grade 1–2 | 0 | 7 (21.9%) | 0 | 0 |
Grade 3–4 | 1 (4.2%) | 0 | 3 (12.0%) | 0 |
Grade 5 | 1 (4.2%) | 0 | 2 (8.0%) | 0 |
