Neoadjuvant antibody-drug conjugates for early-stage breast cancer: A systematic review and meta-analysis.
Gabriela Barbosa E Silva, Anderson Ruiz Simões, Rafael Lara Nohmi et al.
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In 30 seconds
This systematic review and random-effects meta-analysis assessed neoadjuvant antibody-drug conjugates (ADCs), alone or in combination, in early-stage breast cancer. Twenty-four studies were included; 22 studies, comprising 2363 patients, contributed to the pathologic complete response (pCR) analysis. The pooled pCR rate was 38.34% (95% CI 29.36-47.72; I² = 92.8%), with rates varying by tumour subtype and highest in HR-negative/HER2-positive disease (65.06%). Grade ≥ 3 adverse events occurred in 25.06% of patients. The authors conclude that ADC-based strategies warrant further investigation, including biomarker-guided selection.
Key findings
- Across 22 studies and 2363 patients, the pooled pCR rate was 38.34% (95% CI 29.36-47.72; I² = 92.8%).
- pCR rates ranged from 65.06% in HR-negative/HER2-positive tumours to 2.94% in HR-positive/HER2-negative tumours (p < 0.0001).
- By ADC target, pCR rates were 43.93% for HER2, 41.41% for TROP2, 16.57% for LIV1, and 3% for HER3.
- Grade ≥ 3 adverse events occurred in 25.06% of patients.
Why it matters
The findings suggest that neoadjuvant ADC strategies can achieve pCR in early-stage breast cancer, but response estimates differ substantially across tumour subtypes and ADC targets. The high heterogeneity in the pooled analysis and the reported frequency of severe adverse events are important context when interpreting these results. The subtype pattern supports further evaluation of biomarkers to identify populations most likely to benefit.
What to keep in mind
Heterogeneity was high (I² = 92.8%), and the evidence was predominantly from phase I/II trials, with only two phase III studies included.